How many cars these days have a 90 amp alternator??? Do your test again with a realistic alternator that is fitted to a car. Even my 2006 car has a 120 amp
We provide systems to the marine markets as well as automotive markets, where there are broad ranges of alternators. A larger alternator does not inherently mean you no longer have to worry about thermal damage to your alternator. I have seen 180A alternators melted from consistent direct lithium use without current limiting. If you're adamant about not protecting the alternator with any devices, you require exceptional cooling to the alternator. In many systems this is unfeasible to add. So, in turn, the alternative is to insulate against the risk of high draw by using current limiting systems.
Depends on the system - A possibility is that the voltage coming from the alternator will suddenly spike high- especially if there's not anything else on the circuit drawing power any more. Current immediately going to zero can, by calculations and in reality, cause that voltage to spike highly even for a moment. This can cause potential damage to the diode pack, the regulator system, or other electronics on the circuit. I'd argue it's of secondary risk to the actual overheating aspect, but it's certainly something to still be aware of. Ben
Hi Andy, Well, a couple of things here. If it's a current limiting regulator then absolutely, that could very well be suitable. If it's a current limiting thermal regulator that monitors the interior of the alternator then, again, could very well work. Typically find that most temperature sensors place themselves on the chassis of the alternator or on the studs of the alternator- neither of which are really the areas which are getting uncomfortably hot when running at 105% and 60% of cooling. Best way of doing it, in our opinion, is stopping it from getting too hot in the first place and just controlling the current and voltages with an intelligent system. Hope that helps, anyway! B
My Balmar alternator goes into a low amp output when it gets hot. I set the belt load manager to stage three for more current to charge my lithium house bank, against the Balmar recommendation to limit current more significantly. I am looking for the sweet spot to keep current high without a thermal cutback.
You seem to have quite a test bench. I don't know how you are set up. I have been running 4 lithium, 200 AH batteries for 4 years now. I have a 45 amp hour lithium power converter for the shore power and generator. I am connected directly to my 160 amp alternator in the motorhome. I commonly run the batteries down to 20% charged. When I start my coach engine the lithium typically get 35 to 45 amps from the alternator. As I get on the road, with higher speeds, the charging usually goes to 80 amps. My coach is now cooling the alternator. I don't understant your conclutions. You are not cooling your alternator. My understanding of alternators is they will only supply what they can. This is governed by RPMs and the voltage regulator. As your load goes up, the voltage, even regulated, goes down. You cannot charge a battery with a voltage lower than what the battery currently is supplying. Say the battery is at 13.0 volts and the alternator is regulated for 13.4 volts. As the amps go up the alternator's voltage will drop at the battery (especially due to voltage drop across the length and gage of the cable between them). When the alternator voltage gets to 13.0 volts, it will not produce any higher amperage. The most curent I have ever seen going to my batteries is 80 amps. I also have a 100 amp fuse between the alternator and the battery bank.
Hi CFP; Broadly- I'd agree with you. However - "My understanding of alternators is they will only supply what they can" is kind of the crux of the issue. There are many installs (particularly on boats) that do not have great cooling of the alternator. Even at relatively low RPM the alternator is sufficient to hold about 13.0V on the output- and that is enough to charge a lithium battery that is below ~50% SOC. The incredibly low internal resistance of lithium asks for everything available in the system. If the alternator is capable of supporting an elevated output voltage onto a discharged lithium battery, we'd see full load for an extended period. There are some systems out there that induce volt-drop to current limit in extremely dangerous ways- a Narrowboating tendency (and an actual nightmare) is to run 30ft of thin cable, winding up and down, to induce voltdrop and therein current limiting. I'm surprised there haven't been more fires, there. Are there systems that are probably sufficiently cooled to not require DC/DC chargers? Yes- though they are certainly not the norm. I've had to deal with a number of customers who were not as lucky as you- alternators that had the internal soldering melt and stream into the running tracks, for example. There've been instances in the past where, before we had our new higher power units, we simply told people to carve improved ducts into their boats and just direct as much air as possible through... and it worked. But that's not always an option. There's always exceptions to any rule, but we believe that a properly rated DC/DC charger system solves any potential issue with lithium in the most responsive way.
@@SterlingPowerLtd The boat is different, because the alternator is bigger,..bigger alternator means bigger power,..to move bigger alternator you need a bigger engine But we are talking for normal cars , 4x4, vans, most alternators are 140A , 160A ,..180A I have seen the test generally speaking when you hook jump cables to the battery and the 12V 200Ah lithium battery, the car will not charge lithium batteries more then 300-350 watt when it’s on ,. this is pretty much standard ! You might get around 400-450 watt while driving, and a spike of 500 watt from harsh accelerating ,..but generally speaking standard current is around 400-450 watt while driving So there is non need for DC to DC as long as you have a relay installed to stop the current when the car is off As I said you might be right for boats or big projects house on the wheels ,..but not for cars , vans or 4x4,
Your test is misleading,… first most alternators are 140 amp or 180 amp for vans or 4x4,…not 90 amps like you demonstrated Secondly, you didn’t tell us the capacity of the battery Thirdly the acceleration from that machine was way too high,… vans and 4x4 do not run like your demonstration,zso you better do your test in a van or 4x4 to make you point,..for me your test is misleading
Thanks for your video. isn't this the job of the alternator regulator? I have a standard Hitachi 80A alternator that came with my Yanmar engine charging my 200A (12v) lithium system direct. The alternator reduces charging current very quickly to about 30A as it heats up due to the internal regulator.
Hi Dino! Varies on the alternator regulator. Some are unable to manage the current within safe ranges. I can never advise people to charge lithium directly from an alternator due to a number of reasons including voltage control, BMS shutdown and the high chance of causing alternator damage when the current being requested is greater than what the cooling is applicable for. There's a catamaran manufacturer that I keep having this conversation with, and I keep getting calls from their external repairmen telling me that a lot of kit needs fixing after when they don't do what I advise. -Ben
Depending on how the current limiter works, then it may well be a sensible and safe option. There are not many simple current limiting items out there. Best, Ben
I can charge my lithiums @ 200a direct from alternator with no issues. If you use the right battery then its no issues. The quality of the BMS and Cell management system goes a long way towards increasing performance.
Hi MOS, In our tests with a variety of batteries and BMS, and indeed tests that have been held out by our major competitor, we find that the incredibly low internal resistance and ease to charge a lithium battery off of an alternator is rarely without problems. I believe our blue competitors video ended with an alternator very much smoking. That said; we do have customers who simply use our non current limiting charge systems on lithium and rarely complain; so perhaps we are being overly cautious, but that's the side I'd rather be on than recommending a potentially risky setup. -Ben
@@SterlingPowerLtd The blue competitor used a battery with no BMS at all and of course it will fry the Alternator. Keep watching and they use a BMS later in the video with no issues. Ive been using alternators in 200 series, Hilux, Patrol, Dmax, 100 series, Hiace and many more and not a single issue. I use a Brushless, Sealed, Watercooled 200a unit with no issues in my own car. Not many lithium batteries can be charged this way but they are on the market and cheaper than the "green, Orange or Red" ones and have a 200a BMS so discharge and charge rates are much higher.
@@VEOPengineering Interesting- I'll have to rewatch! Most BMS that I've come into contact with generally just facilitate the lithium charge and then put the lithium drain and demand directly onto the alternator - until high current causes a BMS disconnect. I'll be sure to do continue my research and testing, as I have to do with everything in this market, I merely like to play things safe when representing the company :) -Ben
@@VEOPengineering Hi Toyo; Thanks for that video! It was genuinely an interesting watch. I find the very variable voltage and current interesting, you may benefit from an alternator regulator, but the fact that the alternator never really seems to rise above that comfortable 51' mark is quite fascinating, The M/D is doing more battery tests today, largely comparing the market. Perhaps we've been overly cautious so far, but I'd have to do more tests before I can be certain. Thank you for your knowledge though! It is always good to be challenged by a new view, pushes us to continue our research.
Why, during testing, did you put load on the lithium battery ? Most rv driving have no load on the lithium battery. Would not having a load decrease the damage to the alternator ?
He's trying to illustrate what would happen if you have a deeply discharged battery/s and the alternator is running flat out for hours. It will kill it. Remember 100amps over and hour is 100ah. The lager the bank the more charge is required.
There are many factors not being mentioned here depending on the application. I don't know of ANY scenario where your lithium house batteries (assuming we are talking about RV/Travel trailer/5th Wheel) are going to be 3 feet from your alternator connected with what, 6 awg wire!? a boat maybe? In a typical, real world setup, considering you are trailering something, there could be anywhere from 15 feet to over 20 feet between the alternator and the batteries AND, with the connection being through the 7 pin connector, is running over like 16 awg wire. You aren't getting anywhere near the kind of current you are demonstrating in your bench example. Maybe do another test using a real world example? I would assume you would agree that distance and wire gauge have a major impact on the current over a line.
Hi- On the one hand, you're broadly correct about what you would see in that case. On the other hand, you're using a cable (one of the leading causes of electrical based fires on vehicles) as a resistor to drop voltage and to drop available current flow accordingly. We're not particularly fans of intentionally using insufficient cabling as a way to current limit because of the massive risk to vehicle, vessel and life- not to mention the lack of ability to get insurance or to actually meet the warranty needs of your equipment.
HI, i have heard of the alternator connected to an AGM battery and the AGM acts as a 'reserve tank', the AGM then passes through a 500amp stinger regulator to a 100AH lithium phosphate battery (without any issues). Does that sound feasible to you? I'm no expert.....Thanks
Hi Shaz, Without a method of limiting the current being demanded from the lithium, in this system, I cannot recommend it on behalf of Sterling Power. Lithium batteries have incredibly low internal resistances and as such will request all available power, readily. This is the problem. If 300A of charge is available to the battery, it will request it. This often leads to the BMS tripping out to 0V, refusing charge, or overworking the alternator. It will likely be fine for a period of time, but I cannot recommend it on behalf of the company. -Ben
Hi there, Are you looking to replace the starter battery or your rear batteries? Lithium interacting with an alternator directly is always going to be something to be aware of, as you could damage the alternator or you could very well damage the lithium. B
@@SterlingPowerLtd exactly, i am thinking about both? However after looking into this more not sure. I want to start producing a lithium battery pack for the Prius gen2 that is affordable.
@@lookingupwards8652 Hi there, Generally lead acid is perfect for a starter battery - then if you would like a lithium bank in the rear to run your appliances and equipment off of, we would utilise a battery to battery charger to facilitate charge from your alternator side to your lithium side safely.
Ok but by not measuring the temperature while loading "standard" lead acid batteries how do we know this is not a normal functionning temperature for an alternator ? Most probably you did that however.
We did not run that in this test because lead acid/alternator interactions are already extremely well known and documented. Lead acid batteries paired with an inverter can cause alternators to overheat, but this is extremely rare, whereas the high draw from lithium is essentially inherent in its makeup. Lead acid batteries have their own noticeable inefficiency and internal resistance, this resistance can be overcome by elevating voltage beyond that which the manufacturers recommend, but generally they will only draw a very modest flow. Lithium due to its very low internal resistance will accept current as readily as it is available. Yes, were we doing this as part of a thesis we should have likely covered a control experiment side-by-side, but our intention with this test was to show the effects of lithium on an alternator in an unmanaged situation, versus the effects of various battery chemistries on alternators.
do you have a product that can take two alternators two start batteries and a 650 am^service just had a customer ask for an upgrade on a lagoon catamaran and found your youtube, I already installed your alternator to battery charger on a monohull and it was easy and works perfect ! thank you !
Depends on the alternators and depends on what we're trying to charge in the service bank. If you can give me more information regarding A) Alternator rating and B) If the service bank is going to be lithium, I can advise from there. B
@@SterlingPowerLtd Thank you for the swift answer the boat is a lagoon 50 equipped with 2X D75 Volvo diesels I believe they are 90 amps alternators and definitively going lithium as we need to change the service battery bank, boat has 3X140 AMP acid as service, plus two starter batterie for the engines, boat is also equipped with a 11KW generator with a viltron multi 2500 watt charger inverter, the generator is a stand alone I would not change it starting battery for a lithium, but I would like to know if you have a solution that is safe and easy let's just assume the owner is not a technical person, and I would like to build him and hopefully the next catamarans a better system; one that can eliminate the generator, have a nice day !
@@teknotikpointbiz Hi Tekno! I've had a lot of consultations with various catamaran builders, owners and fitters recently so this should roll of my mind fairly easily. The first thing we need to control is how much current your lithium bank is going to demand from your alternators. If we do not limit the current we will see your alternators gradually degrade due to being ran at 100% continuously while not having to run at the correct RPM to cool itself. The solution is to have each alternator feed onto a designated starter battery, then to have a BB1260 coming off of each starter battery, then go to your leisure bank. The BB1260 is a current limiting charger so will never request more than ~60A on the input. Two BB1260s will offer you with ~100A at 14.4V to your lithium bank while keeping both of your alternators within a safe operating range. Does that sound suitable?
@@SterlingPowerLtd not only suitable , awesome and fast plus not too expensive , easy to install too !, so thank you very much !!! I am looking for the bb1260 here in Montreal you seem to have a distributor, to quote my customer ! if we go ahead I'll keep in touch ! really great to have someone answer so fast ! but now in the case I have to do it on a Saba 50 same setup except the starboard engine is started by the house bank usually would you recommend the same setup as adding a starter battery ? merci et bonne journée !
@@teknotikpointbiz Hi Tekno, Thought this would pop up! Yes; typically we find that catamarans have two alternators but only one side with a starter battery. This would normally pose a problem but Sterling has a solution. The Alternator Linearisation Device (ALD) essentially acts like a starter battery as far as the BB is concerned. In instances where a starter battery is not present an ALD can act in a similar way to clean up an alternator output. Instead of going Alternator -> Starter Batt -> BB -> Lithium, it goes Alternator -> ALD -> BB -> Lithium. Hopefully that helps! -B
I think it is difficult to generalise the statements made in this video. My boat engine has a 115A alternator and that alternator charges a 70AH AGM for the engine and 3x 105 AH LiFePo4 for the board battery (supplies all other electric sources). I've used this setup for 4 years and have not had any problems. Yes, the alternator heats up to 100 degree C and remains on that level. The charging current drops from 95A to 60A within 15 minutes due the alternator getting warm. Bottom Line: if you have the right alternator (power, heat controlled charging) and the right batteries you can do without a B2B charger.
Hello SailingMan, I find it hard to just stick to that statement however. Many boats have insufficient cooling to the alternator and many alternators are not designed to work to their actual specifications. Simply telling someone that their alternator is insufficient rarely solves the problem, so we have worked on making a solution that will always pose a solution and that which stops the alternator getting hot in the first place. It's been pretty successful so far and a number of lithium manufacturers recommend its use directly to make sure the system works.
@@SterlingPowerLtd I would agree that a booster or B2B charger is a safe bet. However, if an alternator is able to deliver more Amps, the B2B would not leverage the full potential of the set up. I think the bottom line is that you need to understand WHEN a B2B charger is required and when you can do without it.
@@sailingman143 Correct, but many lithium companies (and alternator companies, honestly) don't want you to use the full potential, as it's unlikely everything was meant to run at that level continuously. We're working on systems that will integrate with the onboard CAN that most vehicles now have and will allow us to milk systems to their limit. There's been a number of cases where even an alternator running at 60% of its rating gets hot enough to break down- obviously that's one of the extremes but it's something we try to avoid ever going near in the first place. Obviously there are systems out there that don't integrate our kit- but many do and it seems to be something that is growing as time and requirements develop.
Yes, otherwise your alternator will likely be overheating, particularly at low RPM. You'll also run into issues if 1) Your lithium battery is ever full (alternators on zero capacity circuits can be destructive) 2) Your lithium battery fills during charge and the BMS turns the charge circuit off (potential for voltage spike) 3) Lithium may not be able to be woken up by an alternator, particularly if it requires an excitation voltage.
Hi PLT- You can indeed! Disadvantage of some current limiters is that they A) Do not isolate both sides from one another fully, and B) Doesn't actually end up either providing a constantly active load or C) Boost/control the voltage to a sufficient level to help the batteries charge. Problem with A) is that your lithium batteries may trickle to elsewhere in the circuit as their rest voltage is rather high. B) Could prove to be an issue if your BMS ever shuts off. C) could delay your optimum charge time (with that current), or, if the Voltage is temporarily too high, trip your BMS. Hope that helps,
Hi Robert; Beyond it not being covered by most battery warranties and likely not being able to ensure the voltage going to the batteries is actually suitable for the charge- it also is just against the ideals of protection that the system is looking for. The lithium will still be demanding a draw and for as long as the diode is present on the circuit, one of a few things can happen. 1) The diode gets blindingly hot and the voltage-drop actually stops the current flow, but the diode might be flammable 2) It's possible that if the draw is still high but the diode is dissipating the 'excess' as heat, that neither the alternator nor the diode are protected from being overworked. forum.allaboutcircuits.com/threads/current-limiting-in-battery-charging-circuit.126240/ electronics.stackexchange.com/questions/415563/lithium-ion-battery-charging-problem Your options are either control the field (and thus the provision from the alternator) directly, or use a system like a DC/DC charger to create two independent circuits (IN and OUT) so as to properly and safely taper the current.
Sorry but I must call foul. Nothing that you said was not true but (and this is a big but) you left out a lot of information because it does not sell your Dc2DC charger. You are correct that an internally regulated alternator will get cooked when charging LFP especially at lower rpms. What you left out is that it is completely safe to charge the LFP pack from a directly connected alternator that has external regulation which monitors the alternator temperature. The goal is still to limit the current but that is done based on the alternator temperature. A very big dc3dc charger will only put out 40A. On my boat, I have a 160A alternator and can put out 120A and not go above a case temperature of 90ºC at cruise rpms. If I run the engine slower, the thermostat will cycle the alternator off as needed to allow it to cool down.
Hello Hayden, A couple of things I'd note. 1) It depends on how the alternator regulator actually responds when an alternator reaches the critical temperature. If the regulator can interrupt the field line and has some means of current control- great. If the regulator merely turns off (therein likely resorting to the internal regulator), it could continue charging at a high current and therein still overheating. If the regulator bucks the voltage down- this is likely suitable enough to stop current flow, unless the lithium battery is particularly empty or if the lithium battery has a large load on it. 2) It also depends on how we're recording said alternator temperature. CAN readings from the core (if measured) would be relevant. Readings from the chassis can be delayed sufficiently to lead to the alternator core still getting hot enough to be damaged before the chassis temperature sensor signals a response from the regulator. 3) I have not actually seen much written, videod or discussed about actual current limiting of alternators. It's written in passing in some item descriptions (of some regulators), but it is not yet written as an exception in the warranty of many lithium batteries or alternators. Whether this is because lithium and alternator companies are slow to respond, or because they do not believe it is suitable is unclear. 4) A 40A BB is not particularly large. 40A would be the second smallest of our newest Saturn range, where we have items from 25A up to 200A at 12V. The 120A BB would suit you perfectly.
@@SterlingPowerLtd Thanks for the reply. 1. None of the external regulated alternators that I have experience with have any form of internal regulation. They have all been B-type (positive field wire) so if the regulator is not working neither is the alternator. That is a safety issue because with an A-type, any problem with a short in the field wire would cause an unregulated alternator runaway. 2. The alternator temperature is taken from a stud on the case if one is provided by the mfr or from the hottest location on the case per a thermal camera if available. If neither of those are available, run the cold alternator for 30-seconds, then shut off and feel for the place that gets warm first. I used this method and then installed the probe in thermal paste and held it in place with large hose clamp with insulation over the top of the probe. It is true that the innards are much hotter than the case but the manufactures of these alternators give safe limits for the case temperature which are usually around 100ºC 3. There are many sources of info on external regulation for charging LFP battery banks. They are available from Balmar, Electromaax, Wakespeed and others. Wakespeed can even use power output from the ECU or engine RPM to reduce the output so that big alternators do not overwhelm small engines. Here is a video to a 40hour deep dive into external regulation. ua-cam.com/video/3uWWysz4blw/v-deo.html 4. Just using a large DC2DC chargers would not limit the temperature of the alternator. In my case, if I need to motor at less than cruise speed, my alternator will still get too hot even when limited to 120A. For a system that is designed to charge large LFP banks, I prefer to have a smart regulator that sets the output based on the ability of the alternator within its limits.
@@haydenwatson7987 Hi Hayden! 1) yes; correct. There are both pos and negative field control regulators available, mind. It does depend on how it shuts down, and indeed what it defaults to in said state. Our opinion is that it's better to not let an alternator get hot in the first place rather than to respond to an alternator as it gets hot. 2) Sensible method, though I've seen alternators sustain damage from even correctly 'temperature sensed' apparatus. Most strikingly is a catamaran manufacturer that had both alternators sustain damage in the form of melting internal solder. When said solder dried the alternator did not spin. It depends how critically hot the core can get versus the chassis and how the items respond to said heat. 3) The Wakespeed (WS500, off the top of my head) is the only unit I'm aware of that claims it can current limit and can actually feasibly do so. Thank you for the video all the same. 4) Correct- however a correctly rated BB system would not overheat an alternator even at idle- and in the situation where other loads are also competing for the BB's input (and potentially then bringing the alternator to run harder than expected) the BB will automatically downrate. Hope all the points come across as I intend them to!
Very interesting, my 60a Sterling B2B gets too hot in summer charging 345a/hr of lead acid, in my motorhome. I am adding another to reduce the loads and temps and reduce charging times. Fine in winter.
Hi Simon, That is quite a bank for it to fill but I hope the fan on it is sufficient to keep it running throughout! So long as it is in a sufficiently ventilated area the fan cooling should help itself run continually at an expected rating. A second BB will definitely take some of the stress off the first one, though, so long as your alternator is comfortable with this combined current! If you need any assistance, give us a shout, B
Actually, it is quite a straightforward solution, this is needed. All we need to do is install a heat sensor on one of the components, that heat up the first. Using a simple op-amp circuit, the reading from the heat sensor will disconnect exciter current to the rotor, until the temperature comes back down, within allowable level and then the exciter current is switched back ON. Anybody with a reasonable experience in Electronics, can put this circuit together.
Do a test like in a real world scenario .Most people would have a lead acid battery in parallel. That would take the load off the alternator with it charging the lithium & not drawing too much current itself off the alternator. PS time to go back to school my friend!
Hi Andy; A lead acid battery in parallel is not, on its own, a protection against high current. It can be a protection against voltage spikes, but it can add additional dangers of its own. A lead acid battery in parallel will not take the load off the alternator at all; there is still capacity on the circuit to be filled. It is now lithium (high draw) + lead acid (low draw). The low draw does not eliminate the presence of a lithium.
@@SterlingPowerLtd But the lead acid battery at full charge will pump out power to charge the lithium & help out the alternator. Check it out for yourself with an amp meter?
@@andyb6120 That's not how it works in my experience or in my measurements. Because lithium rests at a higher voltage than lead acid throughout much of its operating cycle (A 40% SOC Lithium is ~12.8V at rest, a 100% lead acid is about 12.8V at rest) there is simply no logical way for a lead acid battery to be able to support charging a lithium battery over 40%. Voltage can only 'flow' from itself downwards. IE, a 12.0V charge voltage will not charge a lead acid battery effectively, because a lead acid battery at above 12.0V will draw nothing. Further, flowing from a lead acid battery into a lithium battery can actually be dangerous. In the event that you do put a 12.8V lead acid battery onto a
Hi Pascal, I believe some alternator regulators are being introduced into the market that have current limiting, or at least being theoried to have current limiting, but a regular alternator regulator will not be sufficient, even with a temperature sensor. Some clients and customers are happy to go ahead without them but I must always warn them to be aware of potential alternator degradation. B
Even with a 300A alternator, it's sensible to have a correctly current limited system. We've done nothing untoward in this system to force this response. There's a reason why every single lithium manufacturer recommends a correctly equipped system. If your lithium battery bank has a relatively low charge rate (some Lithium batteries have a charge C rating of as low as 0.1C- though thankfully this is very rare these days), specifically a charge rate underneath what the alternator is rated to, you'll likely see no charge going into the battery bank at all. IE, you'll see the alternator engage, provide up to their max rating very quickly (due to the low internal resistance of lithium), exceed the C rating dictated by the BMS, and the BMS turns off the charge input circuit. Alternatively, if the C rating is above what the alternator can provide, you'll see the alternator running at max yield for prolonged periods (particularly on a well discharged battery), and when operating at a low RPM but high output, you risk seeing serious degradation or damage at the alternator. We'd rather you have a succinct, correct system that runs for a long time than having to change the system (or replace the alternator..) shortly after. We have clients operating on twin 400A alternator truck systems and twin 300A catamarans that utilise our items with no issues.
Hi Jade, We believe the best way of doing this is with the alternator going directly to a dedicated lead acid battery as a buffer, most starter batteries on systems are sufficient for this, and then using battery to battery chargers to provide the perfect maintained charge to a target lithium bank. -Ben
@@SterlingPowerLtd Thanks Ben. Yeh I'm doing that with my house battery system. There is a company here in Oz that makes a lifepo4 battery that is suitable for winching/ starting and can be installed under the bonnet. They are a reputable manufacturer and the batteries are definitely not cheap, so I have no reason to doubt their claim My concern was, due to lifepo4 having such low resistance to charge, and with a second battery also running via DC to DC charging, plus the usual other vehicle loads, perhaps the alternator might burn out? Because the battery might be capable of drawing 100 amps continually and it was my belief that alternators don't like doing this. I wanted to take an alternator and then current limit it to say 75% or so, so that even if it is pumping this current in for a long period of time, it is still not running continuously at full capacity. Does this make sense?
@@thewhiteoxoverland Hi again, That's more or less exactly what we've found, thus why we try to keep lithium and the alternator away from interacting with each other. Lead acid is great as a starter battery, great at cranking and doesn't put unnecessary drain on the alternator- and never is at risk of just disconnecting if a situation goes out of what it prefers. Lithium as a starter can be done, I know it can be done because we've done it for the M/D's tractor, but it's never something I'd advise to a client. Alternator -> Lead acid starter -> Battery to battery chargers -> Lithium bank. That's the only way we recommend
Hello Geoff, Very unlikely. It's the internal temperature that is rising at an incredible rate and even a significantly increased airflow on the outside of the alternator will only lead to a moderate-to-small increase on cooling on the inside. Alternators are not made to run at their rating for prolonged periods, and often do not run at the correct RPM for cooling when running on lithium batteries. Battery to battery chargers are really the only option we and many other lithium battery manufacturers recommend. -Ben
I've successfully added a fan to a small case hairpin alternator at 160amps, and a 100ah headway lithium. I pull 1000 amps burst power for car audio, my alternator duty cycle is indeed 100% and beyond. 30k miles so far, major abuse on hot days with the AC full tilt, and ticking right along nicely. I mounted a high RPM, high flow 80mm delta at 84cfm to the rear of the case, where the rectifier is. It's quite a performer, and just a plain, stock Toyota small case hairpin. Powers a 10,000 watt stereo setup, intermittently, of course, till the batteries are low. Then I take a break, and that single alt charges the bank back up with the AC going for a an hour or so, and do it all over, in the sun, peak heat of Summer even, over and over. Try it out, you may be surprised at the results!
Thank you. Very interesting video. I'm looking into lithium charging from a smart alternator an a new van ( using a DC to DC charger). With a particular interest for tick over speeds. Does a smart alternator controller look after the health of the alternator at low speeds better than the traditional alternator controller? Many thanks
Hello Jay, No, not that anyone is aware of. Smart alternators are even worse with lithium (if without a DC/DC charger) because smart alternators, to minimise the potential charge time, normally operate at much higher voltages than we would otherwise want going onto our batteries - which in the situation of a lithium with an integrated BMS would often just mean the BMS disallows further charge - meaning you're getting no charge through at all. DC to DC charger will always be our recommendation for lithium and alternator systems.
@@SterlingPowerLtd Many thanks for your reply. Just as a matter of interest, I have noticed that there is some sort of controller on my euro 6 van negative battery terminal. This backs up what you say about using an earth wire from the charger all the way to the vehicle battery. Using the chassis for the earth connection is likely to upset the operation of a smart alternator
@@jaybee258jb Hello, We actually recommend using a common and direct negative for a different reason. When boosting voltage there is some current that runs down the negative line. Passing current through the chassis of the vehicle is horribly inefficient, as I'm sure you can imagine, and can lead to unit damage.
Good day, I have just bought an alternator to battery charger (Sterling AB12160) hoping to be able to charge lithium batteries, I note with regret that this is not the case. Are there no solutions? do I really have to go to a B2B charger? Thanks for your answer.
Hi Candro, I'm not aware of any BMS that can actually taper and limit current at this point in time. They simply disable the input MOSFETs if the current is exceeded. This means the charge rate is 0, not whatever you set the limit to. Thus why many lithium manufacturers recommend having a properly lithium suitable circuit. Best, Ben
@@SterlingPowerLtd I was thinking that as per charge controllers, there could be a way to limit the charging current directly from the BMS.("closest thing" to the battery terminals and the one who "protect them"). Anyway, I am bitter due to the fact that BMS app (freshly installed) that I have, has few drawbacks. I will look for the available features. Thanks!
@@candro5510Hi Candro, Ultimately, in the long term, it's possible. There are batteries on the market with integrated DC/DC chargers that actually do similar behaviour- but I am not aware of any BMS that simply limits current. IE making 14V 200A available to the BMS, it only draws 50A. Ultimately most BMS primary features are distributing the charge to the cells equally and offering protection. The significantly elevated cost of having a current limiting charge circuit would render many batteries far more expensive - rather than just having a lithium suitable system. All BMS I've seen so far simply turn off the input when charge current parameters are exceeded. They may have a timer associated or not, but I'm not aware of any that actually taper current.
Can you clarify something for me? Given you require a Dc to Dc charger and the donor Dc source is normally a lead acid starter battery then is it the case the lead acid needs high cranking amps CCA to optimise the capability to charge lithium batteries quickly? I understand the Dc to Dc charger if a smart one will optimise the charging process and give undervoltage protection to the donor but I can't seem to find advice on donor battery choice, obviously a 150ah donor battery will have better capacity than a 110ah etc but to optimise time charging in shortest possible time there's no good having a lithium battery accepting 90 amps if the current drain on the donor can't give it without damaging the donor battery. (Which the charger won't allow anyway). So is the choice of donor battery all about Ah capacity or does CCA factor in to charge times and donor battery protection (i.e not wanting to put the donor battery out of condition over several months)?
Hi Ray, The discharge capabilities of the lead acid starter battery is largely irrelevant. Its purpose in the circuit is not to power the BB, but to stabilise the alternator output. Without any sort of accumulator on the input the alternator voltage will be erratic at best and destructive at worst. The lead acid battery does not provide power to the BB- it just holds the alternator steady. The BB draws power directly from the alternator VIA the studs of the starter. Nothing is pulled from the starter itself. You don't even need that sort of massive input battery. Systems as small as 60Ah have been suitable. Ben
That's why you ALWAYS choose HALF amps for li on or lipo . 60 Amps lead acid baterry is equal to about 30 amps and less for lipo Lipo are amp suckers due to.less resistance
Why did you not tell the battery manufacturer and model or at least give the specifications on it. I’m pretty sure that battery has no current limiting or controls in it. You should tell the whole story, not just the parts you want to push. Why did you not give the RPMs you were running the alternator? At a very slow engine idle of 500rpm, the alternator will be at 1250 rpm.
Hello Kevin, The battery was an AL12100 with the over-current shutdown disabled. As far as I am aware, there is not a single lithium battery on the market that has current limiting as part of the BMS. They have over-current shutdowns, that cause the battery to turn off if the current is exceeded. Had we not turned the protections off, the battery would not have taken any charge at all. Had we had multiple batteries in a larger battery bank, the protections would not have been exceeded in the first place. Our blue competitors have done the same test, their alternator started smoking. At a higher RPM, cooling will be increased to the alternator, so long as decent cooling is even available, but this is not always possible.
What if you don't have a alternator but a gear diven, oil cooled, brushless DC generator and a external voltage regulator, my dc generator is a Delco Remy 225 amp. What would you recommend for charging lithium batteries
Hi James- Hard to say for sure as it's not something I've had years of experience recommending on, compared to alternators, though I'd imagine it's a similar case. Most items were not historically designed to run at their limits continuously and so will likely benefit from the current limiting control that DC/DC chargers can provide. Talking to the manufacturer would be the first step, as they can probably recommend RE: limitations and capabilities. If they think overheating is a risk, going down the route of a DC/DC charger would be our recommendation. Ben
I have a 125 amp alternator on a diesel pickup that has no load to speak of..no electric windows, seats or AC and LED lights so very little draw BUT I am putting in a 12 volt AC split which is rated at 60-80 amps depending on how cold one wants if the AC split is only running while driving can I just run it off the main battery to a lead battery with a solenoid so it cannot run while truck is off? Or would it still need the DC to DC charger...it seems it would be fine since at max it would be about 80% of alternator capacity but want to make sure :-) and NOT burn up my alternator
Hello Fedorico, Ideally we'd be running the split off of a leisure battery bank at the rear, so as to minimise the load on the starter system and minimise the possibility of you being left with a drained starter battery. That said, assuming you have a system which only engages when the ignition is on and the alternator is running, the alternator should cover those loads fine and happily. Ben
I have a 2000 F350 with factory wiring going to a camper containing 2 - 100ah lithium battery's. Won't the factory 12 or 14Gauge wire limit the alternator output to the lithium batterys in the camper?
Hi Bill, I probably wouldn't advise using one of the primary sources of onboard fire (the cabling) as a resistor when charging lithium banks from an alternator. If your lithium batteries are low, or providing to a load at the same time, and your alternator is at a decent RPM, even with massive volt-drop between the alternator circuit and the lithium circuit you'd see a lot of current flow.. and if that cable gets too hot or degrades over time, you have a threat to life onboard. We'd recommend current limiting via DC/DC chargers in your case. Ben
Many regulators don't have that capability- there are some exceptions, but they certainly were not available at the time. There also does not appear to be much actual noted work regarding them making lithium batteries and alternators suitable for one another. If we end up testing one in a setting such as this, I'm sure a video will follow.
question is , why are you charging a dead lithium with your alternator ? in a car you would never see this unless you ran ur lithium dead , and then it shouldn't start ur car and you would be forced to use a PSU / charger ..... am i missing something ?
Hi Mazda; Most lithium batteries are not in a starter battery position, if they were they would have to be rated for the cranking discharge rate (which would often require more premium cells) and the performance you would get from one in a starter battery position vs a lead acid would be negligible. As such, we often advise (when advising RE: batteries) lithium in house battery positions, thus battery banks that are likely to see fairly sustained and continuous use. In campervans or boats that are not plugged in overnight and don't want to run a maintaining engine overnight we can see discharge from those batteries for the next day. Many people like the ability to charge their batteries from their alternator when running, and thus when the fairly drained lithium bank is connected to the alternator, we would see the alternator output spike to maximum output until the batteries were full. We see this with one of our fitters now. They are using a non current limiting charger on some fairly premium boats. Works great for a while, but they often need an alternator 'update' after a few months or a year of use. Hope that helps; Ben
@@SterlingPowerLtd i see , I use them as starter batteries and high power audio where we dont discharge them while the vehicle is not maintaining them and I guess we do use more premium cells . Normally for a system using batteries that get discharged we use a regulator with load control built in so the alternator slowly applies its amperage and it does not full tilt to begin with . Also due to the low c rate on non premium cells they prefer to be charged slower .
@@mazda2284 Hi Mazda; Correct regarding the low C rating on many cells; exactly why we need a current limiting charger in many cases. This is the direction that basically all of the power distribution companies are going down the route of, and the same route that many of the lithium battery manufacturers actively recommend for both alternator and battery safety.
Hi John- At present? Other than a battery to battery charger (IE, a current limiting charger), not really. We're working on a current limiting alternator regulator- but we're still finalising the code, so it's a minimum of 6 months away. Ben
@@ThreeFineWonders Hi Charborne; In theory it would make alternator to lithium direct charge safe and as such thus be a replacement of the BB in that sense, but it would miss out on a lot of the other benefits integral to the BB. Alternator regulators are often not as intelligent and as such you may not be getting the most perfect charge pattern which may affect charge time, you may also see voltages vary slightly more than you would through a BB. If your battery bank is happy with a slight range of voltages and your main concern is protecting your high powered alternator, then the current limiting alternator regulator will be ideal. I doubt the current limiting alternator regulator will be cheaper than a BB, but I've got no true idea of the cost to public as of this moment. Other, higher power BBs are in the works actively. -Ben
@@HWR1JZ are you suggesting to put a DC to DC charger between the alternator and the lithium battery? What is the difference between a DC to DC charger and a battery to battery charger?
Hi Terry, While our engineers are working on a newer range of alternator regulators- our current regulators are not current limiting. If you're running lithium you need current limiting otherwise your alternator, as shown, gets pretty uncomfortably warm. BBs are our recommendation at present until units currently in design and prototyping reach the public market. Cheers! B
@@terryscully3272 Temperature sensing is done off of the studs of the unit rather than any internal thermometer to keep an eye on the coil. By the time the studs get hot, because the coil gets so hot so rapidly, damage could have already been done. This also doesn't solve the issue of maximum current going down cable. This could blow fuses and burn out cables if you weren't prepared for this level of current draw. If you were prepared for the current draw it might be meaningless anyway as most lithium BMS' actually also have a current shut-off parameter. Once it gets slammed with an uncomfortable current the whole BMS will disconnect and you now have a paperweight at zero volts. Further, would you rather a unit that keeps charge continually and at a safe rate or would you want something that disconnects unexpectedly? I understand your wishes, genuinely, but with the current regulator it just isn't an option. Down the line we have plans for a regulator that can solve these issues, but that's a story for another video, when it's ready.
If my travel trailer has one, 100 Ah lithium iron phosphate battery hooked through the 7 pin connector of my tow vehicle, won’t the small wire itself limit the flow of current to the trailer lithium battery thereby protect the alternator?
Hello Stuart, I don't think I'd ever recommend somebody to use thin cable as a means of limiting current. It sounds like a one-way route to hot cable and a potential fire-hazard..! -B
Wow an interesting and very telling demonstration. I have just ordered some lithiums for our boat so am currently looking into the best way to charge of the engine
Hi Boatingtube, While we are actively developing an expanded BB range and we do have other current limiting methods in the pipe-line, at present our best and incredibly highly recommended method of current limiting would be to go down a battery to battery charger route. Four stage charging, customisable voltage output, current limiting- can't really go wrong. That said, as our BBs can be ran into parallel you do run the risk of just having the opportunity to run your alternator at 100% anyway, so never have a BB setup that is more powerful than 80% of the rating of your alternator. If you need any further clarification, ask away B
@@SterlingPowerLtd thanks for the reply, there is definitely a gap in the market in this space as none of the big vendors have a perfect solution, paralleling up B2B's is a solution but becomes costly and a little cumbersome to install. I would love to see Sterling add some additional capabilities to update your alternator regulator to support Lithium's and adjust the field based on temperature sensor like the Balmar but at a less ridiculous price and supporting negative field alternators for us here in Europe.
@@Boatingtube NEGATIVE FIELD?? Why on God's earth would you tolerate such ridiculousness? Force your suppliers to STOP creating NEGATIVE FIELD PRODUCTS. PATHETIC.
@@Boatingtube I'm fully aware! Your alternator regulator ideas have been thoroughly thought of and is on a production pipeline but has been put behind the development of some other products. I don't know why, particularly, but alas I'm not in charge! Adjusting on temperature really isn't a perfect method. The idea we have in mind is far more comfortable but I'm not really allowed to talk about it publicly because I know for a fact that some competitors like to watch development, too. :) Watch and see. We have a few things that I want out and I'll be sure to push them heavily, both on the UA-cam front and on the mail front, as soon as we have them good to sale. B
Interesting. We have the Sterling Alternator to Battery Charger with AGM batteries and two banks. Replacing the AGM bank with Lithium. The Sterling is a few years old and cannot be configured to Lithium. How do I keep the current setup and add a product, e g a battery to battery charger, to the current config to save the alternator? We got both an alternator and an old battery charger connected to the In ports in the Sterling. Can Lithium also wreck the battery charger?
Cheap and dirty may do it- but that's not something we could ever necessarily recommend.. It'd be crude, could lead to uncomfortable heat generation, and the naturally varying input (Current et voltage) could lead to complications in getting everything operating quite how you want it to. Or- you could get a battery to battery charger.... :)
People have been experimenting with it on Will Prowse's forum (DIY SOlar). Most folks with relays are introducing resistance unknowingly by running the NEG return through the chassis. This typically knocks charge acceptance down to about 0.32C.
How about limiting the current with a 1/2 ohm power resistor? Given the difference between alternator ~14v and discharged battery ~10v the max current would be 16amp (4v/0.25ohm) which would reduce load on the alternator both at max discharge and when the BMS cuts off charging at the top. Would that work?
Hello Rani, Assuming everything is constant then yes, this would be fine. But the variability in charge rate, alternator output voltage, battery voltage- The calculations for the majority of the period would just not be correct. We believe thus far that a DC/DC charger is the best way for both protecting the alternator and the lithium system, and we generally find that vehicle and boat builders and lithium suppliers all seem to agree with us there, too.
@@SterlingPowerLtd Hey - thanks for the reply. Assuming the assumption that the much voltage delta is less than 5v, this would solve both over-stressing the alternator and the cut-off event when the battery is full and the bms shuts off charging. While I agree DC-to-DC is a better solution sometimes a $100-150 cost (charger + cables+...) is an issue and sometimes space (eg., on class B vans or truck camper) does not allow for DC-to-DC charger. My question here is not if it's the perfect solution or if DC-to-DC is better, my question is if it has any downsides - apart from slower charging (especially as lithium reaches max voltage - in which case it's probably better for charging to be slower at this stage) - does it have any risk or would it solve the alternator issue?
@@ranig2848 I frankly would not know without trying. I believe the only definitive option to protect the alternator is to limit the current it can draw in the first place. A resistor across point A to point B may deter rate of charge by limiting the differential between the two- but with the incredibly low resistance inherent with lithium I really cannot guarantee that this would still protect the alternator. Our alternator to battery charger (non current limiting) applies a resistive load between the alternator input and the main output battery whenever the unit is in an alarm/fail state (over temp, over-alternator temp etc), and if the leisure battery is still lower than the resistor-lowered-voltage of the alternator feed, you're still going to see current in motion. If the alternator is already getting hot, it may not have the opportunity to cool. TLDR: It's possible, but there's potential flaws in the idea (in my opinion).
> How about limiting the current with a 1/2 ohm power resistor? With automotive isolator installs the chassis is often the NEG return leg, which introduces significant resistance. My LiFePO4 banks typically charges at 0.2C in the middle of the voltage curve. Up to 0.35C at very low SoC and ~0.1C near the top. It's not an anomaly; I've been collecting data on it (favorable, unfavorable, all of it) and 0.32C seems to be the average max draw in most installs.
how much is the maximum current that the lithium battery can draw, would a 370 amp alternator be ok to use without a current limiting device. excellent informative video as always.
Hi Edward, Honestly depends on the battery itself and the management system inside of them. Because of the incredibly low internal resistance I honestly wouldn't be surprised at it still trying to request the full load. Obviously this would be bad for a number of reasons. 1) Your cable probably isn't expecting to see 370A being dragged towards the batteries and, unless you have 95sqmm cable, or even preferably on the 120sqmm side, your cables and fuses are going to just disappear in a puff of black smoke. 2) In the instance that your cable is safe and stable to even transfer this current, the battery on the other side might really very much not like this. Lithium batteries should have battery management system (BMS) either within the battery box itself (as with ours) or on the outside with a dedicated BMS. Most BMS trip at a number of things as they care for the battery. You'll see three main routes of tripping. Temperature, voltage and current. If these things aren't monitored, IE you don't have a BMS or the BMS is just terrible, the batteries run a risk of being very unwell and potentially going into thermal runaway which is far more entertaining on a youtube video than in real life. If they are monitored, you have a battery that will suddenly be hit with 370A of current and will probably trip immediately. When that 370A comes through (At an undetermined Voltage- Voltage of which can also just completely trip the battery) the BMS will trip, disconnect the cells from the terminals, and you now have a zero V paperweight refusing to do anything until it reconnects. 3) If, through some black magic, both of the above are actually fine- there's still a very substantial chance that your lithium battery IS asking your alternator for absolutely everything. It may survive for a while at the obscene temperatures it will be pushed to but, realistically, the lifespan of the alternator will be affected. I think the above comments are fair and a decent explanation as to why you want to control this. Cheers, and if you need any further consultation or assistance, I'm here to help- B
lithium can be charged at 1c... that will mean if u have 500Ah lithiium battery will accept 500Ah but as thins great exemple shows us, it will destroid ur alternator... i am about to put together a project like this with 300Ah lithium battery to supply my small loads in the house, such as my aquairum light, filter, laptop, tv...etc... and i will put a video about it and how will work in time... because if its done properly and if its working well... u can supply a entire house.
@@radumihai7419 Hey Radu! Mostly correct; one thing to mention though. Not all lithium batteries that you can purchase are 1C - as much as some people may want to suggest otherwise. Some cells are far better than others, and some BMS limit you far more than others. Always check a spec sheet before purchase so you know exactly what you're (supposed to be..) getting! Cheers! B
@@radumihai7419 Hi Radu, I don't feel as if my knowledge regarding the implementation and installation of lithium titanate supercapacitors within a lithium setup is as whole as it would have to be for me to recommend direction for you on this business account. To my knowledge you can treat them as a standard lithium battery, however I do believe they naturally release charge over time. I never like to advise people to cross-chemistry, particularly if they have different rest voltages. My advice, on the conservative side, would be to say to keep LTOs together and to keep them separate from LifePo4 and also to utilise BMS with them as they seem to have, at their core, the same dangers as LiFePo4 and similar sensitivities. I'd advise you to consult your LTO manufacturers, and if you need further consultation, bring what they say to us so I can learn too :) Ben
Great video! On my boat I have two separate alternators though. one smaller for the starter battery and 1 larger for the lithium domestic. I've purchased a dc to dc charger thinking I could put it between the larger alternator and the lithium battery but I don't think this is the case. What would you recommend in this situation?
Hello Joseph, I'd advise you to direct both alternators to the starter and to install the BB between the starter and the lithium battery all the same. That is hopefully the easiest way to adapt your system. -Ben
Who the hell buys a lithium battery and then then uses an internally regulated alternator. External regulator with heat sensors for battery and alternator.
People who don't know much about lithium, is the answer. Which, by and large, tends to be most of the public. Even external regulators are often unsuitable unless they have current control, it's very worth mentioning. Ben
Earth X has sold a lot to experimental aircraft owners with 60 amp internally regulated alternators ($500 overpriced ND alt from Plane Power). If they have a Hall Effect current sensor, they would see that their high priced alternator is maxed out during the re-charging of an 18 Ah LiFePO battery. Battery sellers are not mentioning this problem or the 32F low limit to aircraft builders.
@@USA-GreedyMenOfNoIntegrity We only advise people down particular routes from our own experience with charging lithium batteries and through particular charge sources. We would love to be able to recommend people to charge lithium batteries safely directly off of an alternator however we do not believe it is safe. -Ben
Hi my 100A lithium has an internal resistance of 25milliohms which seems fairly standard from what I can tell at 50% charge, so achieving 90Amps at 13.6V across the battery terminals as shown in your app is simply physics. I*R=V so 90*0.025=2.25V. This means there is a voltage drop of 2.25V between the battery and alternator, in other words your alternator must be set to at least 15.85 Volts rather than the standard 14.4V. I was just wondering if you could explain how you managed to achieve the current draw. Did you increase the alternator voltage or reduce the internal resistance of the battery, for example by soldering a bus bar across the FETs on the BMS, or can you perhaps offer another explanation please?
Hi there, Our alternator was set, if I recall correctly, 14.4/14.6. I cannot give a solid answer as we did not do any readings of the alternator voltage output at the time. The current we saw was solely because of the lithium battery and their nature of running. Having an almost negligible internal resistance means that they will request all available power. From a mechanical source like an alternator, that means that it will be trying to draw as much current from it as it is comfortable to provide. The alternator did not reach a high enough RPM to justify it's current output, and as such was not able to sustainably cool itself. We recommend BB chargers in order to best control the current coming from an alternator and going to a battery, as do many of the western battery manufacturers. -B
Thanks for your reply. The interesting thing about physics is that its easy to work out unknowns when you have knowns. If it was set as standard, the battery must have a resistance below (14.4V-13.6V)/90=0.0088. So 8.8 milliohms seems very low, personally I have only seen that resistance on a bank that had no BMS fitted as its the FETs in the BMS that adds the majority of the resistance. Perhaps your batteries don't use FETs and have a mechanical relay? I was looking at your batteries and cannot see a specification for the resistance (or impedance) at all. Do you know what it is ? Also whilst asking questions do you know what the final RPM was when it was overheating?
Hi Rob, In the same way that a draw-bridge limits cars crossing, yes. If current is exceeded on a BMS, you get one of two realities 1) If the BMS has an over-current shutdown, the input MOS will simply disconnect and the charge current will go to zero 2) If the BMS doesn't have an over-current shutdown, we'll probably see BMS damage. The BMS has no means of limiting current, merely of disconnecting if the current thresholds are exceeded. Hope that helps a little! Ben
I replaced my old alternator as it no longer charges. the new one gets too hot to touch like the old one. Is it normal for an alternator between 100 and 130 degrees C? engine parts at a temperature between 70 90 C.
Depends on how the alternator is rated to run, honestly. Some are designed to be sturdier and run at higher temperatures than others. Contacting your alternator manufacturer would be my first advised step- and if you need to limit the output from your alternator to keep it at a healthy level, we'll be happy to assist.
@@SterlingPowerLtd I have a valeo 105 amp 14v alternator. When the air conditioner is on, the vehicle consumes 50 60 amps. There is no problem with the cables, there is no voltage drop in the + cable. no grounding problem. battery ok. the only problem is the alternator overheating to 100 130 degrees. Where else could there be a problem? Thnk you for interest.
@@elsequitoelsen4779 I'm probably not the best person to ask regarding what's ongoing with your alternator. I'd advise talking to vehicle manufacturer or a local auto-electrician. I don't predict that there's anything wrong with your vehicle setup itself. Cable probably is fine, or you'd be getting cables overheating or fuses blowing. If the alternator is overheating, the alternator either runs at too low an RPM or is just insufficient to cover the demands. That'd be my considerations.
@@elsequitoelsen4779 why do you consider 100/130° to be too hot? Certainly looking at his test and what he said about Brand name alternators it doesn't sound like you have any problem. Interested in your feedback. Lucy
Hi Liam, Well, hard to say. There's not exactly many current limiting regulators out there at all and most of the current limiting chargers on the market do so utilising the same design idea as our BB product (which we originally got the Queens award for engineering innovation for in the first place). When you're really sitting down and charging lithium there's a few things you want to be in control of and the BB really provides you with all you need. You need to be able to comfortably control and ensure a safe voltage reliably to the lithium terminals because with any sort of notable spike, which can be expected if you're not utilising a controlled charger, the BMS within your battery system may just shut off entirely. Then, until it decides to reboot, you can't do very much with the battery at all. Controlling the current is good, again, for both your alternator and your battery. A heavy current can trip your BMS again or, alternatively, just burn out your alternator. You also need a charge system that will supply power continually in such a way that it can wake up your battery if it ever went down. Some systems refuse to make power available if it's seeing 0V on the other end. We respect the BB isn't cheap but it is incredibly competitively priced for the quality of product you're receiving and it is a very effective carer and charger for your lithium setup, so long as it's installed and set up correctly. We're not just trying to sell this as snake-oil! If you have any further inquiries or want clarification on anything, I'm here to help, B
Hi again Liam, Also seeing on my dashboard that you've commented on other videos but they no longer seem to be there for me to actually respond to. If you want to contact us and inquire about your setup you can drop us a line through the contact form on the website and I'll get back to you ASAP. B
@@SterlingPowerLtd Hi Charles. Yes I removed them, it could have been considered hitting below the belt. MPPT Charge controllers offer similar current limiting and changeover compatibility with Solar. As regards myself, I use raw cells so my custom BMS will behave as I program it to. In all practicality I'm not fitting Li-ion. I can get the same performance from lead, lower cost means higher capacity. Thanks for the feedback Charles. On numerous occasions, I've fitted B2B units parallel to Albright Contactors and comparatively tested them. The difference is marginal (on non-regen vessels). The B2B performs a little better with small batteries in the >85% SOC band. Mostly I find the cable is doing the heavy lifting.
@@scruff7559 No longer is Charles who responds to people on the public front- results tended to be that people ended up getting offended lol. MPPT solar controllers are brilliant because they do hold themselves back and they control the mental voltages that solar likes to produce. But you can't exactly use a solar controller to sort out your current coming from an alternator. On the lead vs lithium front, lead definitely has their advantages and they tend to be on the cranking and price front. Lithium seems to be the route going forward when budget is unlimited and people have limited space or weight accommodation as you can just fit more usable capacity in the same space. If your vehicle isn't Euro6 and your batteries aren't lithium, you can genuinely be better off with other units. Alternator to battery chargers come to mind as you can get the current through at a greater rate and you still get the boosted voltage. If your vehicle is either Euro 6 or you need a charger that does current limit then BB is absolutely the route I'd recommend. Regarding the BB price however- they're not exactly cheap to make. We're not making them for pennies and selling them at their price point just to screw over customers. I like to think that as far as transparency goes in our present market, we rate fairly highly. They do their job and they do their job well. We're working on alternatives in both the cheaper and more premium market, but for now they're our offering to solve most power distribution complications.
I'm glad I saw this. I was going to completely separate my house LifePo4 bank from ever seeing the Altenator and only charge while the genset is on. Now I am comfortable letting the alternator do some work as long as I'm not trolling or idling for long. Boat motors run cooler than cars, and the engine bay is around 105. there are some other factors to watch for as when BMS senses issues, they completely cut off the power, and that would be like having no battery connected to the alternator also a bad thing for them.
Hi Jay, So long as you either have a suitably rated battery to battery charger system, control over your alternators output current, or exceptional cooling to your alternator- you won't encounter any heating issues. The turning off mid-charge is definitely a bit more of an issue for alternators, but there's solutions here as well. The APD (Alternator Protection Device) is one item designed to stop alternator spiking. Otherwise, a lead acid battery onboard and a battery to battery charger will do a lot to protect your whole system too. Ben
Great informative video - thanks a lot for that. If you limited the charge current within the BMS to say - 50 Amps, would you still get the same effect?
Hello again, No, I'm afraid not. The BMS has no means to actually current limit. Once the current is exceeded on the BMS, it simply turns off the charge MOS and renders charge current to zero. Not ideal! Ben
Hi Marc, The temperature sensors largely settle on the external connectors to an alternator. The internal temperature can reach blistering and damaging levels long before it effectively reaches the studs being measured. You also probably wouldn't really want your alternator or charge system to continually cut off after 3 minutes or so and not getting an expected reliable charge. Without a method of limiting the current being requested or transferred through in an almost bottleneck style, there's not really an effective way of protecting the alternator. The lithium battery will ask for everything available, so you just have to scale back what is available until it's safe. Hope that helps; Ben
@@SterlingPowerLtd What Balmar tells me (their extra-large case alternator and 614 reg, with alt and bat temp sensors) is when one gets hot the resistance on the F lead is increased slowing down the charge. I have a thousand amps of lead acid Trojan batteries and I have watched the charge go in the first hour of 20 hours till full. Would not lithium work the same way?
@@marccohen5579 Hi Marc, As the temperature rises at temperature sensor points you will see voltage change, this is true; however it is unlikely that the temperature sensed point on the alternator stud will accurately relay the temperature found at the core of the alternator. The core will get a lot hotter far quicker. Also worth noting that a higher temperature often causes greater resistance, but that's mostly something to take into account with cable rather than alternators. Further, increasing the F lead resistance will slow down the charge rate but with a lithium battery that may very well just end up meaning that you're increasing the heat buildup down a cable. Ideally you want something that throttles the current rather than applies a gradual resistance. Lithium works slightly different to other batteries for a number of reasons. Firstly, most batteries have a fairly substantial natural resistance. I could get a 400A alternator and hook it up to a 100Ah battery and most lead-acids would probably barely engage the alternator. If I stuck a 100Ah lithium on there (with a BMS suitable to handling a 400A spike..) I believe wholly that the lithium would try to absorb everything. Their internal resistance is the problem. They are happy to accept everything made available to them. Another issue arises when we consider how an alternator actually cools itself; for reference it does so by operating hard. A higher RPM drives more air through the internals of the alternator and cools it down- an alternator on lithium, however, causes problems. It will be asking for 100% of the output of the alternator, however because it is so easy to charge it will only require about 60% of the RPM... We then have an alternator running at 100% output and 60% cooling, which even for short periods surely cannot be great for health. We recommend a BB because it's the safest and most predictable way we have, at present, for controlling an alternator so it operates within known and safe variables, if that makes sense. B
Hi Matt. How’s things? I think the Jackery is a very nice bit of kit. The 1000W version has a 1KW inverter which should handle most power tools as it has a 2KW surge ability. The question is if your van installation is good and meets your needs, do we need this as well? There are so many variables aren’t there as we have different setups and requirements. My van has 2 leisure Battery Banks that the Solar charges independently. This enables me to have different Types of battery and different battery ages. So the older batteries can go in Bank 2 that has less requirements. I have a modest Solar array on the van (210W) and not tiltable (is that a word?) so in the Dark Months I can struggle a bit. However a DC to DC charger and updated Alternator cures that problem! I also have a Honda E1000i that is a great bit of kit. However, for me, having portable and additional power source could be a real bonus. I have a Narrowboat that I am refurbishing so I could just add Solar Panels & use a Jackery to provide more power. We also own a small holding. There is mains power in one building but others have nothing so this could be very useful, again with a Solar array in place to plug into. We often have power cuts there! A WARNING however! The Jackery Battery is Lithium. A Lithium Battery will charge at high voltage and when connected to your Alternator in your vehicle will draw as much power as it can take! This can result in a destroyed Alternator so before using the Alternator to charge this up it maybe worth checking with Jackery. They could well have safety circuits installed but in normal circumstances you have to use a DC to DC charger that will regulate the charging rate and protect the Alternator. Stirling Poser explains this here: ua-cam.com/video/ShtGB07fCSs/v-deo.html Be carefull especially if you buy the 1000W version unless Jackery confirm it has a protection circuit installed. For me however, I am pretty certain I am going to buy one, probably the 1000W and the Solar. The ability to tilt the Solar could well be a real bonus in winter! Anyway, all the best. HaHa, just seen the Stirling Power comments! So yes, good idea to contact Jackery!
Interesting, but you keep mixing up Amps and Degrees I think, making it a wee bit confusing, plus the noise man. Sterling might want to think about spending a little money on video production. This is very hard to watch.
Why does the specs on the Sterling alternator to battery chargers say it can charge LiFeON4 batteries but in this video you say you need to use a battery to battery charger? Also if I already have a 3-way isolator can I just install am b2b or a2b between my isolator and my home LiFeON4 battery bank but not my truck AGM starter battery?
Hi Raymond, Pleasure to be in touch-! Reasons behind this are both complex and simple. The AB went through a redesign when lithium batteries were coming out into the world. We made the LiFePo4 setting suitable for the Voltages that we found to be most suitable, but the integral flaw to an AB and a lithium battery is actually in the hardware of the AB. The AB does not have any current limiting potential, and as such can not limit the drain that the lithium battery has on the alternator. We can provide the correct voltages, but we can't limit that facet with an AB. It should be worth mentioning that we have catamaran manufacturers in South Africa who run our ABs directly onto lithium batteries and don't seem to have any issues at all. It's been put forward that we might be being overly cautious, but I'd rather be cautious with our customers than put their alternators or batteries at risk. As for running the BB off of the isolator; sure, technically very possible. We have a number of clients who put isolation switches on the input line to the BB, and this would essentially be no different. So long as it can take the alternator feed off of your starter battery in some manner, it's willing to operate :) -Ben
How many cars these days have a 90 amp alternator??? Do your test again with a realistic alternator that is fitted to a car. Even my 2006 car has a 120 amp
We provide systems to the marine markets as well as automotive markets, where there are broad ranges of alternators.
A larger alternator does not inherently mean you no longer have to worry about thermal damage to your alternator. I have seen 180A alternators melted from consistent direct lithium use without current limiting.
If you're adamant about not protecting the alternator with any devices, you require exceptional cooling to the alternator. In many systems this is unfeasible to add.
So, in turn, the alternative is to insulate against the risk of high draw by using current limiting systems.
Good video. What would happen if the BMS of the battery shuts off for any reason and blocks all of those amps coming from the alternator?
Depends on the system - A possibility is that the voltage coming from the alternator will suddenly spike high- especially if there's not anything else on the circuit drawing power any more.
Current immediately going to zero can, by calculations and in reality, cause that voltage to spike highly even for a moment. This can cause potential damage to the diode pack, the regulator system, or other electronics on the circuit.
I'd argue it's of secondary risk to the actual overheating aspect, but it's certainly something to still be aware of.
Ben
Or fit a temp sensing belmar type system that will throttle the alternators output depending on heat. 👌🏽 maximum amps at all rev ranges then.
Hi Andy,
Well, a couple of things here. If it's a current limiting regulator then absolutely, that could very well be suitable. If it's a current limiting thermal regulator that monitors the interior of the alternator then, again, could very well work.
Typically find that most temperature sensors place themselves on the chassis of the alternator or on the studs of the alternator- neither of which are really the areas which are getting uncomfortably hot when running at 105% and 60% of cooling.
Best way of doing it, in our opinion, is stopping it from getting too hot in the first place and just controlling the current and voltages with an intelligent system.
Hope that helps, anyway!
B
My Balmar alternator goes into a low amp output when it gets hot. I set the belt load manager to stage three for more current to charge my lithium house bank, against the Balmar recommendation to limit current more significantly. I am looking for the sweet spot to keep current high without a thermal cutback.
You seem to have quite a test bench. I don't know how you are set up. I have been running 4 lithium, 200 AH batteries for 4 years now. I have a 45 amp hour lithium power converter for the shore power and generator. I am connected directly to my 160 amp alternator in the motorhome. I commonly run the batteries down to 20% charged. When I start my coach engine the lithium typically get 35 to 45 amps from the alternator. As I get on the road, with higher speeds, the charging usually goes to 80 amps. My coach is now cooling the alternator. I don't understant your conclutions. You are not cooling your alternator. My understanding of alternators is they will only supply what they can. This is governed by RPMs and the voltage regulator. As your load goes up, the voltage, even regulated, goes down. You cannot charge a battery with a voltage lower than what the battery currently is supplying. Say the battery is at 13.0 volts and the alternator is regulated for 13.4 volts. As the amps go up the alternator's voltage will drop at the battery (especially due to voltage drop across the length and gage of the cable between them). When the alternator voltage gets to 13.0 volts, it will not produce any higher amperage. The most curent I have ever seen going to my batteries is 80 amps. I also have a 100 amp fuse between the alternator and the battery bank.
Hi CFP;
Broadly- I'd agree with you. However -
"My understanding of alternators is they will only supply what they can" is kind of the crux of the issue. There are many installs (particularly on boats) that do not have great cooling of the alternator. Even at relatively low RPM the alternator is sufficient to hold about 13.0V on the output- and that is enough to charge a lithium battery that is below ~50% SOC.
The incredibly low internal resistance of lithium asks for everything available in the system. If the alternator is capable of supporting an elevated output voltage onto a discharged lithium battery, we'd see full load for an extended period.
There are some systems out there that induce volt-drop to current limit in extremely dangerous ways- a Narrowboating tendency (and an actual nightmare) is to run 30ft of thin cable, winding up and down, to induce voltdrop and therein current limiting. I'm surprised there haven't been more fires, there.
Are there systems that are probably sufficiently cooled to not require DC/DC chargers? Yes- though they are certainly not the norm. I've had to deal with a number of customers who were not as lucky as you- alternators that had the internal soldering melt and stream into the running tracks, for example. There've been instances in the past where, before we had our new higher power units, we simply told people to carve improved ducts into their boats and just direct as much air as possible through... and it worked. But that's not always an option.
There's always exceptions to any rule, but we believe that a properly rated DC/DC charger system solves any potential issue with lithium in the most responsive way.
@@SterlingPowerLtd
The boat is different, because the alternator is bigger,..bigger alternator means bigger power,..to move bigger alternator you need a bigger engine
But we are talking for normal cars , 4x4, vans, most alternators are 140A , 160A ,..180A
I have seen the test generally speaking when you hook jump cables to the battery and the 12V 200Ah lithium battery, the car will not charge lithium batteries more then 300-350 watt when it’s on ,. this is pretty much standard !
You might get around 400-450 watt while driving, and a spike of 500 watt from harsh accelerating ,..but generally speaking standard current is around 400-450 watt while driving
So there is non need for DC to DC as long as you have a relay installed to stop the current when the car is off
As I said you might be right for boats or big projects house on the wheels ,..but not for cars , vans or 4x4,
Your test is misleading,… first most alternators are 140 amp or 180 amp for vans or 4x4,…not 90 amps like you demonstrated
Secondly, you didn’t tell us the capacity of the battery
Thirdly the acceleration from that machine was way too high,… vans and 4x4 do not run like your demonstration,zso you better do your test in a van or 4x4 to make you point,..for me your test is misleading
Thanks for your video. isn't this the job of the alternator regulator? I have a standard Hitachi 80A alternator that came with my Yanmar engine charging my 200A (12v) lithium system direct. The alternator reduces charging current very quickly to about 30A as it heats up due to the internal regulator.
Hi Dino!
Varies on the alternator regulator. Some are unable to manage the current within safe ranges.
I can never advise people to charge lithium directly from an alternator due to a number of reasons including voltage control, BMS shutdown and the high chance of causing alternator damage when the current being requested is greater than what the cooling is applicable for.
There's a catamaran manufacturer that I keep having this conversation with, and I keep getting calls from their external repairmen telling me that a lot of kit needs fixing after when they don't do what I advise.
-Ben
What if a current limiter is added to the battery?
Depending on how the current limiter works, then it may well be a sensible and safe option.
There are not many simple current limiting items out there.
Best,
Ben
I can charge my lithiums @ 200a direct from alternator with no issues. If you use the right battery then its no issues. The quality of the BMS and Cell management system goes a long way towards increasing performance.
Hi MOS,
In our tests with a variety of batteries and BMS, and indeed tests that have been held out by our major competitor, we find that the incredibly low internal resistance and ease to charge a lithium battery off of an alternator is rarely without problems. I believe our blue competitors video ended with an alternator very much smoking.
That said; we do have customers who simply use our non current limiting charge systems on lithium and rarely complain; so perhaps we are being overly cautious, but that's the side I'd rather be on than recommending a potentially risky setup.
-Ben
@@SterlingPowerLtd The blue competitor used a battery with no BMS at all and of course it will fry the Alternator. Keep watching and they use a BMS later in the video with no issues. Ive been using alternators in 200 series, Hilux, Patrol, Dmax, 100 series, Hiace and many more and not a single issue. I use a Brushless, Sealed, Watercooled 200a unit with no issues in my own car. Not many lithium batteries can be charged this way but they are on the market and cheaper than the "green, Orange or Red" ones and have a 200a BMS so discharge and charge rates are much higher.
@@VEOPengineering Interesting- I'll have to rewatch! Most BMS that I've come into contact with generally just facilitate the lithium charge and then put the lithium drain and demand directly onto the alternator - until high current causes a BMS disconnect.
I'll be sure to do continue my research and testing, as I have to do with everything in this market, I merely like to play things safe when representing the company :)
-Ben
@@SterlingPowerLtd I uploaded a video for you to look at.
@@VEOPengineering Hi Toyo;
Thanks for that video! It was genuinely an interesting watch. I find the very variable voltage and current interesting, you may benefit from an alternator regulator, but the fact that the alternator never really seems to rise above that comfortable 51' mark is quite fascinating,
The M/D is doing more battery tests today, largely comparing the market. Perhaps we've been overly cautious so far, but I'd have to do more tests before I can be certain.
Thank you for your knowledge though! It is always good to be challenged by a new view, pushes us to continue our research.
Great educational video and thank you for answering my questions for project.
What a great video 👏 Thanks
Why, during testing, did you put load on the lithium battery ? Most rv driving have no load on the lithium battery. Would not having a load decrease the damage to the alternator ?
He's trying to illustrate what would happen if you have a deeply discharged battery/s and the alternator is running flat out for hours. It will kill it.
Remember 100amps over and hour is 100ah.
The lager the bank the more charge is required.
There are many factors not being mentioned here depending on the application. I don't know of ANY scenario where your lithium house batteries (assuming we are talking about RV/Travel trailer/5th Wheel) are going to be 3 feet from your alternator connected with what, 6 awg wire!? a boat maybe? In a typical, real world setup, considering you are trailering something, there could be anywhere from 15 feet to over 20 feet between the alternator and the batteries AND, with the connection being through the 7 pin connector, is running over like 16 awg wire. You aren't getting anywhere near the kind of current you are demonstrating in your bench example. Maybe do another test using a real world example? I would assume you would agree that distance and wire gauge have a major impact on the current over a line.
Hi-
On the one hand, you're broadly correct about what you would see in that case.
On the other hand, you're using a cable (one of the leading causes of electrical based fires on vehicles) as a resistor to drop voltage and to drop available current flow accordingly.
We're not particularly fans of intentionally using insufficient cabling as a way to current limit because of the massive risk to vehicle, vessel and life- not to mention the lack of ability to get insurance or to actually meet the warranty needs of your equipment.
HI, i have heard of the alternator connected to an AGM battery and the AGM acts as a 'reserve tank', the AGM then passes through a 500amp stinger regulator to a 100AH lithium phosphate battery (without any issues). Does that sound feasible to you? I'm no expert.....Thanks
Hi Shaz,
Without a method of limiting the current being demanded from the lithium, in this system, I cannot recommend it on behalf of Sterling Power.
Lithium batteries have incredibly low internal resistances and as such will request all available power, readily. This is the problem. If 300A of charge is available to the battery, it will request it. This often leads to the BMS tripping out to 0V, refusing charge, or overworking the alternator.
It will likely be fine for a period of time, but I cannot recommend it on behalf of the company.
-Ben
@@SterlingPowerLtd Thank you for the response and for edcating me on this...
So I have an 07 Prius I want to get rid of the lead batteries and put in lithium do I need to worry about the alternator or something
Hi there,
Are you looking to replace the starter battery or your rear batteries? Lithium interacting with an alternator directly is always going to be something to be aware of, as you could damage the alternator or you could very well damage the lithium.
B
@@SterlingPowerLtd exactly, i am thinking about both? However after looking into this more not sure. I want to start producing a lithium battery pack for the Prius gen2 that is affordable.
@@lookingupwards8652 Hi there,
Generally lead acid is perfect for a starter battery - then if you would like a lithium bank in the rear to run your appliances and equipment off of, we would utilise a battery to battery charger to facilitate charge from your alternator side to your lithium side safely.
Ok but by not measuring the temperature while loading "standard" lead acid batteries how do we know this is not a normal functionning temperature for an alternator ? Most probably you did that however.
We did not run that in this test because lead acid/alternator interactions are already extremely well known and documented.
Lead acid batteries paired with an inverter can cause alternators to overheat, but this is extremely rare, whereas the high draw from lithium is essentially inherent in its makeup.
Lead acid batteries have their own noticeable inefficiency and internal resistance, this resistance can be overcome by elevating voltage beyond that which the manufacturers recommend, but generally they will only draw a very modest flow. Lithium due to its very low internal resistance will accept current as readily as it is available.
Yes, were we doing this as part of a thesis we should have likely covered a control experiment side-by-side, but our intention with this test was to show the effects of lithium on an alternator in an unmanaged situation, versus the effects of various battery chemistries on alternators.
ShOcK & AWE. The best demo ever :O) It's true what people are saying- Sterling Power RoCkS! Cheers from So.CA.USA 3rd House On the Left.
3rd on the left? We'll come by for drinks!
do you have a product that can take two alternators two start batteries and a 650 am^service just had a customer ask for an upgrade on a lagoon catamaran and found your youtube, I already installed your alternator to battery charger on a monohull and it was easy and works perfect ! thank you !
Depends on the alternators and depends on what we're trying to charge in the service bank.
If you can give me more information regarding A) Alternator rating and B) If the service bank is going to be lithium, I can advise from there.
B
@@SterlingPowerLtd Thank you for the swift answer the boat is a lagoon 50 equipped with 2X D75 Volvo diesels I believe they are 90 amps alternators and definitively going lithium as we need to change the service battery bank, boat has 3X140 AMP acid as service, plus two starter batterie for the engines, boat is also equipped with a 11KW generator with a viltron multi 2500 watt charger inverter, the generator is a stand alone I would not change it starting battery for a lithium, but I would like to know if you have a solution that is safe and easy let's just assume the owner is not a technical person, and I would like to build him and hopefully the next catamarans a better system; one that can eliminate the generator, have a nice day !
@@teknotikpointbiz Hi Tekno! I've had a lot of consultations with various catamaran builders, owners and fitters recently so this should roll of my mind fairly easily.
The first thing we need to control is how much current your lithium bank is going to demand from your alternators. If we do not limit the current we will see your alternators gradually degrade due to being ran at 100% continuously while not having to run at the correct RPM to cool itself.
The solution is to have each alternator feed onto a designated starter battery, then to have a BB1260 coming off of each starter battery, then go to your leisure bank. The BB1260 is a current limiting charger so will never request more than ~60A on the input.
Two BB1260s will offer you with ~100A at 14.4V to your lithium bank while keeping both of your alternators within a safe operating range.
Does that sound suitable?
@@SterlingPowerLtd not only suitable , awesome and fast plus not too expensive , easy to install too !, so thank you very much !!! I am looking for the bb1260 here in Montreal you seem to have a distributor, to quote my customer ! if we go ahead I'll keep in touch ! really great to have someone answer so fast ! but now in the case I have to do it on a Saba 50 same setup except the starboard engine is started by the house bank usually would you recommend the same setup as adding a starter battery ? merci et bonne journée !
@@teknotikpointbiz Hi Tekno,
Thought this would pop up! Yes; typically we find that catamarans have two alternators but only one side with a starter battery. This would normally pose a problem but Sterling has a solution.
The Alternator Linearisation Device (ALD) essentially acts like a starter battery as far as the BB is concerned. In instances where a starter battery is not present an ALD can act in a similar way to clean up an alternator output. Instead of going Alternator -> Starter Batt -> BB -> Lithium, it goes Alternator -> ALD -> BB -> Lithium.
Hopefully that helps!
-B
I think it is difficult to generalise the statements made in this video. My boat engine has a 115A alternator and that alternator charges a 70AH AGM for the engine and 3x 105 AH LiFePo4 for the board battery (supplies all other electric sources). I've used this setup for 4 years and have not had any problems. Yes, the alternator heats up to 100 degree C and remains on that level. The charging current drops from 95A to 60A within 15 minutes due the alternator getting warm. Bottom Line: if you have the right alternator (power, heat controlled charging) and the right batteries you can do without a B2B charger.
Hello SailingMan,
I find it hard to just stick to that statement however. Many boats have insufficient cooling to the alternator and many alternators are not designed to work to their actual specifications. Simply telling someone that their alternator is insufficient rarely solves the problem, so we have worked on making a solution that will always pose a solution and that which stops the alternator getting hot in the first place. It's been pretty successful so far and a number of lithium manufacturers recommend its use directly to make sure the system works.
@@SterlingPowerLtd I would agree that a booster or B2B charger is a safe bet. However, if an alternator is able to deliver more Amps, the B2B would not leverage the full potential of the set up. I think the bottom line is that you need to understand WHEN a B2B charger is required and when you can do without it.
@@sailingman143 Correct, but many lithium companies (and alternator companies, honestly) don't want you to use the full potential, as it's unlikely everything was meant to run at that level continuously.
We're working on systems that will integrate with the onboard CAN that most vehicles now have and will allow us to milk systems to their limit. There's been a number of cases where even an alternator running at 60% of its rating gets hot enough to break down- obviously that's one of the extremes but it's something we try to avoid ever going near in the first place.
Obviously there are systems out there that don't integrate our kit- but many do and it seems to be something that is growing as time and requirements develop.
sailingman I agree. Friends of mine busses are running just fine with the secondary alternator...no external regulator/dc/dc charger
I have a 220-amp alternator and a 230-ah lithium battery, do I NEED a dc to dc charger ?
Yes, otherwise your alternator will likely be overheating, particularly at low RPM.
You'll also run into issues if
1) Your lithium battery is ever full (alternators on zero capacity circuits can be destructive)
2) Your lithium battery fills during charge and the BMS turns the charge circuit off (potential for voltage spike)
3) Lithium may not be able to be woken up by an alternator, particularly if it requires an excitation voltage.
I wouldn't call a Bosch alternator a 10/10.. Test a C.E. Niehoff alternator and see how they do.
I'll forward this to some of the hardware team, see what they say!
Ben
Can't we just use a current limiter btwn alternator and lithium battery ? What is the disadvantages of it with compare to B2B charger? Thanks.
Hi PLT-
You can indeed!
Disadvantage of some current limiters is that they A) Do not isolate both sides from one another fully, and B) Doesn't actually end up either providing a constantly active load or C) Boost/control the voltage to a sufficient level to help the batteries charge.
Problem with A) is that your lithium batteries may trickle to elsewhere in the circuit as their rest voltage is rather high. B) Could prove to be an issue if your BMS ever shuts off. C) could delay your optimum charge time (with that current), or, if the Voltage is temporarily too high, trip your BMS.
Hope that helps,
Instead of a dc to dc charger why can't you use a simple current limiting diode say 50A
Hi Robert;
Beyond it not being covered by most battery warranties and likely not being able to ensure the voltage going to the batteries is actually suitable for the charge- it also is just against the ideals of protection that the system is looking for.
The lithium will still be demanding a draw and for as long as the diode is present on the circuit, one of a few things can happen.
1) The diode gets blindingly hot and the voltage-drop actually stops the current flow, but the diode might be flammable
2) It's possible that if the draw is still high but the diode is dissipating the 'excess' as heat, that neither the alternator nor the diode are protected from being overworked.
forum.allaboutcircuits.com/threads/current-limiting-in-battery-charging-circuit.126240/
electronics.stackexchange.com/questions/415563/lithium-ion-battery-charging-problem
Your options are either control the field (and thus the provision from the alternator) directly, or use a system like a DC/DC charger to create two independent circuits (IN and OUT) so as to properly and safely taper the current.
Sorry but I must call foul. Nothing that you said was not true but (and this is a big but) you left out a lot of information because it does not sell your Dc2DC charger. You are correct that an internally regulated alternator will get cooked when charging LFP especially at lower rpms. What you left out is that it is completely safe to charge the LFP pack from a directly connected alternator that has external regulation which monitors the alternator temperature. The goal is still to limit the current but that is done based on the alternator temperature.
A very big dc3dc charger will only put out 40A. On my boat, I have a 160A alternator and can put out 120A and not go above a case temperature of 90ºC at cruise rpms. If I run the engine slower, the thermostat will cycle the alternator off as needed to allow it to cool down.
Hello Hayden,
A couple of things I'd note.
1) It depends on how the alternator regulator actually responds when an alternator reaches the critical temperature. If the regulator can interrupt the field line and has some means of current control- great. If the regulator merely turns off (therein likely resorting to the internal regulator), it could continue charging at a high current and therein still overheating. If the regulator bucks the voltage down- this is likely suitable enough to stop current flow, unless the lithium battery is particularly empty or if the lithium battery has a large load on it.
2) It also depends on how we're recording said alternator temperature. CAN readings from the core (if measured) would be relevant. Readings from the chassis can be delayed sufficiently to lead to the alternator core still getting hot enough to be damaged before the chassis temperature sensor signals a response from the regulator.
3) I have not actually seen much written, videod or discussed about actual current limiting of alternators. It's written in passing in some item descriptions (of some regulators), but it is not yet written as an exception in the warranty of many lithium batteries or alternators. Whether this is because lithium and alternator companies are slow to respond, or because they do not believe it is suitable is unclear.
4) A 40A BB is not particularly large. 40A would be the second smallest of our newest Saturn range, where we have items from 25A up to 200A at 12V. The 120A BB would suit you perfectly.
@@SterlingPowerLtd Thanks for the reply.
1. None of the external regulated alternators that I have experience with have any form of internal regulation. They have all been B-type (positive field wire) so if the regulator is not working neither is the alternator. That is a safety issue because with an A-type, any problem with a short in the field wire would cause an unregulated alternator runaway.
2. The alternator temperature is taken from a stud on the case if one is provided by the mfr or from the hottest location on the case per a thermal camera if available. If neither of those are available, run the cold alternator for 30-seconds, then shut off and feel for the place that gets warm first. I used this method and then installed the probe in thermal paste and held it in place with large hose clamp with insulation over the top of the probe. It is true that the innards are much hotter than the case but the manufactures of these alternators give safe limits for the case temperature which are usually around 100ºC
3. There are many sources of info on external regulation for charging LFP battery banks. They are available from Balmar, Electromaax, Wakespeed and others. Wakespeed can even use power output from the ECU or engine RPM to reduce the output so that big alternators do not overwhelm small engines. Here is a video to a 40hour deep dive into external regulation. ua-cam.com/video/3uWWysz4blw/v-deo.html
4. Just using a large DC2DC chargers would not limit the temperature of the alternator. In my case, if I need to motor at less than cruise speed, my alternator will still get too hot even when limited to 120A. For a system that is designed to charge large LFP banks, I prefer to have a smart regulator that sets the output based on the ability of the alternator within its limits.
@@haydenwatson7987 Hi Hayden!
1) yes; correct. There are both pos and negative field control regulators available, mind. It does depend on how it shuts down, and indeed what it defaults to in said state. Our opinion is that it's better to not let an alternator get hot in the first place rather than to respond to an alternator as it gets hot.
2) Sensible method, though I've seen alternators sustain damage from even correctly 'temperature sensed' apparatus. Most strikingly is a catamaran manufacturer that had both alternators sustain damage in the form of melting internal solder. When said solder dried the alternator did not spin. It depends how critically hot the core can get versus the chassis and how the items respond to said heat.
3) The Wakespeed (WS500, off the top of my head) is the only unit I'm aware of that claims it can current limit and can actually feasibly do so. Thank you for the video all the same.
4) Correct- however a correctly rated BB system would not overheat an alternator even at idle- and in the situation where other loads are also competing for the BB's input (and potentially then bringing the alternator to run harder than expected) the BB will automatically downrate.
Hope all the points come across as I intend them to!
Very interesting, my 60a Sterling B2B gets too hot in summer charging 345a/hr of lead acid, in my motorhome. I am adding another to reduce the loads and temps and reduce charging times. Fine in winter.
Hi Simon,
That is quite a bank for it to fill but I hope the fan on it is sufficient to keep it running throughout! So long as it is in a sufficiently ventilated area the fan cooling should help itself run continually at an expected rating.
A second BB will definitely take some of the stress off the first one, though, so long as your alternator is comfortable with this combined current!
If you need any assistance, give us a shout,
B
Actually, it is quite a straightforward solution, this is needed. All we need to do is install a heat sensor on one of the components, that heat up the first. Using a simple op-amp circuit, the reading from the heat sensor will disconnect exciter current to the rotor, until the temperature comes back down, within allowable level and then the exciter current is switched back ON. Anybody with a reasonable experience in Electronics, can put this circuit together.
Do a test like in a real world scenario .Most people would have a lead acid battery in parallel. That would take the load off the alternator with it charging the lithium & not drawing too much current itself off the alternator. PS time to go back to school my friend!
Hi Andy;
A lead acid battery in parallel is not, on its own, a protection against high current. It can be a protection against voltage spikes, but it can add additional dangers of its own.
A lead acid battery in parallel will not take the load off the alternator at all; there is still capacity on the circuit to be filled. It is now lithium (high draw) + lead acid (low draw). The low draw does not eliminate the presence of a lithium.
@@SterlingPowerLtd But the lead acid battery at full charge will pump out power to charge the lithium & help out the alternator. Check it out for yourself with an amp meter?
@@andyb6120 That's not how it works in my experience or in my measurements. Because lithium rests at a higher voltage than lead acid throughout much of its operating cycle (A 40% SOC Lithium is ~12.8V at rest, a 100% lead acid is about 12.8V at rest) there is simply no logical way for a lead acid battery to be able to support charging a lithium battery over 40%.
Voltage can only 'flow' from itself downwards. IE, a 12.0V charge voltage will not charge a lead acid battery effectively, because a lead acid battery at above 12.0V will draw nothing.
Further, flowing from a lead acid battery into a lithium battery can actually be dangerous. In the event that you do put a 12.8V lead acid battery onto a
If you look a independent external alternator regulator with some logic and temperature compensation.
Hi Pascal,
I believe some alternator regulators are being introduced into the market that have current limiting, or at least being theoried to have current limiting, but a regular alternator regulator will not be sufficient, even with a temperature sensor. Some clients and customers are happy to go ahead without them but I must always warn them to be aware of potential alternator degradation.
B
can he be saying this to sell something?) my alternator is almost 300 amp so no thanks
Even with a 300A alternator, it's sensible to have a correctly current limited system. We've done nothing untoward in this system to force this response. There's a reason why every single lithium manufacturer recommends a correctly equipped system.
If your lithium battery bank has a relatively low charge rate (some Lithium batteries have a charge C rating of as low as 0.1C- though thankfully this is very rare these days), specifically a charge rate underneath what the alternator is rated to, you'll likely see no charge going into the battery bank at all.
IE, you'll see the alternator engage, provide up to their max rating very quickly (due to the low internal resistance of lithium), exceed the C rating dictated by the BMS, and the BMS turns off the charge input circuit.
Alternatively, if the C rating is above what the alternator can provide, you'll see the alternator running at max yield for prolonged periods (particularly on a well discharged battery), and when operating at a low RPM but high output, you risk seeing serious degradation or damage at the alternator.
We'd rather you have a succinct, correct system that runs for a long time than having to change the system (or replace the alternator..) shortly after.
We have clients operating on twin 400A alternator truck systems and twin 300A catamarans that utilise our items with no issues.
This is interesting to me.
What is the best way to current limit a standard alternator to make it reliably charge a lifepo4 setup?
Hi Jade,
We believe the best way of doing this is with the alternator going directly to a dedicated lead acid battery as a buffer, most starter batteries on systems are sufficient for this, and then using battery to battery chargers to provide the perfect maintained charge to a target lithium bank.
-Ben
@@SterlingPowerLtd Thanks Ben.
Yeh I'm doing that with my house battery system.
There is a company here in Oz that makes a lifepo4 battery that is suitable for winching/ starting and can be installed under the bonnet.
They are a reputable manufacturer and the batteries are definitely not cheap, so I have no reason to doubt their claim
My concern was, due to lifepo4 having such low resistance to charge, and with a second battery also running via DC to DC charging, plus the usual other vehicle loads, perhaps the alternator might burn out?
Because the battery might be capable of drawing 100 amps continually and it was my belief that alternators don't like doing this.
I wanted to take an alternator and then current limit it to say 75% or so, so that even if it is pumping this current in for a long period of time, it is still not running continuously at full capacity.
Does this make sense?
@@thewhiteoxoverland Hi again,
That's more or less exactly what we've found, thus why we try to keep lithium and the alternator away from interacting with each other. Lead acid is great as a starter battery, great at cranking and doesn't put unnecessary drain on the alternator- and never is at risk of just disconnecting if a situation goes out of what it prefers. Lithium as a starter can be done, I know it can be done because we've done it for the M/D's tractor, but it's never something I'd advise to a client.
Alternator -> Lead acid starter -> Battery to battery chargers -> Lithium bank. That's the only way we recommend
So couldn't an additional 12v high powered fan keep the alternator cool?
Hello Geoff,
Very unlikely. It's the internal temperature that is rising at an incredible rate and even a significantly increased airflow on the outside of the alternator will only lead to a moderate-to-small increase on cooling on the inside.
Alternators are not made to run at their rating for prolonged periods, and often do not run at the correct RPM for cooling when running on lithium batteries.
Battery to battery chargers are really the only option we and many other lithium battery manufacturers recommend.
-Ben
I've successfully added a fan to a small case hairpin alternator at 160amps, and a 100ah headway lithium. I pull 1000 amps burst power for car audio, my alternator duty cycle is indeed 100% and beyond. 30k miles so far, major abuse on hot days with the AC full tilt, and ticking right along nicely.
I mounted a high RPM, high flow 80mm delta at 84cfm to the rear of the case, where the rectifier is. It's quite a performer, and just a plain, stock Toyota small case hairpin. Powers a 10,000 watt stereo setup, intermittently, of course, till the batteries are low. Then I take a break, and that single alt charges the bank back up with the AC going for a an hour or so, and do it all over, in the sun, peak heat of Summer even, over and over. Try it out, you may be surprised at the results!
Thank you. Very interesting video. I'm looking into lithium charging from a smart alternator an a new van ( using a DC to DC charger). With a particular interest for tick over speeds. Does a smart alternator controller look after the health of the alternator at low speeds better than the traditional alternator controller? Many thanks
Hello Jay,
No, not that anyone is aware of. Smart alternators are even worse with lithium (if without a DC/DC charger) because smart alternators, to minimise the potential charge time, normally operate at much higher voltages than we would otherwise want going onto our batteries - which in the situation of a lithium with an integrated BMS would often just mean the BMS disallows further charge - meaning you're getting no charge through at all.
DC to DC charger will always be our recommendation for lithium and alternator systems.
@@SterlingPowerLtd Many thanks for your reply. Just as a matter of interest, I have noticed that there is some sort of controller on my euro 6 van negative battery terminal. This backs up what you say about using an earth wire from the charger all the way to the vehicle battery. Using the chassis for the earth connection is likely to upset the operation of a smart alternator
@@jaybee258jb Hello,
We actually recommend using a common and direct negative for a different reason. When boosting voltage there is some current that runs down the negative line. Passing current through the chassis of the vehicle is horribly inefficient, as I'm sure you can imagine, and can lead to unit damage.
Good day, I have just bought an alternator to battery charger (Sterling AB12160) hoping to be able to charge lithium batteries, I note with regret that this is not the case. Are there no solutions? do I really have to go to a B2B charger? Thanks for your answer.
Or get some LiFePo4 batteries with proper programmable BMS through which to limit the charging current.
Hi Candro,
I'm not aware of any BMS that can actually taper and limit current at this point in time. They simply disable the input MOSFETs if the current is exceeded. This means the charge rate is 0, not whatever you set the limit to.
Thus why many lithium manufacturers recommend having a properly lithium suitable circuit.
Best,
Ben
@@SterlingPowerLtd I was thinking that as per charge controllers, there could be a way to limit the charging current directly from the BMS.("closest thing" to the battery terminals and the one who "protect them"). Anyway, I am bitter due to the fact that BMS app (freshly installed) that I have, has few drawbacks. I will look for the available features. Thanks!
@@candro5510Hi Candro,
Ultimately, in the long term, it's possible. There are batteries on the market with integrated DC/DC chargers that actually do similar behaviour- but I am not aware of any BMS that simply limits current. IE making 14V 200A available to the BMS, it only draws 50A.
Ultimately most BMS primary features are distributing the charge to the cells equally and offering protection. The significantly elevated cost of having a current limiting charge circuit would render many batteries far more expensive - rather than just having a lithium suitable system.
All BMS I've seen so far simply turn off the input when charge current parameters are exceeded. They may have a timer associated or not, but I'm not aware of any that actually taper current.
Can you clarify something for me? Given you require a Dc to Dc charger and the donor Dc source is normally a lead acid starter battery then is it the case the lead acid needs high cranking amps CCA to optimise the capability to charge lithium batteries quickly?
I understand the Dc to Dc charger if a smart one will optimise the charging process and give undervoltage protection to the donor but I can't seem to find advice on donor battery choice, obviously a 150ah donor battery will have better capacity than a 110ah etc but to optimise time charging in shortest possible time there's no good having a lithium battery accepting 90 amps if the current drain on the donor can't give it without damaging the donor battery. (Which the charger won't allow anyway).
So is the choice of donor battery all about Ah capacity or does CCA factor in to charge times and donor battery protection (i.e not wanting to put the donor battery out of condition over several months)?
Hi Ray,
The discharge capabilities of the lead acid starter battery is largely irrelevant. Its purpose in the circuit is not to power the BB, but to stabilise the alternator output. Without any sort of accumulator on the input the alternator voltage will be erratic at best and destructive at worst.
The lead acid battery does not provide power to the BB- it just holds the alternator steady. The BB draws power directly from the alternator VIA the studs of the starter. Nothing is pulled from the starter itself.
You don't even need that sort of massive input battery. Systems as small as 60Ah have been suitable.
Ben
That's why you ALWAYS choose HALF amps for li on or lipo .
60 Amps lead acid baterry is equal to about 30 amps and less for lipo
Lipo are amp suckers due to.less resistance
Why did you not tell the battery manufacturer and model or at least give the specifications on it. I’m pretty sure that battery has no current limiting or controls in it. You should tell the whole story, not just the parts you want to push. Why did you not give the RPMs you were running the alternator? At a very slow engine idle of 500rpm, the alternator will be at 1250 rpm.
Hello Kevin,
The battery was an AL12100 with the over-current shutdown disabled.
As far as I am aware, there is not a single lithium battery on the market that has current limiting as part of the BMS. They have over-current shutdowns, that cause the battery to turn off if the current is exceeded. Had we not turned the protections off, the battery would not have taken any charge at all. Had we had multiple batteries in a larger battery bank, the protections would not have been exceeded in the first place.
Our blue competitors have done the same test, their alternator started smoking.
At a higher RPM, cooling will be increased to the alternator, so long as decent cooling is even available, but this is not always possible.
What if you don't have a alternator but a gear diven, oil cooled, brushless DC generator and a external voltage regulator, my dc generator is a Delco Remy 225 amp. What would you recommend for charging lithium batteries
Hi James-
Hard to say for sure as it's not something I've had years of experience recommending on, compared to alternators, though I'd imagine it's a similar case. Most items were not historically designed to run at their limits continuously and so will likely benefit from the current limiting control that DC/DC chargers can provide.
Talking to the manufacturer would be the first step, as they can probably recommend RE: limitations and capabilities. If they think overheating is a risk, going down the route of a DC/DC charger would be our recommendation.
Ben
I have a 125 amp alternator on a diesel pickup that has no load to speak of..no electric windows, seats or AC and LED lights so very little draw BUT I am putting in a 12 volt AC split which is rated at 60-80 amps depending on how cold one wants if the AC split is only running while driving can I just run it off the main battery to a lead battery with a solenoid so it cannot run while truck is off? Or would it still need the DC to DC charger...it seems it would be fine since at max it would be about 80% of alternator capacity but want to make sure :-) and NOT burn up my alternator
Hello Fedorico,
Ideally we'd be running the split off of a leisure battery bank at the rear, so as to minimise the load on the starter system and minimise the possibility of you being left with a drained starter battery.
That said, assuming you have a system which only engages when the ignition is on and the alternator is running, the alternator should cover those loads fine and happily.
Ben
I have a 2000 F350 with factory wiring going to a camper containing 2 - 100ah lithium battery's. Won't the factory 12 or 14Gauge wire limit the alternator output to the lithium batterys in the camper?
Hi Bill,
I probably wouldn't advise using one of the primary sources of onboard fire (the cabling) as a resistor when charging lithium banks from an alternator.
If your lithium batteries are low, or providing to a load at the same time, and your alternator is at a decent RPM, even with massive volt-drop between the alternator circuit and the lithium circuit you'd see a lot of current flow.. and if that cable gets too hot or degrades over time, you have a threat to life onboard.
We'd recommend current limiting via DC/DC chargers in your case.
Ben
Ok.
Why not just reduce the field current?
Many regulators don't have that capability- there are some exceptions, but they certainly were not available at the time. There also does not appear to be much actual noted work regarding them making lithium batteries and alternators suitable for one another.
If we end up testing one in a setting such as this, I'm sure a video will follow.
question is , why are you charging a dead lithium with your alternator ? in a car you would never see this unless you ran ur lithium dead , and then it shouldn't start ur car and you would be forced to use a PSU / charger ..... am i missing something ?
Hi Mazda;
Most lithium batteries are not in a starter battery position, if they were they would have to be rated for the cranking discharge rate (which would often require more premium cells) and the performance you would get from one in a starter battery position vs a lead acid would be negligible.
As such, we often advise (when advising RE: batteries) lithium in house battery positions, thus battery banks that are likely to see fairly sustained and continuous use. In campervans or boats that are not plugged in overnight and don't want to run a maintaining engine overnight we can see discharge from those batteries for the next day.
Many people like the ability to charge their batteries from their alternator when running, and thus when the fairly drained lithium bank is connected to the alternator, we would see the alternator output spike to maximum output until the batteries were full.
We see this with one of our fitters now. They are using a non current limiting charger on some fairly premium boats. Works great for a while, but they often need an alternator 'update' after a few months or a year of use.
Hope that helps;
Ben
@@SterlingPowerLtd i see , I use them as starter batteries and high power audio where we dont discharge them while the vehicle is not maintaining them and I guess we do use more premium cells . Normally for a system using batteries that get discharged we use a regulator with load control built in so the alternator slowly applies its amperage and it does not full tilt to begin with . Also due to the low c rate on non premium cells they prefer to be charged slower .
@@mazda2284 Hi Mazda;
Correct regarding the low C rating on many cells; exactly why we need a current limiting charger in many cases. This is the direction that basically all of the power distribution companies are going down the route of, and the same route that many of the lithium battery manufacturers actively recommend for both alternator and battery safety.
Is there a simple device that I can put between the alternator and a Li-on battery to protect the alternator?
Hi John-
At present? Other than a battery to battery charger (IE, a current limiting charger), not really.
We're working on a current limiting alternator regulator- but we're still finalising the code, so it's a minimum of 6 months away.
Ben
@@ThreeFineWonders Hi Charborne;
In theory it would make alternator to lithium direct charge safe and as such thus be a replacement of the BB in that sense, but it would miss out on a lot of the other benefits integral to the BB.
Alternator regulators are often not as intelligent and as such you may not be getting the most perfect charge pattern which may affect charge time, you may also see voltages vary slightly more than you would through a BB. If your battery bank is happy with a slight range of voltages and your main concern is protecting your high powered alternator, then the current limiting alternator regulator will be ideal.
I doubt the current limiting alternator regulator will be cheaper than a BB, but I've got no true idea of the cost to public as of this moment.
Other, higher power BBs are in the works actively.
-Ben
Yeah, a dc to dc charger.
@@HWR1JZ are you suggesting to put a DC to DC charger between the alternator and the lithium battery? What is the difference between a DC to DC charger and a battery to battery charger?
So, add a brick to your RV for a high idle kit? 😃
Can you just use a ProReg-DW to control the alternator. Instead of a B2B charger.
Hi Terry,
While our engineers are working on a newer range of alternator regulators- our current regulators are not current limiting.
If you're running lithium you need current limiting otherwise your alternator, as shown, gets pretty uncomfortably warm. BBs are our recommendation at present until units currently in design and prototyping reach the public market.
Cheers!
B
But doesn't the ProReg-dw have a temp sensor for the alternator and shut it off if it gets to hot?
@@terryscully3272 Temperature sensing is done off of the studs of the unit rather than any internal thermometer to keep an eye on the coil. By the time the studs get hot, because the coil gets so hot so rapidly, damage could have already been done. This also doesn't solve the issue of maximum current going down cable. This could blow fuses and burn out cables if you weren't prepared for this level of current draw. If you were prepared for the current draw it might be meaningless anyway as most lithium BMS' actually also have a current shut-off parameter. Once it gets slammed with an uncomfortable current the whole BMS will disconnect and you now have a paperweight at zero volts.
Further, would you rather a unit that keeps charge continually and at a safe rate or would you want something that disconnects unexpectedly?
I understand your wishes, genuinely, but with the current regulator it just isn't an option.
Down the line we have plans for a regulator that can solve these issues, but that's a story for another video, when it's ready.
If my travel trailer has one, 100 Ah lithium iron phosphate battery hooked through the 7 pin connector of my tow vehicle, won’t the small wire itself limit the flow of current to the trailer lithium battery thereby protect the alternator?
Hello Stuart,
I don't think I'd ever recommend somebody to use thin cable as a means of limiting current. It sounds like a one-way route to hot cable and a potential fire-hazard..!
-B
Wow an interesting and very telling demonstration. I have just ordered some lithiums for our boat so am currently looking into the best way to charge of the engine
Hi Boatingtube,
While we are actively developing an expanded BB range and we do have other current limiting methods in the pipe-line, at present our best and incredibly highly recommended method of current limiting would be to go down a battery to battery charger route.
Four stage charging, customisable voltage output, current limiting- can't really go wrong.
That said, as our BBs can be ran into parallel you do run the risk of just having the opportunity to run your alternator at 100% anyway, so never have a BB setup that is more powerful than 80% of the rating of your alternator.
If you need any further clarification, ask away
B
@@SterlingPowerLtd thanks for the reply, there is definitely a gap in the market in this space as none of the big vendors have a perfect solution, paralleling up B2B's is a solution but becomes costly and a little cumbersome to install. I would love to see Sterling add some additional capabilities to update your alternator regulator to support Lithium's and adjust the field based on temperature sensor like the Balmar but at a less ridiculous price and supporting negative field alternators for us here in Europe.
@@Boatingtube NEGATIVE FIELD?? Why on God's earth would you tolerate such ridiculousness? Force your suppliers to STOP creating NEGATIVE FIELD PRODUCTS. PATHETIC.
@@Boatingtube I'm fully aware!
Your alternator regulator ideas have been thoroughly thought of and is on a production pipeline but has been put behind the development of some other products. I don't know why, particularly, but alas I'm not in charge!
Adjusting on temperature really isn't a perfect method. The idea we have in mind is far more comfortable but I'm not really allowed to talk about it publicly because I know for a fact that some competitors like to watch development, too. :)
Watch and see. We have a few things that I want out and I'll be sure to push them heavily, both on the UA-cam front and on the mail front, as soon as we have them good to sale.
B
Interesting. We have the Sterling Alternator to Battery Charger with AGM batteries and two banks.
Replacing the AGM bank with Lithium. The Sterling is a few years old and cannot be configured to Lithium.
How do I keep the current setup and add a product, e g a battery to battery charger, to the current config to save the alternator?
We got both an alternator and an old battery charger connected to the In ports in the Sterling. Can Lithium also wreck the battery charger?
There are no engine rooms at 100 degc
You'd certainly hope not. If there is, it's no longer an engine room.
Perhaps hyperbole- who knows, cannot speak for the M/D myself!
Perhapse a cheap and dirty solution is to use a current limiting large resistor inline to the lithium charge circuit. Not efficient but it would work.
Cheap and dirty may do it- but that's not something we could ever necessarily recommend..
It'd be crude, could lead to uncomfortable heat generation, and the naturally varying input (Current et voltage) could lead to complications in getting everything operating quite how you want it to.
Or- you could get a battery to battery charger.... :)
People have been experimenting with it on Will Prowse's forum (DIY SOlar). Most folks with relays are introducing resistance unknowingly by running the NEG return through the chassis. This typically knocks charge acceptance down to about 0.32C.
Yes!! My Thor Tranquility is doing this; I think...
Thor and Tranquility sound like antonyms to me..!
Let us know if there's anything you need a hand with.
How about limiting the current with a 1/2 ohm power resistor? Given the difference between alternator ~14v and discharged battery ~10v the max current would be 16amp (4v/0.25ohm) which would reduce load on the alternator both at max discharge and when the BMS cuts off charging at the top.
Would that work?
Hello Rani,
Assuming everything is constant then yes, this would be fine. But the variability in charge rate, alternator output voltage, battery voltage-
The calculations for the majority of the period would just not be correct.
We believe thus far that a DC/DC charger is the best way for both protecting the alternator and the lithium system, and we generally find that vehicle and boat builders and lithium suppliers all seem to agree with us there, too.
@@SterlingPowerLtd Hey - thanks for the reply. Assuming the assumption that the much voltage delta is less than 5v, this would solve both over-stressing the alternator and the cut-off event when the battery is full and the bms shuts off charging. While I agree DC-to-DC is a better solution sometimes a $100-150 cost (charger + cables+...) is an issue and sometimes space (eg., on class B vans or truck camper) does not allow for DC-to-DC charger. My question here is not if it's the perfect solution or if DC-to-DC is better, my question is if it has any downsides - apart from slower charging (especially as lithium reaches max voltage - in which case it's probably better for charging to be slower at this stage) - does it have any risk or would it solve the alternator issue?
@@ranig2848 I frankly would not know without trying. I believe the only definitive option to protect the alternator is to limit the current it can draw in the first place.
A resistor across point A to point B may deter rate of charge by limiting the differential between the two- but with the incredibly low resistance inherent with lithium I really cannot guarantee that this would still protect the alternator.
Our alternator to battery charger (non current limiting) applies a resistive load between the alternator input and the main output battery whenever the unit is in an alarm/fail state (over temp, over-alternator temp etc), and if the leisure battery is still lower than the resistor-lowered-voltage of the alternator feed, you're still going to see current in motion. If the alternator is already getting hot, it may not have the opportunity to cool.
TLDR: It's possible, but there's potential flaws in the idea (in my opinion).
> How about limiting the current with a 1/2 ohm power resistor?
With automotive isolator installs the chassis is often the NEG return leg, which introduces significant resistance. My LiFePO4 banks typically charges at 0.2C in the middle of the voltage curve. Up to 0.35C at very low SoC and ~0.1C near the top. It's not an anomaly; I've been collecting data on it (favorable, unfavorable, all of it) and 0.32C seems to be the average max draw in most installs.
how much is the maximum current that the lithium battery can draw, would a 370 amp alternator be ok to use without a current limiting device.
excellent informative video as always.
Hi Edward,
Honestly depends on the battery itself and the management system inside of them. Because of the incredibly low internal resistance I honestly wouldn't be surprised at it still trying to request the full load.
Obviously this would be bad for a number of reasons.
1) Your cable probably isn't expecting to see 370A being dragged towards the batteries and, unless you have 95sqmm cable, or even preferably on the 120sqmm side, your cables and fuses are going to just disappear in a puff of black smoke.
2) In the instance that your cable is safe and stable to even transfer this current, the battery on the other side might really very much not like this. Lithium batteries should have battery management system (BMS) either within the battery box itself (as with ours) or on the outside with a dedicated BMS. Most BMS trip at a number of things as they care for the battery. You'll see three main routes of tripping. Temperature, voltage and current. If these things aren't monitored, IE you don't have a BMS or the BMS is just terrible, the batteries run a risk of being very unwell and potentially going into thermal runaway which is far more entertaining on a youtube video than in real life. If they are monitored, you have a battery that will suddenly be hit with 370A of current and will probably trip immediately.
When that 370A comes through (At an undetermined Voltage- Voltage of which can also just completely trip the battery) the BMS will trip, disconnect the cells from the terminals, and you now have a zero V paperweight refusing to do anything until it reconnects.
3) If, through some black magic, both of the above are actually fine- there's still a very substantial chance that your lithium battery IS asking your alternator for absolutely everything. It may survive for a while at the obscene temperatures it will be pushed to but, realistically, the lifespan of the alternator will be affected.
I think the above comments are fair and a decent explanation as to why you want to control this.
Cheers, and if you need any further consultation or assistance, I'm here to help-
B
lithium can be charged at 1c... that will mean if u have 500Ah lithiium battery will accept 500Ah but as thins great exemple shows us, it will destroid ur alternator... i am about to put together a project like this with 300Ah lithium battery to supply my small loads in the house, such as my aquairum light, filter, laptop, tv...etc... and i will put a video about it and how will work in time... because if its done properly and if its working well... u can supply a entire house.
@@radumihai7419 Hey Radu!
Mostly correct; one thing to mention though. Not all lithium batteries that you can purchase are 1C - as much as some people may want to suggest otherwise. Some cells are far better than others, and some BMS limit you far more than others. Always check a spec sheet before purchase so you know exactly what you're (supposed to be..) getting!
Cheers!
B
@@SterlingPowerLtd ok thank
@@radumihai7419 Hi Radu,
I don't feel as if my knowledge regarding the implementation and installation of lithium titanate supercapacitors within a lithium setup is as whole as it would have to be for me to recommend direction for you on this business account.
To my knowledge you can treat them as a standard lithium battery, however I do believe they naturally release charge over time. I never like to advise people to cross-chemistry, particularly if they have different rest voltages.
My advice, on the conservative side, would be to say to keep LTOs together and to keep them separate from LifePo4 and also to utilise BMS with them as they seem to have, at their core, the same dangers as LiFePo4 and similar sensitivities.
I'd advise you to consult your LTO manufacturers, and if you need further consultation, bring what they say to us so I can learn too :)
Ben
Great video! On my boat I have two separate alternators though. one smaller for the starter battery and 1 larger for the lithium domestic. I've purchased a dc to dc charger thinking I could put it between the larger alternator and the lithium battery but I don't think this is the case. What would you recommend in this situation?
Hello Joseph,
I'd advise you to direct both alternators to the starter and to install the BB between the starter and the lithium battery all the same. That is hopefully the easiest way to adapt your system.
-Ben
Why don't you think the DC-DC would work?
Who the hell buys a lithium battery and then then uses an internally regulated alternator. External regulator with heat sensors for battery and alternator.
People who don't know much about lithium, is the answer. Which, by and large, tends to be most of the public.
Even external regulators are often unsuitable unless they have current control, it's very worth mentioning.
Ben
Earth X has sold a lot to experimental aircraft owners with 60 amp internally regulated alternators ($500 overpriced ND alt from Plane Power). If they have a Hall Effect current sensor, they would see that their high priced alternator is maxed out during the re-charging of an 18 Ah LiFePO battery. Battery sellers are not mentioning this problem or the 32F low limit to aircraft builders.
@@USA-GreedyMenOfNoIntegrity We only advise people down particular routes from our own experience with charging lithium batteries and through particular charge sources. We would love to be able to recommend people to charge lithium batteries safely directly off of an alternator however we do not believe it is safe.
-Ben
Hi my 100A lithium has an internal resistance of 25milliohms which seems fairly standard from what I can tell at 50% charge, so achieving 90Amps at 13.6V across the battery terminals as shown in your app is simply physics. I*R=V so 90*0.025=2.25V. This means there is a voltage drop of 2.25V between the battery and alternator, in other words your alternator must be set to at least 15.85 Volts rather than the standard 14.4V. I was just wondering if you could explain how you managed to achieve the current draw. Did you increase the alternator voltage or reduce the internal resistance of the battery, for example by soldering a bus bar across the FETs on the BMS, or can you perhaps offer another explanation please?
Hi there,
Our alternator was set, if I recall correctly, 14.4/14.6. I cannot give a solid answer as we did not do any readings of the alternator voltage output at the time.
The current we saw was solely because of the lithium battery and their nature of running. Having an almost negligible internal resistance means that they will request all available power. From a mechanical source like an alternator, that means that it will be trying to draw as much current from it as it is comfortable to provide.
The alternator did not reach a high enough RPM to justify it's current output, and as such was not able to sustainably cool itself.
We recommend BB chargers in order to best control the current coming from an alternator and going to a battery, as do many of the western battery manufacturers.
-B
Thanks for your reply. The interesting thing about physics is that its easy to work out unknowns when you have knowns. If it was set as standard, the battery must have a resistance below (14.4V-13.6V)/90=0.0088. So 8.8 milliohms seems very low, personally I have only seen that resistance on a bank that had no BMS fitted as its the FETs in the BMS that adds the majority of the resistance. Perhaps your batteries don't use FETs and have a mechanical relay? I was looking at your batteries and cannot see a specification for the resistance (or impedance) at all. Do you know what it is ? Also whilst asking questions do you know what the final RPM was when it was overheating?
Doesnt the bms limit charging current?
Hi Rob,
In the same way that a draw-bridge limits cars crossing, yes.
If current is exceeded on a BMS, you get one of two realities
1) If the BMS has an over-current shutdown, the input MOS will simply disconnect and the charge current will go to zero
2) If the BMS doesn't have an over-current shutdown, we'll probably see BMS damage.
The BMS has no means of limiting current, merely of disconnecting if the current thresholds are exceeded.
Hope that helps a little!
Ben
Nice phone.
Thanks..! I think.
@@SterlingPowerLtd
You are welcome 👍👍👍
I replaced my old alternator as it no longer charges. the new one gets too hot to touch like the old one. Is it normal for an alternator between 100 and 130 degrees C? engine parts at a temperature between 70 90 C.
Depends on how the alternator is rated to run, honestly.
Some are designed to be sturdier and run at higher temperatures than others. Contacting your alternator manufacturer would be my first advised step- and if you need to limit the output from your alternator to keep it at a healthy level, we'll be happy to assist.
@@SterlingPowerLtd I have a valeo 105 amp 14v alternator. When the air conditioner is on, the vehicle consumes 50 60 amps. There is no problem with the cables, there is no voltage drop in the + cable. no grounding problem. battery ok. the only problem is the alternator overheating to 100 130 degrees. Where else could there be a problem? Thnk you for interest.
@@elsequitoelsen4779 I'm probably not the best person to ask regarding what's ongoing with your alternator. I'd advise talking to vehicle manufacturer or a local auto-electrician.
I don't predict that there's anything wrong with your vehicle setup itself. Cable probably is fine, or you'd be getting cables overheating or fuses blowing. If the alternator is overheating, the alternator either runs at too low an RPM or is just insufficient to cover the demands.
That'd be my considerations.
@@SterlingPowerLtd thanks again. Have a nice day.
@@elsequitoelsen4779 why do you consider 100/130° to be too hot? Certainly looking at his test and what he said about Brand name alternators it doesn't sound like you have any problem. Interested in your feedback. Lucy
Much cheaper ways to get current limiting isn't there? Clearly at 90Amps the voltage boost is not necessary.
Hi Liam,
Well, hard to say. There's not exactly many current limiting regulators out there at all and most of the current limiting chargers on the market do so utilising the same design idea as our BB product (which we originally got the Queens award for engineering innovation for in the first place).
When you're really sitting down and charging lithium there's a few things you want to be in control of and the BB really provides you with all you need.
You need to be able to comfortably control and ensure a safe voltage reliably to the lithium terminals because with any sort of notable spike, which can be expected if you're not utilising a controlled charger, the BMS within your battery system may just shut off entirely. Then, until it decides to reboot, you can't do very much with the battery at all.
Controlling the current is good, again, for both your alternator and your battery. A heavy current can trip your BMS again or, alternatively, just burn out your alternator.
You also need a charge system that will supply power continually in such a way that it can wake up your battery if it ever went down. Some systems refuse to make power available if it's seeing 0V on the other end.
We respect the BB isn't cheap but it is incredibly competitively priced for the quality of product you're receiving and it is a very effective carer and charger for your lithium setup, so long as it's installed and set up correctly. We're not just trying to sell this as snake-oil!
If you have any further inquiries or want clarification on anything, I'm here to help,
B
Hi again Liam,
Also seeing on my dashboard that you've commented on other videos but they no longer seem to be there for me to actually respond to.
If you want to contact us and inquire about your setup you can drop us a line through the contact form on the website and I'll get back to you ASAP.
B
@@SterlingPowerLtd Hi Charles. Yes I removed them, it could have been considered hitting below the belt.
MPPT Charge controllers offer similar current limiting and changeover compatibility with Solar.
As regards myself, I use raw cells so my custom BMS will behave as I program it to.
In all practicality I'm not fitting Li-ion. I can get the same performance from lead, lower cost means higher capacity.
Thanks for the feedback Charles.
On numerous occasions, I've fitted B2B units parallel to Albright Contactors and comparatively tested them. The difference is marginal (on non-regen vessels).
The B2B performs a little better with small batteries in the >85% SOC band.
Mostly I find the cable is doing the heavy lifting.
@@SterlingPowerLtd The comment that the B2B isn't cheap. Agreed. Why are you using CapXon electrolytics? What exactly am I paying for?
@@scruff7559 No longer is Charles who responds to people on the public front- results tended to be that people ended up getting offended lol.
MPPT solar controllers are brilliant because they do hold themselves back and they control the mental voltages that solar likes to produce. But you can't exactly use a solar controller to sort out your current coming from an alternator.
On the lead vs lithium front, lead definitely has their advantages and they tend to be on the cranking and price front. Lithium seems to be the route going forward when budget is unlimited and people have limited space or weight accommodation as you can just fit more usable capacity in the same space.
If your vehicle isn't Euro6 and your batteries aren't lithium, you can genuinely be better off with other units. Alternator to battery chargers come to mind as you can get the current through at a greater rate and you still get the boosted voltage.
If your vehicle is either Euro 6 or you need a charger that does current limit then BB is absolutely the route I'd recommend.
Regarding the BB price however- they're not exactly cheap to make. We're not making them for pennies and selling them at their price point just to screw over customers. I like to think that as far as transparency goes in our present market, we rate fairly highly.
They do their job and they do their job well. We're working on alternatives in both the cheaper and more premium market, but for now they're our offering to solve most power distribution complications.
I'm glad I saw this. I was going to completely separate my house LifePo4 bank from ever seeing the Altenator and only charge while the genset is on. Now I am comfortable letting the alternator do some work as long as I'm not trolling or idling for long. Boat motors run cooler than cars, and the engine bay is around 105. there are some other factors to watch for as when BMS senses issues, they completely cut off the power, and that would be like having no battery connected to the alternator also a bad thing for them.
Hi Jay,
So long as you either have a suitably rated battery to battery charger system, control over your alternators output current, or exceptional cooling to your alternator- you won't encounter any heating issues.
The turning off mid-charge is definitely a bit more of an issue for alternators, but there's solutions here as well. The APD (Alternator Protection Device) is one item designed to stop alternator spiking. Otherwise, a lead acid battery onboard and a battery to battery charger will do a lot to protect your whole system too.
Ben
Great informative video - thanks a lot for that. If you limited the charge current within the BMS to say - 50 Amps, would you still get the same effect?
Hello again,
No, I'm afraid not. The BMS has no means to actually current limit. Once the current is exceeded on the BMS, it simply turns off the charge MOS and renders charge current to zero.
Not ideal!
Ben
How about putting a temperature sensor on the alternator to have the external voltage regulator lower the output?
Hi Marc,
The temperature sensors largely settle on the external connectors to an alternator. The internal temperature can reach blistering and damaging levels long before it effectively reaches the studs being measured. You also probably wouldn't really want your alternator or charge system to continually cut off after 3 minutes or so and not getting an expected reliable charge.
Without a method of limiting the current being requested or transferred through in an almost bottleneck style, there's not really an effective way of protecting the alternator. The lithium battery will ask for everything available, so you just have to scale back what is available until it's safe.
Hope that helps;
Ben
@@SterlingPowerLtd What Balmar tells me (their extra-large case alternator and 614 reg, with alt and bat temp sensors) is when one gets hot the resistance on the F lead is increased slowing down the charge. I have a thousand amps of lead acid Trojan batteries and I have watched the charge go in the first hour of 20 hours till full. Would not lithium work the same way?
@@marccohen5579 Hi Marc,
As the temperature rises at temperature sensor points you will see voltage change, this is true; however it is unlikely that the temperature sensed point on the alternator stud will accurately relay the temperature found at the core of the alternator. The core will get a lot hotter far quicker. Also worth noting that a higher temperature often causes greater resistance, but that's mostly something to take into account with cable rather than alternators. Further, increasing the F lead resistance will slow down the charge rate but with a lithium battery that may very well just end up meaning that you're increasing the heat buildup down a cable. Ideally you want something that throttles the current rather than applies a gradual resistance.
Lithium works slightly different to other batteries for a number of reasons. Firstly, most batteries have a fairly substantial natural resistance. I could get a 400A alternator and hook it up to a 100Ah battery and most lead-acids would probably barely engage the alternator. If I stuck a 100Ah lithium on there (with a BMS suitable to handling a 400A spike..) I believe wholly that the lithium would try to absorb everything. Their internal resistance is the problem. They are happy to accept everything made available to them.
Another issue arises when we consider how an alternator actually cools itself; for reference it does so by operating hard. A higher RPM drives more air through the internals of the alternator and cools it down- an alternator on lithium, however, causes problems. It will be asking for 100% of the output of the alternator, however because it is so easy to charge it will only require about 60% of the RPM... We then have an alternator running at 100% output and 60% cooling, which even for short periods surely cannot be great for health.
We recommend a BB because it's the safest and most predictable way we have, at present, for controlling an alternator so it operates within known and safe variables, if that makes sense.
B
That's not a product Sterling sells so I would not expect them to speak approvingly about it on their channel.
Hi Matt. How’s things?
I think the Jackery is a very nice bit of kit. The 1000W version has a 1KW inverter which should handle most power tools as it has a 2KW surge ability.
The question is if your van installation is good and meets your needs, do we need this as well? There are so many variables aren’t there as we have different setups and requirements.
My van has 2 leisure Battery Banks that the Solar charges independently. This enables me to have different Types of battery and different battery ages. So the older batteries can go in Bank 2 that has less requirements. I have a modest Solar array on the van (210W) and not tiltable (is that a word?) so in the Dark Months I can struggle a bit. However a DC to DC charger and updated Alternator cures that problem! I also have a Honda E1000i that is a great bit of kit.
However, for me, having portable and additional power source could be a real bonus. I have a Narrowboat that I am refurbishing so I could just add Solar Panels & use a Jackery to provide more power. We also own a small holding. There is mains power in one building but others have nothing so this could be very useful, again with a Solar array in place to plug into. We often have power cuts there!
A WARNING however! The Jackery Battery is Lithium. A Lithium Battery will charge at high voltage and when connected to your Alternator in your vehicle will draw as much power as it can take! This can result in a destroyed Alternator so before using the Alternator to charge this up it maybe worth checking with Jackery. They could well have safety circuits installed but in normal circumstances you have to use a DC to DC charger that will regulate the charging rate and protect the Alternator. Stirling Poser explains this here: ua-cam.com/video/ShtGB07fCSs/v-deo.html Be carefull especially if you buy the 1000W version unless Jackery confirm it has a protection circuit installed.
For me however, I am pretty certain I am going to buy one, probably the 1000W and the Solar. The ability to tilt the Solar could well be a real bonus in winter!
Anyway, all the best.
HaHa, just seen the Stirling Power comments! So yes, good idea to contact Jackery!
Hi!
Is this from a consultation? If we can be of any further support in the future, feel free to reach out!
-Ben
Interesting, but you keep mixing up Amps and Degrees I think, making it a wee bit confusing, plus the noise man. Sterling might want to think about spending a little money on video production. This is very hard to watch.
Why does the specs on the Sterling alternator to battery chargers say it can charge LiFeON4 batteries but in this video you say you need to use a battery to battery charger? Also if I already have a 3-way isolator can I just install am b2b or a2b between my isolator and my home LiFeON4 battery bank but not my truck AGM starter battery?
Hi Raymond,
Pleasure to be in touch-!
Reasons behind this are both complex and simple. The AB went through a redesign when lithium batteries were coming out into the world. We made the LiFePo4 setting suitable for the Voltages that we found to be most suitable, but the integral flaw to an AB and a lithium battery is actually in the hardware of the AB.
The AB does not have any current limiting potential, and as such can not limit the drain that the lithium battery has on the alternator. We can provide the correct voltages, but we can't limit that facet with an AB. It should be worth mentioning that we have catamaran manufacturers in South Africa who run our ABs directly onto lithium batteries and don't seem to have any issues at all. It's been put forward that we might be being overly cautious, but I'd rather be cautious with our customers than put their alternators or batteries at risk.
As for running the BB off of the isolator; sure, technically very possible. We have a number of clients who put isolation switches on the input line to the BB, and this would essentially be no different. So long as it can take the alternator feed off of your starter battery in some manner, it's willing to operate :)
-Ben