Ebike Battery Combiners are they worth the risk?
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- Опубліковано 27 сер 2024
- We have had some issues of late with people using Ebike battery combiners. They essentially allow you to combine two batteries together to extend your range. Yet all you really do with them is save yourself the thirty seconds of time to manually swap a battery connection over. You can't charge them linked up. We do not support or condone their use with our High Voltage upgrade kits.
If you would like to learn more about batteries and building ebikes you are welcome to get join our discord community. highvoltagekit...
Our upgrade kit for the BBSHD which comes with full install and build support can be found here. As explained in the video we don't just send them out off a shelf. You need to get in touch first as each one is tailored to requirements to help ensure your safety. highvoltagekit...
**All images used in this video are covered under the fair use policy allowing for the reuse of content in order to deliver this information and message. **
I have been using several of these devices on my electric bike for more than a year, everything works perfectly. This is a very good way to save money by buying 2 inexpensive batteries and combining it in 1 more than buying a large battery of a large battery one 2 times more.
Glad it's working out. If the motor is only pulling low amps like 10-20. This is really aimed at stopping people using our kits that are running 4000+ watts and high amps for extended periods.
Could I buy one of your kits? Need a 80 or 100 amp combiner
Ive been using a 100 amp discharge converter for about a month now with no issues. I have two 52v 20ah batteries with 30amp bms on each battery. The batteries will supply my bbshd ludicrous controller with a peak of 2800w or about 52a combined from both batteries. The combiner and the batteries and motor run warm to the touch only after a high speed hill climb. Otherwise everything runs cool. If the batteries are fully charged at the same voltage the combiner will allow both batteries to deliver their rated bms current to the motor safely without cutoff. If one battery has a higher charge than the other it will draw this battery down at a higher rate until they are equal and then it will draw equally from both batteries. You can expect a 3-5 mph increase in speed and or a double increase in range.
The video was not really to worry people. If its a genuine 100amp with 100amp rated internal components you should be fine. If you have issues with one BMS it should just shut down in which case the other would trip. We don't want people running these on our kits because we just don't have the ability to vet them all and there are lots that are on sale saying 100 amps just because they have XT90s on them. The main problems we have seen are them just letting go internally or damaging the controller with voltage spikes. You may well be ok until its not. Its hard to say without knowing what you have. If its a ALI express one thats been market up from Area 13 or one of those places then I would not put much faith in the internals. Fingers crossed you are good for a long time :)
@@HighVoltageKitsI figure it's safe at half rated power or 50amps. I never run at 50a continuous except when hill climbing.
@@HighVoltageKitsI bout one and added to my Xclass 52v 18a battery and bought a second battery 52v 20a the blender was 40a and it messed up my bike No power from display any suggestions why this happened?
@@youngjay914tv9 did u buy a blender from amazon? i use a sparks cycle battery blender 30 amp with my og xclass 33 amp controller and 2 batteries 18ah and 20 ah. Been running it for 2 years plus now no issue. Just pedal assist at around 27km/h to 35km/h i can go about 100km pedal assisting b4 both batteries are dead. On our bikes it takes way longer to unplug 1 battery from the controller just to plug a spare in we have to undo a 4 screw plate then maneuver 2 of your smallest fingers only inside that small area where the controller is use 2 fingers to unplug and plug in a new battery toss all 4 screws back in the plate cover then your good to go 20 min later.... i asked myself "whats peace of mind worth to you"
I can keep way more capacity split between two locations on my bike than just one, both two wire BMS so support charging through discharge port, you can easily get a charge port on these devices if you purchase from the manufacturer.
And it's even smart charging, with the amps split between packs with different SOC so they end up finishing at the same time.
For me it's not about trying to get more amps out of one pack, it's about the longevity of discharging each pack at half the amps, without worrying about their voltage level when putting them in parallel. Less voltage sag, longer riding time, and longer battery life. I can also use just one pack to plug my 48v air compressor into and then put it back and know they will be back in balance soon after I start riding.
You could even use one just to get a pair into balance before paralleling them directly if you needed to for regen or whatever reasons, then the failure chance goes way down and you don't need as high of an amperage discharge rating.
Overall I find them to be very useful devices, though I can see ways they could be abused and if I started having failures I might end up being more cautious.
Good feedback and running batteries within their accepted limits is a good way to get more life from them. Much of this is aimed at people running our kits which can pull up to 4000 watts. The one place was suggesting you could draw 80 amps on them which is insane. Sure the XTs handle it but the components inside etc. They need to get good airflow. Sounds like you know your stuff tho.
Thank you for the advice. I have been looking at adding the battery combining device. My only thought was extending the range. You've made me change my mind. You are right, it only takes a min or less to swap out batteries.
You are welcome 😊
Everytime I unplug and replug the battery it sparks right between my fingers and scares me, even if I unplug it for few minutes, I am afraid the capacitor will eventually blow up one day when I am plugging it
I run two batteries in parallel always charged to the same voltage and then plug them in parallel and leave them together to balance out overnight...two years with the same set up and so far
So good,the bbq outhouse is still 🔥 standing....but I agree with the captain one battery and one bms is alot safer, from a safety point of view one 🔥 fire is better than two...😮
I think the shed would be toast regardless 🤔 Yeah it can be done safely until it's not. One of the biggest risks is having one bms trip. The one battery discharges and the other is full. Then if they reconnect the one battery tries to balance. Instant fire. I suspect that is what occurred with the very famous Rossman incident.
If both batteries have a common port BMS, then the batteries should be protected against such a scenario. I think a common port BMS with shared charge/discharge cable is the only safe way to do this. Obviously there was no way to confirm this after the fire, but Louis R suspects that they used a separate port BMS when he had specified common port. If the battery combiner is designed to prevent this scenario, and you have each battery with common port, then you should have 2 levels of protection. @@HighVoltageKits
That would explain more. It looked like a very rapid transfer of energy from one battery to another.
@@HighVoltageKits Daly BMS has a 15a charge rate and will trip. Common discharge/charge one is best.
I can only speak to my experience, but i have a 25 amp 36v combiner and have no issues. Ive paired my main 17.5 with three 8ah batteries i carry in my rear pack that i change out as needed.
Hey Paul. It sounds like you know what you are doing and are using it well within the specs. The video was not really meant to alarm people but to get people using our kits not to use them. They tend to pull amps above what the devices are rated for. Some of the devices are listed as 80+ amps because they soldered on XT90s instead of Andersons. Yet the internals are only rated for 40 amps. In the main it just means that the expensive controllers are being damaged. Appreciate the comment and feedback. I bet you get some crazy range with all of those! Cheers
@@HighVoltageKits your content is fantastic. I appreciate the topic because I was considering pairing two 100 amp 72v packs for space considerations.
Always wondered the issues with these. Thanks for sharing
Anytime Mick. Cheers
GREAT info for the New to Battrerys and the DIY world of what is Safe and Not . Love it Cap ,,,,,Keep them rolling in .
Greatings ,,DS
Cheers DS. I think there is so much drama on battery issues now. I want to look at real solutions from a calmer perspective and viewpoint. Hope you are well!
@@HighVoltageKits Doing good,,, 😁😋thanks for Arsking I'll DM y later on Discord. 👍
Sounds good.
I bought a Shengmilo M80 from new years ago that came with a second battery. I used a plain converter socket to allow them to connect in parallel instead of having to disconnect one before connecting the other. They are permanently connected together & charged as one battery. The result is a far more stable Voltage & power when ridden & lower amps coming from each so likely a longer lifespan. If I was to change the hub motor for something bigger then that would be a very different story, as stresses would increase. As it is, stresses have only decreased & I have every confidence that the bike & batteries will give me many more miles of reliable service.
Problems are more likely the result of overstressing components.
Hope it lasts for you! The only risk is a bms going bad in a way you don’t expect and it leading to overcharge or discharge of the battery. If they are good enough quality it ought to catch that though.
So you have two batteries connected together without using this discharge adapter?
@@johnravis3943 Yes, exactly that.
@@tvbridge hi my friend so is it easy to connect two batteries together? I want to extend the range of my ebike so my battery is 36v if I connect another battery does it need to be 36v? And can I use a bigger or smaller battery that's already on the bike?
Thanks
@@johnravis3943 Yes. The Voltage needs to be the same when connected in parallel. You can connect as many batteries of the same Voltage in parallel as size & weight allows. You really don't need any special connector.
The advantages are different than you say. I am running two 48 volt batteries (one 19.5ah and the other 24.5ah) with a battery balancer/combiner. Since the draw on each battery is much less when ridden hard, the battery heats less and is under less strain. I have nearly zero battery sag even on the steepest hills. This in turn promotes battery life. Also, the batteries will run longer than if each is ridden as a single back to back. I seem to be able to get about 20%= better mileage from using the batteries simultaneously rather than consecutively. In addition, since the batteries run down much more slowly, I get the full charge power from the batteries for a much longer time when riding after a full charge. In other words, the bike rides more powerfully for a longer period of time. So my take is, longer total distance, no battery sag, less battery wear, more voltage to the bike for a longer time. To be clear, I use a Samsung battery and a Panasonic battery, both good quality.
This was aimed at people using our upgrade kits which allow for higher power stuff. So we wanted to avoid them using two batteries to add up to one of high current which are pretty expensive to get something of quality. It was not trying to say never use these. If you know what you are doing then that's good. We were finding people using low quality ones and they were causing voltage spikes on controllers. Places are selling them with xt90s on them and saying they are good for 90 amps. If you have no sag under load then you are clearly operating well with the capabilities of the device. Thanks for comment. Happy trails Doc :)
i've been thinking about getting one, i hate voltage sag. which one did you end up getting?
Just balance voltage then plug them together. Amps don't matter in this case. Been testing this method for 4 years now. Just make sure voltage is +/-0.03v of each other. A common charge/discharge will make it safer as it can control any failures that would make it charge too fast. I'm writing about 1500w not 8kw.
Side note: I need to start putting warning on the start of my battery videos.
Yeah. Lots of the listings were suggesting higher amps than looked safe. We wanted to make sure people using the High power kits we do don't use them to combine cheaper batteries and use them beyond spec.
What warning are you going with?
@@HighVoltageKits Been using "My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is your obligation to ensure that you are complying with any local and federal laws as well as code and permit requirements." in the description but its a bit long for on videos.
Here google generic one "Be aware the use of batteries might cause damages of residual leaking, fire, or explosion when misused, mishandled, or defective."
100% agree, it's a solution to a problem that doesn't really exist. Bring an extra battery or even two and change when needed.
That is my take! Cheers
I'm sure if you hook up an IGBT, contactor, or maybe a thyristor, you could switch between the two batteries. That's the exact though process that leads to a blown up battery, motor and a fire.
Yes. They can work but its just not a risk worth taking IMO.
These are all good with low amp stuff like upto 30a if its rated for 50a, been using this for awhile, I guess if you want to run it with 4000w motor then you asking for trouble, and also the idea with this is to help eliminate the voltage sag when powering it .
Yeah. This is the main reason for this is to make it clear to people using our stuff its not recommended. The units say 40 amps on them yet one of the guys selling them is suggesting by sticking XT90s on there you can run 80 amps... Sure buddy. The connectors might take that but I doubt the electronics inside are up to snuff.
If you use them, be sure to turn off the recovery in the controller
Yeah they can't handle regen current that's for sure.
@@HighVoltageKits Because there is a diode that does not pass the current back to the battery
Ok so one way. Understood.
I use a dual battery balancer on my engine x, I have 13ah in the frame and a 10ah china blue on the rack. depends on the bike, mine folds so it's a bit of a faff having to keep unfolding it and wearing out the face plate contacts. these have been known to short out and melt. I bought a quality kit not these cheap aliexpress or ones off Amazon. mine came from the u.s and i paid a premium for it. everything about it was quality including the wiring and connectors. I've also installed a power analyzer too to see how much my large frame robs the batteries of power😂
Looks like you did it right! Cheers
Proper use case is you upgrade the motor with matching voltage, now you only need an extra $300 battery hooked in parallel to provide the needed current to the motor. Otherwise you’ll need to spend an extra $800 on a proper battery. Also in many cases, as in my case, I already have spare batteries which didn’t run in parallel in the past, but now can for the new motor, saving myself the need to spend any money on new batteries. There are dual-battery modules that safely combine two batteries, drawing from the higher voltage battery first a d going parallel once they match. This is safer than a straight parallel hookup where you must ensure voltages match before connecting them together.
Here, too, they use similar devices for a safe unification of 2 x acumulators, name video - " How to add a 2ND BATTERY to your electric bike (Safely) "
They are everywhere. They work until they don't
Very good video.
Am glad you posted this.
Connecting two together to get more amps sounds dumb and dangerous.
Connecting two together to get more range. I didn't realize we had to unplug them before charging. If that's the case, then yeah these combiners are junk.
Thanks. It makes it pretty redundant for me. Its like when people complain when the tap machine is broken and they have to enter a PIN number to pay for something. The issue with combining for amps is that often people use really cheap batteries to do this. If you combine so that the amps on each pack is to lower it so the battery lasts longer that is ok. But mostly people are doing it to extract more power and run them at their limits which is a great way to ruin a pack quick.
Wasnt it one of these, that caused Rossman 's bike to light up? Although it was a very crude, basterized one from what i remember
We will never know the truth there. In the UA-cam comments he said that the company accused him of using the packs with a 5000 watt motor. To which he replied that the BBSHD was a 1000 watt motor. Which is a huge reach. Even at 52 volts that motor hits 1700 watts peak. He was using 72 volt packs with an external controller which bumps up the power above 3000 watts. So the motor really is as powerful as the controller pushes. Alot of the people commenting have no idea what he was doing and just saw the fire. So it could have been a fault of the BMS or battery construction. I think he thought they would just cave. They maybe should have. Its done real damage to them as a company. If one of the batteries tripped while he was riding and then when he got back tried to equalize then it 100% would have caused a fire. There won't be a proper investigation and the evidence is incinerated.
Wow very cool 😎 i have a 72V Scooter with 5000 watt motors each, but only running 30ah battery 🔋, is it possible to use this to add a 20ah external battery in parallel Or avoid this technique altogether? Thank you!
I would be very careful as you are drawing a lot of current with that. There are some options that can go this high. They tend to be more expensive. We can't cover all of the options so we don't recommend them as it was causing issues with our upgrade kits.
Just get 2 good battery packs and connect it safely in parallel.
One of the biggest risks is having one bms trip. The one battery discharges and the other is full. Then if they reconnect the one battery tries to balance. Instant fire. I suspect that is what occurred with the very famous Rossman incident.
@@HighVoltageKits No instant fire. The other BMS simply switches off due to overcurrent
@@johgude5045 That depends on the pack architecture. Some batteries have no input protection on the discharge leads (so-called "3-wire BMS"). And that protection has to successfully work. Even in a "2-wire BMS", if the BMS is misprogrammed or the shunt fails in a way the pack cannot sense the input current, the pack will overcharge and overheat.
@@wool1701 to be more precise: the battery that loads the sink battery should cut off due to overcurrent event. No instant fire. It's generally not smart to use batteries without overcharge protection, or "3wire BMS" if there is a chance to charge them through the discharge port. I dont have any 3-wire BMS in service anymore since almost 5 years now
@@wool1701 If your BMS does not shut off during overcharge or overtemperature event, it is time to look for a different BMS. You cannot blame this battery combiner for this
It would be easier to just get a 2 pole 3 way switches to switch battery wouldn't it?
Possibly although getting something suitable for the Amps that is the right size and easy to mount might be tricky. But not attempted it myself.
Yes , i can tell you first hand what happens, about 3miles in you will get a POP and a puff of smoke, then peddle your ass home , it happen to me last week. 2 52 volt batterys,and a 100 dollar battery blender on the high voltage 855. So yes. WARNING!!! THANKS HIGH VOLTAGE FOR GETTING ME GOING ONCE AGAIN.
We always look after people. Appreciate the comment. Glad you will be up and running.
Be interesting to see how Bosch does it with their dual battery configurations. Like on the Tern GSD. I believe they both charge at the same time. Never have to worry about it. I ride like a "normal" person and not a hooligan. I believe "The Great White North" is a "class 1&2" country only. I also googled "Idaho stops" and TGWN is also a no no land. I do a "Spokane" stop. Close to Idaho, but.... ;) Hows it going John?
Going good mate. Summer is winding down but we get a nice long end of season here with cooler nights. We still really need rain but the smoke is now gone for the most part. The video was more aimed at advice for people using our kits. If Bosch are using it then it will have to have been checked. Most of the stuff I referenced is being pushed by people buying ultra cheap on Ali etc and then selling on for a hefty markup. Then using cheap batteries in combination to save money and pulling their amp limit through a device with maybe $5 of dubious quality components. In most cases when they go its not a battery fire but they do routinely toast controller when they let go especially the cheaper ones. Hope you are doing well. What is a Spokane stop btw?
@@HighVoltageKits A "Spokane Stop" is a bit like an Idaho Stop (that you do), but the rider slows down to look.;)
I think those combi boxes are burnt from people trying to suck too much juice out of the combined batteries. Surprised that the battery leads didn't melt from the excess current draw.
You had any problems with spoke nipples pulling out of the rims from going "full Hooligan"?
Which three-position switch will be good if the maximum current is 80A 72V?
Hi. I can’t really advise here. It’s not something I have tried. You need to make sure it can handle high current though. 60-80 amps likely.
How about do some testing these at the high wattage and prove what you are saying? I have been using one with a bac2000 and it has no issues at high watts.
I have seen this mess up 855s never mind a 2000. I have zero interest in testing these with any of my controllers. We don't support them with our kits. Not sure which one you are using and if you are happy that's great. But I will be sticking to switching batteries. Most of them even say not for over 2000 watts in the website listings.
@@HighVoltageKits I'm using a 90a rated version from electromotive mods and have rode 2000mi with it so far and no issues. Have pulled over 2000w+ no problem on multiple occasions.
I think what you have might be a cut above the dross that's being marked up from Ali Express.
@@HighVoltageKits seems you missed that clarification on the video and grouped them all together?
I hear they are a good way to blow up the controller if it's a smart type of controller
Even the 855 can be wrecked with these mate.
@@HighVoltageKits lol, a controller that blows since the battery does not accept charge is a waste of time anyways. What if the battery is at high voltage cut off level?
Most controllers have some wiggle room to allow for voltage spikes.
Not worth the risk. Just connect a trip switch to each battery or fuses. Works for me. Then you can switch them in and out and the breaker rcd switch will go if any shorts or anything occurs. I have two bms attached to each battery, which can be switched between the two.
What about a battery switch, much safer and it saves you the plug and unplgug routine, what ate your thoughts?
Could work if it's done right. There are expensive combiners that can work. We just don't want people using cheap ones of dubious quality with our kits. Do your learning and you will be ok. You are welcome to post stuff on our Discord as well.
I am going to ask you a question, how do i make my restricted 15.5mph bike slightly faster as in how do i un-restrict it, its a gtech sport and has controller and bms in bottle battery mount, just asking lol as you sure know your stuff.
Best bet is to post on our Discord community. The link is in the description. We mostly deal with DIY stuff. I know there are devices that derestrict and people may no. I don't have personal experience doing this so I can't say which devices do or do not work. I believe most can be hacked tho.
I have a A-Ride Alpine scooter, the battery is built in, just wondering what my options would be? Would like to increase my range.
Probably find a way to hook up a second battery that you take with you. You are welcome to join our discord and post photos etc. Be easier for people to help you on there. The links in the description.
Ok. I did join Discord, not sure where to start on there. I ll give it a try. Thanks.
@rayhwilson cool. Post in ask a question
if you are so inclinded, you could install a triple position switch. with an "OFF" in the middle and "Battery A" left "Battery B" right
(or something similar) but it is pretty easy to just switch plugs lol
Like a dead man's switch with a generator and grid power. Yeah it would work.
@@HighVoltageKits there's no way you could accidently run both packs at the same time like this. Just make sure it's well insulted 😅
What is wrong with the audio quality?
Hi thanks for video i would like to ask what happen when i accidentally connect two ebike batteries togheter? One is fully charged 54,6v other had 44v. I did it and from my perspective nothing happend but i want to know what could happend. Please help
Hopefully the bms would protect it. But if not then the voltages would try to equalize generating massive heat and potentially explosive fire resulting.
If you connected a discharged 44V 10A battery to a fully Charged 54V 20A battery the latter would want to dump something like 10A into the discharged one.....not a problem for the charged one but it would be like connecting a 10A charger to the discharged one. Potentially an issue for it's cells if it's BMS doesn't control charge rate. Change the sizes of each battery in the scenario & the rate Amps of charge/discharge also change, obviously, but never above 1C in either battery, so I can't see any problem. I've equalized batteries more times than I can remember with no problems.
Just taking a moment to be childishly pathetic, but I was the 69th like.
"Rule #32 - Enjoy the little things."
Yes 👌🏼
My only problem with these is that they are way overpriced for what they are (Schottky or bridge rectifier..etc).
They are listed for $20-30 on Ali. The US retailers are repackaging and marking up to closer to $60
@@HighVoltageKits yes, and what make the circuit is actually about 5 bucks including the xt60s at best.
Exactly why they scare me
Bridge rectifiers are terrifically dangerous for this purpose as most are rated for AC current, not DC. So they don't expect continuous current on only one path.
A possible failure scenario for a bridge rectifier is a short, allowing current in both directions. Which would allow one pack to charge another.
@@wool1701 not true.
A diode is the only part needed, and some components work better than others.
You need different voltages for batteries to charge each other, if you connected a 39v to a 48v in parallel with or without the device, you're asking for a disaster .
what means your kits whats means your kits? "your kits" are just picked from chinese web, tested and rebranded by you, yes, but are not your kits
Er no. We use ASI controllers which are tuned and configured by us and paired with display etc. Some components are manufactured in China like almost everything these days. But the harnesses, assembly, testing as well as manufacturing of 3D printed components is USA and Canada. So no it’s not just some rebranded Chinese kit :)
Battery combiners are junk. you probably won't even see a teardown of one on my channel!
Not much to take apart really! Be a thirty second short.
@@HighVoltageKits Something about like that RC high side mosfet switch I took apart.
tear. it. down. !!!! tear. it. down. !!!! DEW IT!!!!!
Tear one down , no point calling them junk if you haven't own one or tear one down yet, it's like someone saying bafang motors are junk but never owned one or ridden one
@@robw5735 It's a battery combiner. What exactly do you think is inside the little box that is so special?
Iv seen these going for £250 on a Facebook page working with 5 batterys and charger port for max of 90amp discharge 😅 yeah no thanks
There are some that are meant to be ok. Its just there are lots being sold be people that are marking up cheap stuff. There is no way to validate them so for our stuff we just say we can't support them. I just don't see the benefit for most cases. Cheers
@@HighVoltageKits I honestly stand by everything said in the video, either get a second battery and swap them over or get a bigger battery. Lithium fires are no joke and potentially damaging the rest of the bike and components isn't worth the risk
Yeah. Most of these it's less lithium fire and more damage to controllers. Unless they try and charge them connected.... Yeah I'm not using them.