As an Electronics Technician, with many years of field experience (yeah, old schooled in TVs, who also keeps up to date on tech) I can vouch for this excellent presentation. I began watching the video and had to smile when you came to the point that BMSs do not provide any feedback of the state of the individual cells, therefore makes no sense to use them, specially when one cell goes whacky and the BMS shuts down everything. Thanks for putting it together and to the people who gave negatives to the video, you guys don't know squat about LiIon batteries and basic electronics.
Thanks, I'm chuckling. It's an old saying to "not know squat" I believe it came from the era of the paddlewheel boat captains making their way up and down the Mississippi. If you didn't know "squat", there was a good chance you would run your boat aground on a sandbar.... Is there a metaphor here?......
I rarely comment on videos but I had to this round. This was an outstanding and informative video with a very good option to an aggravating issue. I see this solution 10 fold better than pretty much all standard styles and 95% of any non-standard ideas for doing this. Love it and for sure recommend.
I also make a video on bms inspired by him visit my channel to watch the video. in my video you got everything about BMS Topic cover in my video is:- 1) how bms work 2)how to choose the right BMS 3)how to connect a bms 4) how it's work 5) if BMS take care of series what about the cells that are connected in parallel
I can't say for certain, but I seem to remember some BMS units that have Bluetooth and/or WiFi commo that can do what the "loggers" do, and send the real-time data to your smartphone as you ride. They also had an alarm feature in their "app" that provided both audible and visual cues from the phone to the rider. ...and here I am talking about using an "app" when I have always warned about relying on any tech that REQUIRES an "app" to work for you...the fact there is no guaranty the "app" will be around next week and could be unilaterally removed from your phone at any moment without warning (company goes out of business, stops supporting it, to continue working it requires you replace your phone with one that has a newer version of Android/iOS, etc).
Hey Shawn. Excellent video! Your approach sits really well with this retired instrument engineer with a serious DIY inclination. I can't wait to build my first battery pack and put your approach into action.
Thanks for letting us in on this. I just went out and tried to see if my ego hedger would work with just 56v without its bms and it did. This will save me lots of money. Thank you Rocket Man
Agreed, it validates my work based on what BatteryUniversity says about prolonging lithium ion batteries via undercharging and that BMSs are an unnecessary additional point of failure.
I have an iCharger 208B for going on 10 years for my Yuba Boda Boda. I like it and use it for other projects as well. I run LiFePo4 batteries in (2) 24 volt packs. and charge them with a 4 pole double throw switch that charges the packs in parallel and runs the bike with the packs in series. I charge at 3.5 volts per cell and after 5 years on this bike with this pack, 5 back tires, 2 chains and gear clusters. and 1 back wheel they are only .3 Amp hours below rated capacity. The darn things will never wear out so I have no excuse spending a lot of money on a pack upgrade. No BMS.
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Really glad I found this video before I build my pack. I've gone BMSless and have no regrets so far (300 miles of riding so far, and ZERO Balancing needed using 280 used laptop 18650s). I'm waiting for a little 8s voltage display that cycles through the voltages of each series, it cost me a $1, that's the kind of feedback I want.
Glad I stumbled upon this. As a “newbie” to this stuff, I couldn’t understand why BMS’ are held in such high regard when 90% of the reclaimed cells I have so far are good cells and bad BMS’ (it seems). My logical brain said “wait! what about safety!” But when I heard the little alarm go off? A little alarm went off in my head. I want to be in control, not a nameless, faceless (silent) BMS. Visions of exploding LiOns ...umm..exploded lol. Bravo! As I tell my customers, “ I like my smart devices to be smart when I want them to be...and very dumb when I want them to be. “ Your approach seems logical. Great stuff and pretty funny too lol.
Good video. I've found that battery packs last better when cells are in parallel as the cells keep each other balanced. I use 3x 4S4P in series for a 12S 20Ah pack without a BMS. I can split them at anytime for hobby charging but prefer to bulk charge using a constant current 10A LED driver with Max voltage set so that cells do not exceed ~4.1v. I occasionally balance each 4S4P pack separately using hobby balancer. The 4P setup keeps them very well balanced.
If this is indeed more efficient / better balance and longevity why don't battery pack companies and DIY's build their batteries in this manner as you described?
@@connicrow9463 @Conni Crow they do, except they always add a BMS due to the nature of lithium batteries. I was confident on my pack because the sense wires (also paralleled) were very small therefore naturally limited current (like fuse wire). I did end up losing multiple paralleled cells when one went bad, but this is normal in any pack. BTW, as proof, my current bought battery is 13S(7P) compared to the long gone homemade 22S(4P) - I now have BMS security(cell charge limits; cell balancing which really is required as every cells different)
Great video Shawn, I made an ebike last year using 10 x 6S 5Ah lipos to make a 48V 12S 26Ah pack and don't use a BMS. I charge using a Turnigy Reaktor 300W 6S charger in two sessions, and as often as possible from 300 W of home made portable solar panels, that weigh about 6 lbs, fit in a backpack and can be laid out anywhere. The pack is capable of giving 12kW of power, though I "only" use about 1.5kW, and that is plenty! I just made a couple of extra cells using 16 18650s per cell (~36Ah each) so it can cope with 30A and 50A burst regen, and now gives me 14S, though regen doesn't work until the voltage drops 1/2 an S, as I found out when I needed to brake the first time I tested it! Yes, I know the chemistries are different, but I charge them individually and make sure voltages are always within spec. (Just a note about XT60s / XT90s - lipos use the female type, so I'd recommend following that convention for compatibility). (I put a video up showing my pack, charger and solar panels on my channel if you're interested)
Hey Shawn, great to see someone accurately describe those Battery Murdering Systems! One thing I would suggest though...you can reduce the effort involved in bulk + balance charging like this by just using a balance tap only charger like the BC168. Yes the balance leads/plugs are somewhat limited in current carrying capacity, but if you limit the charge rate to something reasonable it can and does work. I've been doing it like this for over 4 years now. Cheers
I watched your video 10 times and I rephrased my question again. 1. I'm planning to build my first battery pack and convert to ebike, and you convinced me to spend more on good smart charger. I looked up iCharger 1010B+ but max output V 40 with 7 A, so by charging not to 42V but 40 V , I will extend my battery life. Please confirm that 1010B+ charger will be good for 36V 15 amp pack. What power supply would you recommend for this charger? I found Junsi 350 - Outputting 350W at 23A/15V. Will it be good? 2. If I get 10S charger but cell logger can only take up to 8s, can I connect 2 loggers 5 s+ 5s (not physically splitting the battery?????) and have extra port with JST-XH 10s for my 10s charger so I can charger my my 10s5p battery as one? 3. Mr. Jehugarcia, talks about bottom levering batteries, should I then go up on the charger and get PowerLab 8 to do both smart charging and bottom levering of the batteries?? Thank you a lot!
Thanks Shawn for this great video! I'm now convinced to use a hobby charger to charge my ebike and no longer rely on a BMS. The only small "issue" I see is with the cell logger: this thing will be powered from a single cell and so it could slightly drain that cell compared to the others, thus generating imbalance... Is that a problem in practice? Or are there any cheap cell loggers that are powered from each cell one at a time? Thanks!
I have been using this method since 2017 on all my battery packs on all my ebikes. Thanks Shawn. I've seen some comments about a newer type of BMS that replaces the need for this method of charging. If you are one of those persons please point me to a BMS that can limit a charge to 80% and balance at 80% as well. Ive seen bluetooth BMSs and have had one in the past but couldn't see how i could limit the charge to 80% and have it balance all at the same time. Thanks for any replies or links.
Hey Shawn, this is the BEST anti-BMS video I have watched so far!!! I don't use BMS myself for the same reason as you, there's no feedback and I don't know what that little cheap and nasty PCB is doing. Most batteries (to not say all batteries) I repair have a problem related to a faulty BMS. The cheap ones don't balance the cells at all they actually KILL cells.. last thing you want is "a device that will unbalance and kill your battery". BMS also makes things unnecessarily a LOT more complex, that doesn't encourage people to make their own batteries! I made a pack with Panasonic PF back in 2014 and last time I balanced was almost a year ago, I run it hard 1500w every single day, guess what, almost one year later the pack still balanced. On the other hand I have many videos showing "how to install BMS" because from a bike shop perspective, most ebike users have absolutely no clue about electronics so in this case the BMS is more reliable than some humans. Congrats for this video, I will recommend to many people here when replying comments in my channel =]
Hey Thanks Bruno! I'm pleased that you have come to the same conclusions that I have. Tell me, how far would you let your pack get out of balance? .1 volt, .2 volts? And what cell voltage do you charge to to be safe- 4 volts?
Hey Shawn, good questions haha.. at work I have to be a bit more strict with balancing as the pack wont be under any monitoring apart from the BMS, most BMS will cut above 0.5v so I try to keep it below 0.2v after multiple cycles to ensure this difference is not growing and the pack is stable. I do charge my 14s all the way up to 58.8v which is 4.2v per cell, it takes a LOT longer to charge but in my case I performance is more important than range and the pack life. For a regular commuter I would say 4v per cell is all they need, really liked you mentioned many times in your video that charging to 4v you can double or triple the cell life, most people don't even know these things. POWER to the people haha =]
i've been thinking about this for most of the day today. it must be possible without the BMS. ZACK! now I have seen you....many thanks and greetings from germany
Agree 100%. Your battery is only as good as its lowest capacity block. Once it is full, charging should stop. There is no point in putting more charge into any other block, its just a waste. My Idea is to monitor and display each block voltage and auto disconnect the charger when any block reaches 4.2 volts. Less if you only want to charge to 80%, to lengthen battery life as with Tesla. Likewise turn of the load when any block is down to around 3 volts. To really balance a pack it is best to make sure each pack has the same Ah capacity.
Thank you, this is exactly what I was looking for. I suspected that the tiny resistors on a BMS were not capable of applying enough drain to actually balance the batteries. There's a reason the hobby chargers need fans to stay cool, and that's because they're dissipating off more energy as heat to actually balance the packs. I also really appreciate you showing how you wire the batteries to split them for charging as 2x 7S instead of one 14S. Hopefully now with EVs becoming more common, larger and better chargers will become available for charging 12S - 16S packs used in EV setups.
just a quick update. I have assembled the pack using your method of no bms. still waiting on the new volt checkers as the first type are a waste of time. balance charged the pack to 4.1 volt traveled approx 50 km and stop to check voltage on cells from time to time. they haven't drifted at all. bulk charging now and will monitor every 30 min. thank you so much. you have been a great help.
That's great Antonio! I love it when someone actually builds one of these packs. You can use the over voltage alarm on the cell checkers so you don't have to physically watch the packs....
I hate to be the one to say this, but this isn't really practical. You can easily buy a Smart BMS with Bluetooth which can monitor the cells which makes all this clever engineering obsolete. I'm not saying this won't work, but it is a freaking hassle and if you don't hear those voltage sensors beep, (I have several of those) your really in for it. You don't even mention a battery monitor to which you can look at from the handlebars, I'd have to get off my bike every 30 mins to check where my battery is.
Thank you for taking the time to put together such a non BS video. anytime I am told I have to use something I ask why and if I don't get a satisfactory answer I usually find it is a lawyer insurance company or Corporation.
Please excuse my ignorance, I don't understand how the charger or logger can see individual "cells" when everything is connected together in series. Does it do the math for you and work it's way out along the chain? Could you do the same with a multi meter manually? Sorry for the dumb question, this is all new to me. Is that batter pack both parallel and series combined? 14 long in series, and 5 wide in parallel? How does the charger target specific batteries? Does it bring everything down to the low water mark, and then charge from there hoping that everything will be even afterwards?
Great questions! The logger or charger starts with the negative terminal of the battery. Consider that "0". Then it goes to the positive of the first cell. Consider that 4. Then it goes to the positive of the next cell, consider that 8. Then it does the math and deduces that the voltage of the 2nd cell is not really 8, it is 8-4=4. Etc. The charger charges the entire pack in series. Using the same technique, it monitors the voltages of all the cells. If one exceeds the set limit, say 4.2 volts, it turns on a resistor through the balance lead connected to that cell, and attempts to reign it in. Failing that, it reduces the charge current. Failing that, it shuts off the charge.
@@shawname2 enjoyed your vdo & info, correct me if i'm wrong but in your explanation above, each voltage point being measured w/data logger is that of 5 "cells" that are in parallel, not an individual battery "cell", thus it's possible that over time you would not know if a cell or 2, etc. has opened ( out of the 5 ) and/or developed a failure mode resulting in high internal resistance ( won't take a charge/shows few millivolts).. ( by wouldn't know i mean other than your range would be lower...pack produces less amps, etc. )
Good comment. Yes, it does the math and works its way out along the chain. You could do the same with a multimeter or a voltmeter hooked to each parallel group. Yes, all batteries are made up of cells connected in parallel to multiply amps, then those parallel groups connected in series to multiply voltage.
@@robozstarrr8930 yes, i thought that too, it's a disadvantage of the parallel/series system as opposed to the series/parallel. In the latter it's much easier to determine your bad cell, but seemingly the advantages of parallel/serial outweigh this disadvantage
please, tell me more about 17:30 calculation! supposing one 7s pack, if I use a constant voltage power supply of 28V instead of 30VDC or more, the BMS cannot charge at 4.2V per cell, stop charging each at 4.0V and the number of cycles increase a lot ? of course the mileage full at 4.0V for each charge is a little less than the pack with 4.2V but a lot more cycles are really good.
4.0v saturated cells are 80% charged. If that is not enough range then better to add more cells than to charge to 4.2v which stresses the cells and saturation cutoff is critical.
I agree, and when there is room. But it is good to have the option of still being able to charge to 4.2 in case you need the extra capacity for a long long ride. It is good for a knowledgeable human to make that choice, not a chip!
I confirmed your conclusions the hard way. After failed bms after another, was heading back to the Imax. I will be splitting my 10s packs into 2-5s. Thanks!
Watching this in 2019. Now you can get BMS with bluetooth and monitor cells(ebay and aliexpress from china) I'm going to assume that the BMS intended for 300 amp charge/discharge is going to have enough balancing capacity to handle an ebike no problem. There is stil the issue of the BMS cutting power mid-ride if it finds low voltage. Price is around 120 USD from china. I am waiting for mine to arrive. I hope it works well. They come with a flat aluminum plate as head sink on both sides of circuit because there are mosfets to pass current on both sides of the board. I will be mounting finned aluminum heatsinks using thermal conducting tape to both sides to keep the board cool. Solves a lot of complication, hopefully it works well and reliably. Thanks for reading.
Let's see how that works out. Times change! I'd love to have a really simple balancing solution for ebikes. Now I use active balancing on the power walls, that is working out well.
I agree completely with you, before I found this video I have been struggling with small BMS to use on small battery packs, so far all that has happened is that I have managed to ruin far too many batteries. I know it is a long time since you did this video, but I would love if you could direct me to the cell logger you show or something like it. I like that it just does one job. Many thanks in advance.
Ok, so just to be sure: you can ''bulk charge both at the same time'' meaning you use the balance charger in another setting in order to charge? And then, when you want to balance charge, you separate the 2 packs and then charge them one at a time (assuming you have only 1 charger)? Thumbs up perhaps so people can see.
YEs, that is it. But you can bulk charge to extend the life of the battery by keeping them connected together and charging both at once. Either with the balance charger- not in balance mode- or a separate charger.
Awesome stuff bro...my battery tipped over and hit the concrete, I couldn't fault any cells so bypassed the bms...better power now and I just keep an eye on the cells after every 5 rides
Does this still apply to today’s cells? I have two 52v 20ah in parallel with a 80a controller 3000w hub. Will it blow? So, should I bypass bms? You explained this bms thing perfectly, thanks
"tripple the life of a pack with a bms" this assumes all bms use the same balancing methods... they dont. "a better battery pack with out a bms" False. If you take the time to select the right components for your build ..and go down the path of an active balancing/charge redistributing bms... it will be better in any objective measurement of "betterness" you wish for two packs to be compared.
The guy made his case with some products and useful info. Can you share some products and examples? GENUINE question because I have a 52v 20amp battery that I recently experienced issues with ... guess what it was? OOOOOOH ya, the stupid junk BMS. the battery was reading ~28v and when I checked it before the BMS it read a fully charged 58.6v
@@atefamriche9531 linear Technologies. You probably need to make a circuit board but you can do things like active balancing during run time or in other words cell groups prop up a weak cell on the fly
Thank you for making this video, there is a lot of conflicting information out here. I have a first generation fiido T-1 and it's replacement less battery. I put battery in replacement and immediately noticed battery discharged faster so I ordered a 48v advanced 300w Luna charger w/ 80 90 100 % settings charging to 54.6v @ 100% now 13 mo. old full is + or - 52v it varies each time. Now I understand why, unbalanced. Bike was shipped to me without user manual or the download. Took 4 months to learn full charging shortens battery life. Guido recommends full charge after EVERY ride.
It is good to let the battery sit on the charger and charge fully and slowly, every few months as it gives the BMS a chance to balance the battery. It will only begin balancing when a cell hits 4.2 volts... But not every time, or the battery will not last as long...... Sounds like you have it figured out!
Hello, Shawn. I I have a iCharger x8. Want to set up its charging capabilities. The pins start with negative on the left. ( 10 pins ) . In your video you don't say exactly how many positive wires connect. On this 52v 21ah battery of mine, all the wires are hooked negative. I observed your positive wires and the next 3 positives. But I can't determine the exact cadence of positives and negatives of your battery when I have 12 batteries to a cell. And your spot soldering starts between the actual top of the batteries. I don't have a cell logger . Hooking up right to the charger. Oh , empire of squat-ness, I need advice
Very informative. I have built a 7s8p and 7s10p li-ion packs for my scooter with brushed DC motor. Because I need a 12v source for the turn lights, alarm and other electronics. How will I make the center tap and split? 3 and half S each or 4s and 3s or 4s each? If 4s'es each there's no 24v standard charger for it. Thank you.
One of the cells was 4.2v maybe the weak one like you said as charges faster some just 3.9 this a big discrepancy so my cells in parallel rows of 5 if I use a 12 volt light on that row or maybe a group of 3 ?=12v will that be ok to balance charge?
"Stay within a 100drths of a volt whether you have a BMS or not"..COMPLETELY untru. As a matter of fact the higher amperage you draw the more they will vary in voltage as they are discharged. "If your battery is perfect you dont need a BMS"..lol..what?..I make battery packs and use Panasonic NCR18650PF cells and I can tell you that after drawing 50 amps of discharge (burst) and an average of 25 amps continuous, they ABSOLUTELY do vary in their voltage and without a BMS the weaker ones in Parallel would hit 4.2 volts first and then get overcharged. Here's a hint; not all cells even quality ones are created equal!!. Of course the problem with using a hobby charger for balancing is that on the discharge side, the weaker cells will hit 3 volts first while others are at 3.3 or higher, and if you think that doesnt happen, then you have NO real experience working with these cells, and in my opinion this video is very dangerous.
OK! Did I say a hundredths? Let me correct myself then. I balance when my batteries are 2/10ths of a volt out. "If your battery pack is perfect you don't need a BMS" is a thought experiment, perhaps I am wrong to assume everyone knows that everyone knows that no battery is "perfect"- or to be more precise, stays perfectly in balance. Using the hobby charger for balancing and monitoring the cell voltages with cell loggers to know when your cell hits a pre-programmed low like I advocate is tried and true in the hobby industry. They run very high C packs without BMS's using this technique. The battery packs on my ebike are still working very well after over 20,000 miles and four years using this technique. It takes me overnight to come within three hundredths of a volt balance using my hobby charger, an icharger B-10, and I know this exactly, there is no guessing . I bulk charge to four volts normally and balance charge about once a month. Thank you for your passion! I think we both care a lot about batteries!
Thanks for the reply...I didnt mean to come off sounding so snubbish...and yes we both have a passion for this..I make and sell battery packs and almost all unfortunately, have to be installed with a BMS. I have gone through many and there are good ones and there are bad ones..I am currently using Supower BMS units and they have so far been ok. Bestech have been terrible for reliability. I personally have used battery medics for my headway 24 s pack, but that's me and not many could do it...I sold the remainder of my headways to a customer and he wanted to do his own balancing but couldnt do it even after I balanced the cells to begin with. Im not saying it cant be done but most cannot ;)
Not a problem at all. I also checked out your kits for building battery packs using magnets. I would wonder how much resistance one would expect connecting cells in this manner..of course when building a pack you want to eliminate as much resistance as you can to have the best performing pack you can make.
I agree. I overcome with mass- by building a very large conductor- the higher resistance of 1010 steel. The steel is also zinc plated- which conducts about as well as nickel. Also the distances are very short. This was of course very much in my thoughts when designing BatteryBlocs. All I can say is in practical use the steel does not seem to be an issue. If you have a way of measuring resistance very precisely I will send you some sample Blocs and you can report back.
Hi just been down on electric bike 48v1000watt one was goin ok up hill then power went down some faint lights on throttle display .peddled home checked battery still 54.8 v it’s a48v motor and controller is that ok ?must be controller I hope will check motor after 😀
As someone with a electronics and communications degree Please do not and i repeat DO NOT make one of these on anything bigger then a 4 blade drone. The issues and DANGERS are very real on any none BMS pack after a certain size.
Thanks. I always go with "respect your LiPos". The fire test videos are pretty inspiring. I think the author's approach works fine for small packs but it starts to get harder to manage over a number of cells.
Samir Yeah i agree but the cell he is working is way to big and could easily short out, my quadcopter has 26 amps in storage to use and if i did what this guy is doing it would burn my house down or kill me in the process.
I shorted a 5 * 12V Lead Acid pack (40 Ah) once and the flash blinded me for a few seconds, took a piece off my plier. To this day I thank god it wasn't LiPo. And I think that every LiPo pack, BMS or not should have a fuse in series to make sure that stuff like that doesn't happen. I was working on the stock charging circuit that was unprotected from factory.
Yeah i work with 2x110 volt battery banks about 2 times a week on faults and issues these things can pull 100 amps in a split sec if you are in the way you are either dead or in hospital. What he is doing is ok in small units but can in bigger units like the one he is playing with can cause a cell failure and if it goes into meltdown as i call it it's a chain reaction nothing can stop it. Perfect example if this fool gets hit by a car and is stuck under the front of the car and the batteries short out and the bike is on him it's over he will be burned very badly or killed. THIS IS WHY tesla have 6 amp micro fuse on each battery. .
Having a micro fuse on each cell is a great idea. But no ebike or hobby packs have that technology. Yes the bigger the packs are the more power they have the more potential energy they have- to power your device or if they get crushed--- to have a thermal runaway. Same is true of gas tanks. If you are going to make batteries or internal combustion engines or hydrogen fuel cells know the risks.
I would put money down this guy is right, you don't NEED a BMS, but I am cringing thinking about the number of wires on any of his bikes. A quality BMS could be used with one of the battery log devices to keep the feedback loop. Absolutely deserves a thumbs up for the video and for leaving an email address! Nice work, great video!
This is a good comment. Yes, a quality BMS with good parallel group monitoring is a good solution. A toggle switch is wired into the negative of the cell monitor. A two to one splitter on the JST wire harness reduces the number of wires. A BMS bypass switch could be used if the BMS shuts off the battery but you still want to go a little further. There are also new BMS's which combine active balancing with the high current/low voltage shut off functions. They are sweet.
@@MrSummitville I so agree- I have had it happen on ebikes when I have been a long long way from home. Had to open the battery and bypass the BMS with a jumper.
Shawn should I set my cut off at 28v or 30v? I have a 36v 14ah battery. And one of the things my new LCD throttle controler ask is what low volt shut off to set at. Thanks.
Who the fuck asked about your health and your life, stop projecting and get on with your life. My girl died of a brain tumor , but I don`t shout and yell about it because some internet RANDO said something about being a MAN.. Shut up, play nice, get well soon, and don`t forget to take your testosterone pills.. ffs..
Hi Shawn, I am going to make a lifepo4 battery pack 43.2v 20ah. My charger is a Grin Cycle Satiator is it possible to charge the hole batterypack without BMS, or do i have to split it up?
Max voltage per cell is 3.6 so you must have a 12S Battery. The largest commonly available Hobby Charger is a 10S, so the pack would have to be split or you could use my BabyBloc Balancers on my BatteryBlocs website, or you will need a BMS.
So glad I found this Video. Working on a Chinese 100w scooter and swapping the Lead Acid battery with 18650's. This was really helpful because I had the same thought. I wanna know what my cells are doing and not just let happen till it fails. So thank you for this detailed explanation why not to use a BMS and what alternatives there are.
Thanks Hard Disk lover, This is a common conversion. The Lithium Ion batteries tend not to have the punch- the ability to dump amps- as the lead acid, but they go further...
Hi Shawn I’m goin to go back to my 14s5p kit but link it together in 3 like 6s5p x2 plus 2p so can balance on my imax b6im not payin 150 to 200£ for i10 charger waiting for new bms replacement but can’t find anything wrong with my wiring last time it smoked ?
Thanks for this Shawn I've explained this to many after watching your video a good while ago. I'll be creating 4x29V packs @26AH. Connecting 2 in series & then paralleling. creating a 58.8V @52AH With cell logging like yours & also adding foldable solar panels to the bike. I have a 48V 1000W rear hub on a dual suspension, 300+ new cells. I'm just waiting for my spot welder to arrive which should be pretty soon! Excellent video.
Thanks Shawn. Coming from an rc background I didn't like the sound of these BMS units. You verified my thoughts and I will be using your charging method on my diy batteries. Full control and monitoring of the charge is the way to go. Hobby chargers have gotten so inexpensive too. Cheers
Hi, thanks for this informative video, I learned a lot! Can you tell me if theres a form of cell logger that cuts off the battery when it detects low voltage (maybe instead of the buzzer). I am building a music box and four 4s4p packs. I want to build them without BMS, but i need an automatic shutoff, because I wont hear the buzzer over the loud music. I also got an original IMAX B6AC V2 Charger, do you think thats okay for my use? Greetings from Germany! 🙏🏽
Hi Vivian, Hmm, I have used an over/under voltage relay--- Here is the link: www.aliexpress.com/item/32826508821.html?spm=a2g0s.9042311.0.0.27424c4dwH3n6D But it monitors the overall battery voltage, not the voltage of each parallel group. You could also use a BMS just for the low voltage shutoff- along with your iMax. You can use them together- Replace the buzzer on the cell logger with an LED light? Keep an eye on a voltage gauge for each battery?? Ahh, here is my worst idea- play the music softly! cheers, Shawn
@@shawname2 Hi Shawn, thanks a lot for your ideas and your fast reply! I thought about using a bms only for the shutoff (just like you said) but I wasn't sure if I could still use the balance charger. So I decided not to use a BMS, also because I would have to buy 4 pieces and I'm afraid they could burn down or otherwise ruin my battery packs. Therefore I will put a cell logger in the musicbox and add a switch, to be able to turn it off, so i can sometimes check it throughout the day. I will also use a module that shuts off when detecting undervoltage (of the whole battery). It's just there in case I forget to check the logger after three days of partying... :D It's a bit cheaper than your relay, i hope it will work correctly: www.banggood.com/15A-DC-6-30V-Lead-acid-NiMH-LiFePO4-Li-ION-Li-PO-LiFe-Polymer-Lithium-Battery-Discharge-Protection-Board-Module-PS9DC01-p-1625430.html?rmmds=myorder&cur_warehouse=CN The soft music thing wont work, but Ill try to keep an eye (i think the other eye needs to be closed) on the cell logger... ;-) I like your type of humor, hope you`ll do some more videos soon! Thanks a lot! Prost (cheers), Vivian
Hi. Please can you tell me where I can get those battery holders with magnets. Thank you very much and I’m looking forward to hearing from you. Kind of Florin
Very well thought and explained. Thank you for that. I lost my innocence a while ago when I initially understood what a BMS actually does. You stated it clearly: It cuts the load for the WHOLE pack when ONE cell hits the ceiling and it cuts power from ALL cells when ONE cell hits the floor. Well what is this? I once worked with financial auditing guys. They shut your business down when you don't behave. That's why I'd call it a battery auditig system rather than a management system. But what's the solution? I'm an RV guy and I wouldn't prefer taking out my battery and hooking it up to a seperate charger when one of the cell loggers barks alarm. Again thank you for that, these cell loggers are THE concept to keep yourself in charge (pun intended). I'll have to let that sink in but you already have me disassembling the pack in my car and replacing the BMS for something that makes sense.
Hah, funny. The solution for your RV are active balancers. They will move the power from the high to the low cells. You can use this and your BMS- as they do different things. One of these goes on each parallel group: www.aliexpress.com/item/4000110143557.html?spm=a2g0o.productlist.0.0.262e1a573VZZUj&algo_pvid=82dd80a6-a20d-43a5-81e8-4cb827d5f3dd&algo_expid=82dd80a6-a20d-43a5-81e8-4cb827d5f3dd-28&btsid=0b0a556a16118734480406241edf1a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
@@shawname2 you know what? When I look at the whole market and what's being offered as extra gadgets (and we did not need any of them in lead-acid battery times), I start to suspect that some of this might actually be snake-oil. I'll start by glueing some of your cell monitors to my co-pilot seat and learn from there. Thanks again for the kick in the ass!
How about programming a VESC or ESC to in place of a BMS and use the BMS only to charge the battery by passing the discharge rate? Is there a battery balance charger that can balance charge 10S or 12S batteries? I've only found balance chargers for up to 6S.
Totally agree I had a battery that didnt have capacity. The problem was it become unbalanced, and after I balanced it, the battery was good again. Thank you alot
I spoke of using step down modules that i can use to charge each cell individually rather than use a balance charger but thats a lot of plugs to connect when you have a 16S pack. However you don't need to balance charge each time. I usually balance charge every 3 or 4 discharges. Otherwise i charge at full voltage of all of the cells in series. Then it's only one connector to plug in.
the vruzend guy says I n eed bms also the nkon supplier of the cells too.i beefed up the wiring after first run so I'm not sure now.when first run the batteries were not at full charge.but after bulk charging the green light came on the charger but still not up to 4.2v but u suggest say up to 4.v okay shawn?thanks.steve in uk
Even the hobby chargers are not really a match when you get very high numbers of cells in parallel. I had one battery that I was testing for a golf cart and it was 10s 100p. I ended up splitting each parallel pack into 1S and then charging all 10 series packs in parallel, from a 300 amp 5v PSU that I turned the trim pot down on until it reached 4.1v. A full charge takes 7-8 hours but I rarely need to give it a full charge.
Yes, they are no match for power walls or other high amp hour packs. Multiple small power supplies set to 4 volts could be used to balance. Or the battery could be bulk charged and a voltage activated relay could turn on a resistor to pull down high parallel groups....
Excellent video/explanation !! I was also getting frustrated by the poor performance of these small BMS boards and came up with a solution that uses same pieces of your approach. Still keeping the BMS, a put 2 JST connectors the the battery case where I can check once in a while the state of the battery and if needed rebalance with a balance charger. Disadvantage is that I have to dismount the battery case for that. And I still have to see if I can lower the voltage of the main charger. Did you find any real JST sockets or did you use the standard PCB versions glued into a corresponding hole, like I did?
Great approach! I did find some double ended jst-xh connectors, though I don't remember where, it was a radio control hobby shop online. If you can open the charger, there is usually an adjustable POT near the DC ouput that allows for tuning of the voltage. Steel cased chargers can be opened... cheers, Shawn
I like the way you think about modularity. The great cost for DIY EVs is the battery pack that gets luxuriously expensive when it gets bigger. The smaller packs are produced in quantity and get cheap. It's important to keep it safe though. You sound like you know what you're doing and I just wanted to reinforce to random viewers to know the risks and what to do exactly before attempting this. It looks like good BMSs talk RS232 and other protocols to communicate the monitored values (individual cell voltage and more) or even be programmed/setup. One could use that to talk to a microcontroller and display whatever is needed. These days there's Arduino enabling this for most people with time to spend on it. Not OOTB, I agree. Or just hookup the "trouble bit" to a dash LED and have the microcontroller/laptop setup at home for debugging. Not better or worse than the "Engine light" + OBD devices on gas cars. I like the hobby charger approach as it's pretty safe but I'm at 16S and it already got somewhat cumbersome to manage daily charges. I made a 16 Ah pack out of Multistar 4S bricks. Currently charging on a unbalanced charger for the whole pack, no BMS but only because the pack is new and I monitored close per cell voltage in the first 5 cycles. I'm installing a higher end BMS in the next month or 2, so when they age the BMS will shutdown if something abnormal happens and I can connect to it and see what's wrong (or check the pack manually). I made my pack removable exactly to make this sort of maintenance easy. But yeah, not too surprising that the cheap BMSs do a bad job -- we get what we pay for.
Awesome video thank you. I am new to the e bike world am working on my first build now. I'm a bigger guy and live in a town thats ALL hills so I want to make sure there is enough power to get around without over taxing the system. It first I just wanted low range (around 30 miles) but seeing what these 18650's are capable of I'm not thinking I want to be able to tow a small cart with additional batteries for a long distance trip this summer. I like that you monitor each group and you can turn them off to not draw wasted power. I dont have any experience so my concern is not knowing when to check them. can I run a bulk monitor to measure overall voltage or could I just leave these on all the time without too much of a net effect?
Hello Shawn, I have a question. If I split a 10s4p in two 5s4p batteries, like yours in the video, could I connect the two batteries and also the jst connectors in parallel and charge them at once with a smart 6s balance charger?
What would be priority for using used cells? IR or capacity. I know having capacity dictates what voltage you'll be at but I'm confused. I have a bunch of lg mh1 cells and turns out they were as great at the seller sold me on. Ive been measuring internal resistance to get a pack that's healthy but I have had issues before with making a pack out of used cells. I don't wanna give up since I've built some good packs before but those were brand new cells.
Hi Shawn, my shengmilo 1000w 48v ebike blew its BMS and the company sent me another which had also blown (the swine's sent a used BMS with old solder on). My question is can you tell me how to wire the battery to the bike without the bsm please? Its my only mode of transport to and from work. Please help.
Do you have a link to the cell monitor your using? I've been looking (for a lifepo4 version) for a bit, and I haven't found any for a reasonable price. But I also haven't found the one your using. Thanks!
Very comical but great info. I know Jehu doesn't use a BMS on his EV van so neat to confirm when you can charge responsibly without a BMS. Thank you kindly for sharing even though it was a couple years ago - just seeing it now :D
Hi . What battery configure do you have supplying your I charger . I just bought 2 1010b chargers 4 30 dollars and maybe 1 12v battery is not enough as is only 70 ah .What do you use in your inbuilt charger pack.I just bought a electric bike adjustment pack and like your reasoning but what is the effect from ripple damage from external ac sources via dc battery to li ion battery's .I see you have mains input by your helical lead to DC charger to another battery then the icharger which supply's the li ion battery's .Do you fully rectify 110v ac straight to the icharger as they must be inbuilt also. Just a question I will experiment myself as that's what it is all about. I know ripple from ac destroys a lot of battery's tho so if you know anything then please let me know.Its probably best too charge an ancillary battery first then disconnect ac and then use icharger as inbuilt system. Or you can use 110/240 v input to a rectifier unit dubiously connected to the icharger to power the li ion battery's . I trust this is not what you do. Anyway good channel ,loved your ride through the great Irish /British weather and the road layout all the small lanes omg it's a cyclists worst nightmare other than London.I grew up with peddling on the left side of the double yellow lines right next to the kerb. Yeah anymore and you had 2 be constantly looking over your shoulder for traffic cause they would never even consider giving you any room. Times have changed a lot now but roads still same in GB . Cycle in Germany if you want the best cycling trip of a lifetime in Europe and don't worry most speak English . I know live in Koln and cycling is awesome go to Dorn is most beautiful and naturalistic . Just learn a few German words instead of the normal reply of I only speak English and you will be welcomed even more so. I am a HV engineer living in Cologne and not a tout guide operator but this place is geared for cyclists more than Holland. Anyway enough said. Do you use an intermediate battery pack when charging.I would.Cheers
OK long question MOU! congratulations on your ichargers- that is a good deal! I power mine three ways. One is with a computer server power supply. The other is with a large 12 volt storage battery. The third is with a lithium ion battery charger of 24 or 36 volts. I have never had any issues with any of those methods. The ichargers are quality units and probably filter out any AC ripple. My son is remodeling a 250 year old house in Germany. I will travel there soon. Cheers.
I have also adopted the idea of a open discharge and a small blue tooth BMS to charge and monitor in real time. I agree with all the point made in this video but Am i correct to presume this video was made before bluetooth BMS's were available ? How do you feel about a blutooth BMS for charging/monitoring only now that they exist and are mostly reliable ?
They are better as they allow you to check up on the balance. The real improvement is with BMS's that have Bluetooth and active balancing and allow you to program all parameters, such as this one: www.aliexpress.com/item/1005004059807727.html?spm=a2g0o.productlist.0.0.23fe582dtbOF3b&algo_pvid=c5fa2f33-93a3-4478-bceb-97ecfe1a9e76&aem_p4p_detail=20220505081953197176857130580017968223&algo_exp_id=c5fa2f33-93a3-4478-bceb-97ecfe1a9e76-2&pdp_ext_f=%7B%22sku_id%22%3A%2212000027934652609%22%7D&pdp_npi=1%40dis%7CUSD%7C%7C166.58%7C%7C%7C%7C%7C%40210318c216517639929768262eb32c%7C12000027934652609%7Csea Cheers!
i am trying to build my first battery pack, and i am trying to make it capable of 20A for each parallel cell (so 2P = 40A). Only the series conductors need to be high amperage right? I could probably be fine with 7A nickel strips connecting in parallel, since the parallel does not see much current, right?
Hi Shawn Love your sense of sarcasm I have a 54.6v limit charger. Would I be able to limit the voltage down to 53v on a 13series pack to get 4.07v per cell and do I simply connect up the multimeter leads to the charging port of the charger?.
Yes, you should be able to. I use alligator clipped jumper cables to connect the multimeter leads to the charger XLR. The top of the metal charger case lifts off when you remove four screws. Find the tiny blue potentiometer with the gold screw and adjust while watching your multimeter. There is a limit as to how far the voltage can be adjusted, but a volt and a half should be doable.
+Shawn McCarty Thanks for that. After watching your video I will always be thinking BS when hearing you say BMS. Haha. I won't be fitting mine now. I bought a 57v limit charger and literally blue up my battery pack. Took half my Bike with engulfed in flames. Firemen weren't impressed. Now my wife has a nervous twitch every time I talk about batteries.
Yes, you should be able to. I use alligator clipped jumper cables to connect the multimeter leads to the charger XLR. The top of the metal charger case lifts off when you remove four screws. Find the tiny blue potentiometer with the gold screw and adjust while watching your multimeter. There is a limit as to how far the voltage can be adjusted, but a volt and a half should be doable.
I blew two large cells due to those crappy balance port connectors. This is my main reason for using one module for each cell, you can use better connectors. I think i am going to go this way and build a charger for my new 16Ah 16s lipo project. This way i can break down my packs into any size i want to help fit them around the frame of the bike. Also if i choose to go trials style riding i can make it into an 8s 32Ah or just use half of the battery at 8S for shorter lighter rides.
HI Shawn! wonder if you could tell me, when it comes to lithium batteries i hear so many versions how batteries should be charge, full till light indicated changes, just before it changes. what is in your opinion best to best do for batteries to last longer? thank you .
Sure. It is well established practice to charge lithium batteries to 4 volts per cell to double the cycle life Most of the charging stress takes places in the last .2 of a volt.
Hey Shawn thanks for all your advice how to set up my electric bike. Just got a new set of Batteries to solve my voltage drop cut off issue. Haven't tested out the new battery but wondered if you could tell me how to adjust the amperage power on my 4 amp 54v charger. I worked out how to reset the potentiometer for the voltage but not the amps. Cheers
Congrats on your new batteries! I don't know how to adjust the amperage on your charger. You may not need to. If your batteries are greater than 10 amp hours you should be fine.... If it's critical you could run the charger through a Drok so you can adjust the amps. I've got a video on it..
+Shawn McCarty Hi Shawn I want to expand my battery pack with a 13 x 6 parallel cell pack is it better to do this or attach another 48v pack in parallel? Thanks Robert
Hi Robert, Are you using BatteryBlocs? IF so you can connect your 13 6packs to another 13 6 packs (or any other pack) and make one large 13s12P battery. This means you could use one charger and BMS. If you have spot welded packs you will need to have two packs that you connect in parallel. There is no other simple choice....
if you wanted a bms on this too, how would a bms work with the split packs? just one 14s is needed and it'll operate when the two packs are connected in series?
im not looking at this because i want to build an Ebike like most. But i want to use lithium ion batterys for some tools and a portable radio system. But a lot off people keep yelling you cant just do it because you need a lot of electronics in the battery pack and all that bs. But you just proved to me it can be done with some simple electronics and instead use a better charger(wich is better in my opinion anyway because i would like to see what my batterys did instead of just trusting it will be fine)
Hi Shawn. Thanks for the video. Can you point me to where you bought the hobby chargers, battery monitors, and connectors you show in your video? Thanks.
Hallo, great video! I want to build a 13s4p battery pack without bms and balance charging and also monitoring it in your way. Where should i connect the fuse you are showing in the video? Is this a special fuse? Is there something else to do for safety? Thanks.
The fuse goes between the battery and the load. On an ebike that would be the controller. In the event of a short, the fuse will blow. Consider building a 14S battery instead- you can divide it into two 7S batteries and charge it as such.
The eloquence, the fine humor and people dare to say UA-cam has no good content. Not that you need my compliment, but you're good! I learned a lot.
As an Electronics Technician, with many years of field experience (yeah, old schooled in TVs, who also keeps up to date on tech) I can vouch for this excellent presentation.
I began watching the video and had to smile when you came to the point that BMSs do not provide any feedback of the state of the individual cells, therefore makes no sense to use them, specially when one cell goes whacky and the BMS shuts down everything.
Thanks for putting it together and to the people who gave negatives to the video, you guys don't know squat about LiIon batteries and basic electronics.
Thanks, I'm chuckling.
It's an old saying to "not know squat" I believe it came from the era of the paddlewheel boat captains making their way up and down the Mississippi. If you didn't know "squat", there was a good chance you would run your boat aground on a sandbar.... Is there a metaphor here?......
hah.. absolutely... those folks don't know jack shit either :-)
I rarely comment on videos but I had to this round. This was an outstanding and informative video with a very good option to an aggravating issue. I see this solution 10 fold better than pretty much all standard styles and 95% of any non-standard ideas for doing this. Love it and for sure recommend.
Thanks Drew!
Shawn
I also make a video on bms inspired by him visit my channel to watch the video. in my video you got everything about BMS
Topic cover in my video is:-
1) how bms work 2)how to choose the right BMS 3)how to connect a bms 4) how it's work 5) if BMS take care of series what about the cells that are connected in parallel
I can't say for certain, but I seem to remember some BMS units that have Bluetooth and/or WiFi commo that can do what the "loggers" do, and send the real-time data to your smartphone as you ride. They also had an alarm feature in their "app" that provided both audible and visual cues from the phone to the rider.
...and here I am talking about using an "app" when I have always warned about relying on any tech that REQUIRES an "app" to work for you...the fact there is no guaranty the "app" will be around next week and could be unilaterally removed from your phone at any moment without warning (company goes out of business, stops supporting it, to continue working it requires you replace your phone with one that has a newer version of Android/iOS, etc).
Hey Shawn. Excellent video! Your approach sits really well with this retired instrument engineer with a serious DIY inclination. I can't wait to build my first battery pack and put your approach into action.
Thanks Brian!
Thanks for letting us in on this. I just went out and tried to see if my ego hedger would work with just 56v without its bms and it did. This will save me lots of money. Thank you Rocket Man
this may be the most informative lithium charging video I've come across so far. thank you
Thanks Ken! Hope it clears some of the mystery about charging Lithium chemistry batteries.
Agreed, it validates my work based on what BatteryUniversity says about prolonging lithium ion batteries via undercharging and that BMSs are an unnecessary additional point of failure.
I have an iCharger 208B for going on 10 years for my Yuba Boda Boda. I like it and use it for other projects as well.
I run LiFePo4 batteries in (2) 24 volt packs. and charge them with a 4 pole double throw switch that charges the packs in parallel and runs the bike with the packs in series.
I charge at 3.5 volts per cell and after 5 years on this bike with this pack, 5 back tires, 2 chains and gear clusters. and 1 back wheel they are only .3 Amp hours below rated capacity. The darn things will never wear out so I have no excuse spending a lot of money on a pack upgrade.
No BMS.
Sacrilege, you mean low quality chinese made BMS should not be trusted to manage your expensive batteries? thats not what the internet told me
Too many people drink BMS Koolaid. Glad you enjoyed the humor!
Shawn McCarty
Yes, that is my name. Do you have a comment Dhirajlal? If so, it didn't post.
Wie wird ein BMS auf ein accu von 24 v gebaut ? Sprache bitte in deutsch
We are battery specialist from Shenzhen, China. Hope we can help you with favorable price using Panasonic cells.
Skype:elsa.chen76.
Email: elsaqant@gmail.com
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Really glad I found this video before I build my pack. I've gone BMSless and have no regrets so far (300 miles of riding so far, and ZERO Balancing needed using 280 used laptop 18650s). I'm waiting for a little 8s voltage display that cycles through the voltages of each series, it cost me a $1, that's the kind of feedback I want.
Yes, once you learn how to go without a BMS you don't want to go back. A BMS is kinda like training wheels for batteries.
On behalf of everyone involved in 18650 cells THANK YOU sir
Completely agree with this approach, needs a wider audience.
Thank you very much sir. I'm glad that there are people like you in this harsh world we live in. I wouldn't have ever known this if it wasn't for you.
Glad I stumbled upon this. As a “newbie” to this stuff, I couldn’t understand why BMS’ are held in such high regard when 90% of the reclaimed cells I have so far are good cells and bad BMS’ (it seems). My logical brain said “wait! what about safety!” But when I heard the little alarm go off? A little alarm went off in my head. I want to be in control, not a nameless, faceless (silent) BMS. Visions of exploding LiOns ...umm..exploded lol. Bravo! As I tell my customers, “ I like my smart devices to be smart when I want them to be...and very dumb when I want them to be. “ Your approach seems logical. Great stuff and pretty funny too lol.
Good video. I've found that battery packs last better when cells are in parallel as the cells keep each other balanced. I use 3x 4S4P in series for a 12S 20Ah pack without a BMS. I can split them at anytime for hobby charging but prefer to bulk charge using a constant current 10A LED driver with Max voltage set so that cells do not exceed ~4.1v. I occasionally balance each 4S4P pack separately using hobby balancer. The 4P setup keeps them very well balanced.
If this is indeed more efficient / better balance and longevity why don't battery pack companies and DIY's build their batteries in this manner as you described?
@@connicrow9463 @Conni Crow they do, except they always add a BMS due to the nature of lithium batteries. I was confident on my pack because the sense wires (also paralleled) were very small therefore naturally limited current (like fuse wire). I did end up losing multiple paralleled cells when one went bad, but this is normal in any pack. BTW, as proof, my current bought battery is 13S(7P) compared to the long gone homemade 22S(4P) - I now have BMS security(cell charge limits; cell balancing which really is required as every cells different)
@@MadMatty72 in other words, you got lazy and used a bms. I've been there haha.
Great video Shawn, I made an ebike last year using 10 x 6S 5Ah lipos to make a 48V 12S 26Ah pack and don't use a BMS.
I charge using a Turnigy Reaktor 300W 6S charger in two sessions, and as often as possible from 300 W of home made portable solar panels, that weigh about 6 lbs, fit in a backpack and can be laid out anywhere.
The pack is capable of giving 12kW of power, though I "only" use about 1.5kW, and that is plenty!
I just made a couple of extra cells using 16 18650s per cell (~36Ah each) so it can cope with 30A and 50A burst regen, and now gives me 14S, though regen doesn't work until the voltage drops 1/2 an S, as I found out when I needed to brake the first time I tested it!
Yes, I know the chemistries are different, but I charge them individually and make sure voltages are always within spec.
(Just a note about XT60s / XT90s - lipos use the female type, so I'd recommend following that convention for compatibility).
(I put a video up showing my pack, charger and solar panels on my channel if you're interested)
Hey Shawn, great to see someone accurately describe those Battery Murdering Systems!
One thing I would suggest though...you can reduce the effort involved in bulk + balance charging like this by just using a balance tap only charger like the BC168. Yes the balance leads/plugs are somewhat limited in current carrying capacity, but if you limit the charge rate to something reasonable it can and does work. I've been doing it like this for over 4 years now.
Cheers
Any recommendations as to which hobby charger I should get?
Vince, I'm fond of the i-chargers.
@@shawname2 thank you!
I watched your video 10 times and I rephrased my question again.
1. I'm planning to build my first battery pack and convert to ebike, and you convinced me to spend more on good smart charger.
I looked up iCharger 1010B+ but max output V 40 with 7 A, so by charging not to 42V but 40 V , I will extend my battery life.
Please confirm that 1010B+ charger will be good for 36V 15 amp pack. What power supply would you recommend for this charger? I found Junsi 350 - Outputting 350W at 23A/15V. Will it be good?
2. If I get 10S charger but cell logger can only take up to 8s, can I connect 2 loggers 5 s+ 5s (not physically splitting the battery?????) and have extra port with JST-XH 10s for my 10s charger so I can charger my my 10s5p battery as one?
3. Mr. Jehugarcia, talks about bottom levering batteries, should I then go up on the charger and get PowerLab 8 to do both smart charging and bottom levering of the batteries??
Thank you a lot!
sir, you have no idear how much knowledge you have, please share it with the world, we thank you for.
Thanks Shawn for this great video! I'm now convinced to use a hobby charger to charge my ebike and no longer rely on a BMS. The only small "issue" I see is with the cell logger: this thing will be powered from a single cell and so it could slightly drain that cell compared to the others, thus generating imbalance... Is that a problem in practice? Or are there any cheap cell loggers that are powered from each cell one at a time? Thanks!
I have been using this method since 2017 on all my battery packs on all my ebikes. Thanks Shawn. I've seen some comments about a newer type of BMS that replaces the need for this method of charging. If you are one of those persons please point me to a BMS that can limit a charge to 80% and balance at 80% as well. Ive seen bluetooth BMSs and have had one in the past but couldn't see how i could limit the charge to 80% and have it balance all at the same time. Thanks for any replies or links.
Hey Shawn, this is the BEST anti-BMS video I have watched so far!!! I don't use BMS myself for the same reason as you, there's no feedback and I don't know what that little cheap and nasty PCB is doing. Most batteries (to not say all batteries) I repair have a problem related to a faulty BMS. The cheap ones don't balance the cells at all they actually KILL cells.. last thing you want is "a device that will unbalance and kill your battery". BMS also makes things unnecessarily a LOT more complex, that doesn't encourage people to make their own batteries!
I made a pack with Panasonic PF back in 2014 and last time I balanced was almost a year ago, I run it hard 1500w every single day, guess what, almost one year later the pack still balanced.
On the other hand I have many videos showing "how to install BMS" because from a bike shop perspective, most ebike users have absolutely no clue about electronics so in this case the BMS is more reliable than some humans.
Congrats for this video, I will recommend to many people here when replying comments in my channel =]
Hey Thanks Bruno! I'm pleased that you have come to the same conclusions that I have. Tell me, how far would you let your pack get out of balance? .1 volt, .2 volts? And what cell voltage do you charge to to be safe- 4 volts?
Hey Shawn, good questions haha.. at work I have to be a bit more strict with balancing as the pack wont be under any monitoring apart from the BMS, most BMS will cut above 0.5v so I try to keep it below 0.2v after multiple cycles to ensure this difference is not growing and the pack is stable.
I do charge my 14s all the way up to 58.8v which is 4.2v per cell, it takes a LOT longer to charge but in my case I performance is more important than range and the pack life. For a regular commuter I would say 4v per cell is all they need, really liked you mentioned many times in your video that charging to 4v you can double or triple the cell life, most people don't even know these things. POWER to the people haha =]
Thanks for your insights Bruno! Experience has led us to the same conclusions!
No bms also gives you more POWERR!!!!!
Good point. It's because the power does not have to run through the circuitry of the BMS.
i've been thinking about this for most of the day today. it must be possible without the BMS. ZACK! now I have seen you....many thanks and greetings from germany
Agree 100%. Your battery is only as good as its lowest capacity block. Once it is full, charging should stop.
There is no point in putting more charge into any other block, its just a waste.
My Idea is to monitor and display each block voltage and auto disconnect the charger when any block reaches 4.2 volts.
Less if you only want to charge to 80%, to lengthen battery life as with Tesla.
Likewise turn of the load when any block is down to around 3 volts.
To really balance a pack it is best to make sure each pack has the same Ah capacity.
Thank you, this is exactly what I was looking for. I suspected that the tiny resistors on a BMS were not capable of applying enough drain to actually balance the batteries. There's a reason the hobby chargers need fans to stay cool, and that's because they're dissipating off more energy as heat to actually balance the packs. I also really appreciate you showing how you wire the batteries to split them for charging as 2x 7S instead of one 14S. Hopefully now with EVs becoming more common, larger and better chargers will become available for charging 12S - 16S packs used in EV setups.
I hope so too, but I won't hope for long. If one isn't out let's build it!
Hey Shawn, thanks for the awesome vid. Making all my packs with this info now and it's making a huge difference! Thanks again Shawn!
just a quick update. I have assembled the pack using your method of no bms. still waiting on the new volt checkers as the first type are a waste of time. balance charged the pack to 4.1 volt traveled approx 50 km and stop to check voltage on cells from time to time. they haven't drifted at all. bulk charging now and will monitor every 30 min. thank you so much. you have been a great help.
Hi Which volt checkers did you find best ? (link)
_lh3.googleusercontent.com/tUh95SS7i1GXyEjz3NPcq5ROzm6Qg6rY1uFvxRX8NNaqTx0rpcsfJqGMRvyJIYvdwTo2vgsP_
I will look to see the seller's details and let you know
That's great Antonio! I love it when someone actually builds one of these packs. You can use the over voltage alarm on the cell checkers so you don't have to physically watch the packs....
Any link/manufacture for the preferred Cell Checker supplier Shawn ?
I hate to be the one to say this, but this isn't really practical. You can easily buy a Smart BMS with Bluetooth which can monitor the cells which makes all this clever engineering obsolete. I'm not saying this won't work, but it is a freaking hassle and if you don't hear those voltage sensors beep, (I have several of those) your really in for it. You don't even mention a battery monitor to which you can look at from the handlebars, I'd have to get off my bike every 30 mins to check where my battery is.
Thank you for taking the time to put together such a non BS video. anytime I am told I have to use something I ask why and if I don't get a satisfactory answer I usually find it is a lawyer insurance company or Corporation.
Please excuse my ignorance, I don't understand how the charger or logger can see individual "cells" when everything is connected together in series. Does it do the math for you and work it's way out along the chain? Could you do the same with a multi meter manually? Sorry for the dumb question, this is all new to me. Is that batter pack both parallel and series combined? 14 long in series, and 5 wide in parallel?
How does the charger target specific batteries? Does it bring everything down to the low water mark, and then charge from there hoping that everything will be even afterwards?
Great questions!
The logger or charger starts with the negative terminal of the battery. Consider that "0". Then it goes to the positive of the first cell. Consider that 4. Then it goes to the positive of the next cell, consider that 8. Then it does the math and deduces that the voltage of the 2nd cell is not really 8, it is 8-4=4. Etc.
The charger charges the entire pack in series. Using the same technique, it monitors the voltages of all the cells. If one exceeds the set limit, say 4.2 volts, it turns on a resistor through the balance lead connected to that cell, and attempts to reign it in. Failing that, it reduces the charge current. Failing that, it shuts off the charge.
Shawn McCarty thanks so much for the response!
@@shawname2 enjoyed your vdo & info, correct me if i'm wrong but in your explanation above, each voltage point being measured w/data logger is that of 5 "cells" that are in parallel, not an individual battery "cell", thus it's possible that over time you would not know if a cell or 2, etc. has opened ( out of the 5 ) and/or developed a failure mode resulting in high internal resistance ( won't take a charge/shows few millivolts).. ( by wouldn't know i mean other than your range would be lower...pack produces less amps, etc. )
Good comment. Yes, it does the math and works its way out along the chain. You could do the same with a multimeter or a voltmeter hooked to each parallel group. Yes, all batteries are made up of cells connected in parallel to multiply amps, then those parallel groups connected in series to multiply voltage.
@@robozstarrr8930 yes, i thought that too, it's a disadvantage of the parallel/series system as opposed to the series/parallel. In the latter it's much easier to determine your bad cell, but seemingly the advantages of parallel/serial outweigh this disadvantage
please, tell me more about 17:30 calculation!
supposing one 7s pack, if I use a constant voltage power supply of 28V instead of 30VDC or more, the BMS cannot charge at 4.2V per cell, stop charging each at 4.0V and the number of cycles increase a lot ? of course the mileage full at 4.0V for each charge is a little less than the pack with 4.2V but a lot more cycles are really good.
4.0v saturated cells are 80% charged. If that is not enough range then better to add more cells than to charge to 4.2v which stresses the cells and saturation cutoff is critical.
I agree, and when there is room. But it is good to have the option of still being able to charge to 4.2 in case you need the extra capacity for a long long ride.
It is good for a knowledgeable human to make that choice, not a chip!
I confirmed your conclusions the hard way. After failed bms after another, was heading back to the Imax. I will be splitting my 10s packs into 2-5s. Thanks!
Sorry Bob- I wish it wasn't so. But consider springing for the icharger that does 10S- so you don't have to split your pack.
cell logger is a great idea but only handles 8s max? Suggestions are appreciated. Have your tried a smart bms?
cool. putting 2-5s cables on the existing 10s allowed the cell loggers and balance cables to work as 2-5s while not having to split the 10s. Cool
Watching this in 2019.
Now you can get BMS with bluetooth and monitor cells(ebay and aliexpress from china)
I'm going to assume that the BMS intended for 300 amp charge/discharge is going to have enough balancing capacity to handle an ebike no problem. There is stil the issue of the BMS cutting power mid-ride if it finds low voltage. Price is around 120 USD from china. I am waiting for mine to arrive. I hope it works well. They come with a flat aluminum plate as head sink on both sides of circuit because there are mosfets to pass current on both sides of the board. I will be mounting finned aluminum heatsinks using thermal conducting tape to both sides to keep the board cool. Solves a lot of complication, hopefully it works well and reliably.
Thanks for reading.
Let's see how that works out. Times change! I'd love to have a really simple balancing solution for ebikes. Now I use active balancing on the power walls, that is working out well.
I agree completely with you, before I found this video I have been struggling with small BMS to use on small battery packs, so far all that has happened is that I have managed to ruin far too many batteries. I know it is a long time since you did this video, but I would love if you could direct me to the cell logger you show or something like it. I like that it just does one job. Many thanks in advance.
www.amazon.com/4Pack-LiPo-Battery-Checker-Indicator/dp/B07VNW4MXL/ref=asc_df_B07VNW4MXL/?tag=hyprod-20&linkCode=df0&hvadid=366306819795&hvpos=&hvnetw=g&hvrand=12867851692344477874&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002830&hvtargid=pla-802176963546&psc=1&tag=&ref=&adgrpid=81881572248&hvpone=&hvptwo=&hvadid=366306819795&hvpos=&hvnetw=g&hvrand=12867851692344477874&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002830&hvtargid=pla-802176963546
Ok, so just to be sure: you can ''bulk charge both at the same time'' meaning you use the balance charger in another setting in order to charge? And then, when you want to balance charge, you separate the 2 packs and then charge them one at a time (assuming you have only 1 charger)? Thumbs up perhaps so people can see.
YEs, that is it. But you can bulk charge to extend the life of the battery by keeping them connected together and charging both at once. Either with the balance charger- not in balance mode- or a separate charger.
I'll be better charge it at pararel if I only have one charge and leave it charge with alarm on :D
Is an inexpensive cell monitor (cell auger) similar to the one featured in the video available today? Very informative video. Thank you
can I buy a 24volt 30 amp + battery from you? how much would it cost?
Awesome stuff bro...my battery tipped over and hit the concrete, I couldn't fault any cells so bypassed the bms...better power now and I just keep an eye on the cells after every 5 rides
I put and inline fuse on my bbshd build that's enough safety for me
What about if i use different brand cells in 16s10+p pack ? still dont need a bms ?
Does this still apply to today’s cells? I have two 52v 20ah in parallel with a 80a controller 3000w hub. Will it blow? So, should I bypass bms? You explained this bms thing perfectly, thanks
when you adjusted the voltage your hand covered it, any way you can re-record it with a better view please.
sir, you are a legend. keep up the work. so funny to watch you fiddle around. indeed hd quality vids has no chance on you
"tripple the life of a pack with a bms" this assumes all bms use the same balancing methods... they dont. "a better battery pack with out a bms" False. If you take the time to select the right components for your build ..and go down the path of an active balancing/charge redistributing bms... it will be better in any objective measurement of "betterness" you wish for two packs to be compared.
The guy made his case with some products and useful info. Can you share some products and examples?
GENUINE question because I have a 52v 20amp battery that I recently experienced issues with ... guess what it was?
OOOOOOH ya, the stupid junk BMS. the battery was reading ~28v and when I checked it before the BMS it read a fully charged 58.6v
@@atefamriche9531 linear Technologies. You probably need to make a circuit board but you can do things like active balancing during run time or in other words cell groups prop up a weak cell on the fly
Thank you for making this video, there is a lot of conflicting information out here. I have a first generation fiido T-1 and it's replacement less battery. I put battery in replacement and immediately noticed battery discharged faster so I ordered a 48v
advanced 300w Luna charger w/ 80 90 100 % settings charging to 54.6v @ 100% now 13 mo. old full is + or - 52v it varies each time. Now I understand why, unbalanced. Bike was shipped to me without user manual or the download. Took 4 months to learn full charging shortens battery life. Guido recommends full charge after EVERY ride.
It is good to let the battery sit on the charger and charge fully and slowly, every few months as it gives the BMS a chance to balance the battery. It will only begin balancing when a cell hits 4.2 volts... But not every time, or the battery will not last as long...... Sounds like you have it figured out!
I've gotten in the habit of charging to 90% at 1 amp. Is this a good habit?
FYI, BMS = Bristol-Meyers Squibb. Oh, wait, it is Benicia Middle School. Perhaps Blue Mountain State?
Perhaps Battery Mismanagement System?
Is sad i found this comment. I had to google myself to find the definition...
When someone uses insider language outsiders won't understand.
Hello, Shawn. I
I have a iCharger x8. Want to set up its charging
capabilities. The pins start with negative on the left. ( 10 pins ) . In your video you don't say exactly
how many positive wires connect. On this 52v 21ah battery of mine, all the wires are hooked negative.
I observed your positive wires and the next 3 positives. But I can't determine the exact cadence
of positives and negatives of your battery when I have 12 batteries to a cell. And your spot soldering
starts between the actual top of the batteries. I don't have a cell logger . Hooking up right to the charger. Oh , empire of squat-ness, I need advice
Took me a while to find a "cell logger". For anyone else like me they're called Lipo Voltage Monitor.
What are the cables to this monitor called on ebay?
aaaarneaaaarne JST-XH Connectors
thanks!
Danny Tillotson thanks for the info, I couldn't find them and hoped that someone here would give some clue as to where l could find them. 👍
www.banggood.com/10PCS-9Pin-8S-Terminal-Wire-Balance-Charger-MaleFemale-JST-XH-Connector-Wire-p-1050139.html?rmmds=search&cur_warehouse=CN
Very informative. I have built a 7s8p and 7s10p li-ion packs for my scooter with brushed DC motor. Because I need a 12v source for the turn lights, alarm and other electronics. How will I make the center tap and split? 3 and half S each or 4s and 3s or 4s each? If 4s'es each there's no 24v standard charger for it. Thank you.
This is an interesting concept! I learned a bunch from your video - Do you think this would work on something like my build on my page? Thanks
-Kage
An electric longboard? Cool. Yes, it would work. The builder would learn about how to build batteries too.
One of the cells was 4.2v maybe the weak one like you said as charges faster some just 3.9 this a big discrepancy so my cells in parallel rows of 5 if I use a 12 volt light on that row or maybe a group of 3 ?=12v will that be ok to balance charge?
"Stay within a 100drths of a volt whether you have a BMS or not"..COMPLETELY untru. As a matter of fact the higher amperage you draw the more they will vary in voltage as they are discharged.
"If your battery is perfect you dont need a BMS"..lol..what?..I make battery packs and use Panasonic NCR18650PF cells and I can tell you that after drawing 50 amps of discharge (burst) and an average of 25 amps continuous, they ABSOLUTELY do vary in their voltage and without a BMS the weaker ones in Parallel would hit 4.2 volts first and then get overcharged. Here's a hint; not all cells even quality ones are created equal!!.
Of course the problem with using a hobby charger for balancing is that on the discharge side, the weaker cells will hit 3 volts first while others are at 3.3 or higher, and if you think that doesnt happen, then you have NO real experience working with these cells, and in my opinion this video is very dangerous.
OK! Did I say a hundredths? Let me correct myself then. I balance when my batteries are 2/10ths of a volt out. "If your battery pack is perfect you don't need a BMS" is a thought experiment, perhaps I am wrong to assume everyone knows that everyone knows that no battery is "perfect"- or to be more precise, stays perfectly in balance.
Using the hobby charger for balancing and monitoring the cell voltages with cell loggers to know when your cell hits a pre-programmed low like I advocate is tried and true in the hobby industry. They run very high C packs without BMS's using this technique. The battery packs on my ebike are still working very well after over 20,000 miles and four years using this technique. It takes me overnight to come within three hundredths of a volt balance using my hobby charger, an icharger B-10, and I know this exactly, there is no guessing . I bulk charge to four volts normally and balance charge about once a month.
Thank you for your passion! I think we both care a lot about batteries!
Thanks for the reply...I didnt mean to come off sounding so snubbish...and yes we both have a passion for this..I make and sell battery packs and almost all unfortunately, have to be installed with a BMS. I have gone through many and there are good ones and there are bad ones..I am currently using Supower BMS units and they have so far been ok. Bestech have been terrible for reliability. I personally have used battery medics for my headway 24 s pack, but that's me and not many could do it...I sold the remainder of my headways to a customer and he wanted to do his own balancing but couldnt do it even after I balanced the cells to begin with. Im not saying it cant be done but most cannot ;)
Hey John,
Wish we were in the same neighborhood so we could compare notes. I am sure I could learn a lot from you. Thank you for your courtesy.
Not a problem at all. I also checked out your kits for building battery packs using magnets. I would wonder how much resistance one would expect connecting cells in this manner..of course when building a pack you want to eliminate as much resistance as you can to have the best performing pack you can make.
I agree. I overcome with mass- by building a very large conductor- the higher resistance of 1010 steel. The steel is also zinc plated- which conducts about as well as nickel. Also the distances are very short. This was of course very much in my thoughts when designing BatteryBlocs. All I can say is in practical use the steel does not seem to be an issue. If you have a way of measuring resistance very precisely I will send you some sample Blocs and you can report back.
Hi just been down on electric bike 48v1000watt one was goin ok up hill then power went down some faint lights on throttle display .peddled home checked battery still 54.8 v it’s a48v motor and controller is that ok ?must be controller I hope will check motor after 😀
As someone with a electronics and communications degree Please do not and i repeat DO NOT make one of these on anything bigger then a 4 blade drone. The issues and DANGERS are very real on any none BMS pack after a certain size.
Thanks. I always go with "respect your LiPos". The fire test videos are pretty inspiring. I think the author's approach works fine for small packs but it starts to get harder to manage over a number of cells.
Samir Yeah i agree but the cell he is working is way to big and could easily short out, my quadcopter has 26 amps in storage to use and if i did what this guy is doing it would burn my house down or kill me in the process.
I shorted a 5 * 12V Lead Acid pack (40 Ah) once and the flash blinded me for a few seconds, took a piece off my plier. To this day I thank god it wasn't LiPo.
And I think that every LiPo pack, BMS or not should have a fuse in series to make sure that stuff like that doesn't happen. I was working on the stock charging circuit that was unprotected from factory.
Yeah i work with 2x110 volt battery banks about 2 times a week on faults and issues these things can pull 100 amps in a split sec if you are in the way you are either dead or in hospital.
What he is doing is ok in small units but can in bigger units like the one he is playing with can cause a cell failure and if it goes into meltdown as i call it it's a chain reaction nothing can stop it. Perfect example if this fool gets hit by a car and is stuck under the front of the car and the batteries short out and the bike is on him it's over he will be burned very badly or killed. THIS IS WHY tesla have 6 amp micro fuse on each battery.
.
Having a micro fuse on each cell is a great idea. But no ebike or hobby packs have that technology. Yes the bigger the packs are the more power they have the more potential energy they have- to power your device or if they get crushed--- to have a thermal runaway. Same is true of gas tanks. If you are going to make batteries or internal combustion engines or hydrogen fuel cells know the risks.
I would put money down this guy is right, you don't NEED a BMS, but I am cringing thinking about the number of wires on any of his bikes. A quality BMS could be used with one of the battery log devices to keep the feedback loop.
Absolutely deserves a thumbs up for the video and for leaving an email address! Nice work, great video!
This is a good comment. Yes, a quality BMS with good parallel group monitoring is a good solution. A toggle switch is wired into the negative of the cell monitor. A two to one splitter on the JST wire harness reduces the number of wires. A BMS bypass switch could be used if the BMS shuts off the battery but you still want to go a little further. There are also new BMS's which combine active balancing with the high current/low voltage shut off functions. They are sweet.
@@shawname2 Also, the BMS can FAIL ... catastrophically ... when you are far from home.
@@MrSummitville I so agree- I have had it happen on ebikes when I have been a long long way from home. Had to open the battery and bypass the BMS with a jumper.
Battery Murder System
"Wroooong" *Trump like voice*
@@NonnofYobiznes Trump is Gone, and so is 2016 :'(
Interesting video!
Is it not possible to solder both BMS and LCD screen like it shows in the video to the same package?
Thanks
your I-charger cost more than the battery.
Chargers are 15$ imax ezpz
Shawn should I set my cut off at 28v or 30v? I have a 36v 14ah battery. And one of the things my new LCD throttle controler ask is what low volt shut off to set at. Thanks.
LOL i use to want to build an ebike but all this catty bullshit just made realize I'd rather die a man who still rode his fucking bike
dude
chill
At no point was he talking shit about sick people.
lol
well that escalated quickly :D
You could never afford an e bike,do they even make them in 3rd world country's
Who the fuck asked about your health and your life, stop projecting and get on with your life.
My girl died of a brain tumor , but I don`t shout and yell about it because some internet RANDO said something about being a MAN..
Shut up, play nice, get well soon, and don`t forget to take your testosterone pills..
ffs..
Hi Shawn,
I am going to make a lifepo4 battery pack 43.2v 20ah.
My charger is a Grin Cycle Satiator is it possible to charge the hole batterypack without BMS, or do i have to split it up?
Max voltage per cell is 3.6 so you must have a 12S Battery. The largest commonly available Hobby Charger is a 10S, so the pack would have to be split or you could use my BabyBloc Balancers on my BatteryBlocs website, or you will need a BMS.
I've noticed that people who smoke a lot of dope all act the same.
rob, yeah they a pack of enlightened dumasses
So glad I found this Video. Working on a Chinese 100w scooter and swapping the Lead Acid battery with 18650's. This was really helpful because I had the same thought. I wanna know what my cells are doing and not just let happen till it fails. So thank you for this detailed explanation why not to use a BMS and what alternatives there are.
Thanks Hard Disk lover, This is a common conversion. The Lithium Ion batteries tend not to have the punch- the ability to dump amps- as the lead acid, but they go further...
Hi Shawn I’m goin to go back to my 14s5p kit but link it together in 3 like 6s5p x2 plus 2p so can balance on my imax b6im not payin 150 to 200£ for i10 charger waiting for new bms replacement but can’t find anything wrong with my wiring last time it smoked ?
Would it be better to charge with a timer or at a lower amperage to give cheap bms more time to discharge.
Thanks for this Shawn I've explained this to many after watching your video a good while ago. I'll be creating 4x29V packs @26AH. Connecting 2 in series & then paralleling. creating a 58.8V @52AH With cell logging like yours & also adding foldable solar panels to the bike. I have a 48V 1000W rear hub on a dual suspension, 300+ new cells. I'm just waiting for my spot welder to arrive which should be pretty soon! Excellent video.
Thanks Shawn. Coming from an rc background I didn't like the sound of these BMS units. You verified my thoughts and I will be using your charging method on my diy batteries. Full control and monitoring of the charge is the way to go. Hobby chargers have gotten so inexpensive too. Cheers
Hi,
thanks for this informative video, I learned a lot!
Can you tell me if theres a form of cell logger that cuts off the battery when it detects low voltage (maybe instead of the buzzer).
I am building a music box and four 4s4p packs. I want to build them without BMS, but i need an automatic shutoff, because I wont hear the buzzer over the loud music.
I also got an original IMAX B6AC V2 Charger, do you think thats okay for my use?
Greetings from Germany!
🙏🏽
Hi Vivian,
Hmm, I have used an over/under voltage relay--- Here is the link:
www.aliexpress.com/item/32826508821.html?spm=a2g0s.9042311.0.0.27424c4dwH3n6D
But it monitors the overall battery voltage, not the voltage of each parallel group.
You could also use a BMS just for the low voltage shutoff- along with your iMax. You can use them together-
Replace the buzzer on the cell logger with an LED light? Keep an eye on a voltage gauge for each battery??
Ahh, here is my worst idea- play the music softly!
cheers,
Shawn
@@shawname2
Hi Shawn,
thanks a lot for your ideas and your fast reply!
I thought about using a bms only for the shutoff (just like you said) but I wasn't sure if I could still use the balance charger.
So I decided not to use a BMS, also because I would have to buy 4 pieces and I'm afraid they could burn down or otherwise ruin my battery packs.
Therefore I will put a cell logger in the musicbox and add a switch, to be able to turn it off, so i can sometimes check it throughout the day.
I will also use a module that shuts off when detecting undervoltage (of the whole battery).
It's just there in case I forget to check the logger after three days of partying... :D
It's a bit cheaper than your relay, i hope it will work correctly:
www.banggood.com/15A-DC-6-30V-Lead-acid-NiMH-LiFePO4-Li-ION-Li-PO-LiFe-Polymer-Lithium-Battery-Discharge-Protection-Board-Module-PS9DC01-p-1625430.html?rmmds=myorder&cur_warehouse=CN
The soft music thing wont work, but Ill try to keep an eye (i think the other eye needs to be closed) on the cell logger... ;-)
I like your type of humor, hope you`ll do some more videos soon!
Thanks a lot!
Prost (cheers),
Vivian
@@viviantennison9986 Ahh- your German. Good find on the battery protection board! Play it loud!
Hi. Please can you tell me where I can get those battery holders with magnets. Thank you very much and I’m looking forward to hearing from you. Kind of Florin
Very well thought and explained. Thank you for that. I lost my innocence a while ago when I initially understood what a BMS actually does. You stated it clearly: It cuts the load for the WHOLE pack when ONE cell hits the ceiling and it cuts power from ALL cells when ONE cell hits the floor. Well what is this? I once worked with financial auditing guys. They shut your business down when you don't behave. That's why I'd call it a battery auditig system rather than a management system. But what's the solution? I'm an RV guy and I wouldn't prefer taking out my battery and hooking it up to a seperate charger when one of the cell loggers barks alarm. Again thank you for that, these cell loggers are THE concept to keep yourself in charge (pun intended). I'll have to let that sink in but you already have me disassembling the pack in my car and replacing the BMS for something that makes sense.
Hah, funny. The solution for your RV are active balancers. They will move the power from the high to the low cells. You can use this and your BMS- as they do different things. One of these goes on each parallel group:
www.aliexpress.com/item/4000110143557.html?spm=a2g0o.productlist.0.0.262e1a573VZZUj&algo_pvid=82dd80a6-a20d-43a5-81e8-4cb827d5f3dd&algo_expid=82dd80a6-a20d-43a5-81e8-4cb827d5f3dd-28&btsid=0b0a556a16118734480406241edf1a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
@@shawname2 you know what? When I look at the whole market and what's being offered as extra gadgets (and we did not need any of them in lead-acid battery times), I start to suspect that some of this might actually be snake-oil. I'll start by glueing some of your cell monitors to my co-pilot seat and learn from there. Thanks again for the kick in the ass!
How about programming a VESC or ESC to in place of a BMS and use the BMS only to charge the battery by passing the discharge rate? Is there a battery balance charger that can balance charge 10S or 12S batteries? I've only found balance chargers for up to 6S.
Totally agree
I had a battery that didnt have capacity. The problem was it become unbalanced, and after I balanced it, the battery was good again.
Thank you alot
You are just dripping with the goods around here. Thanks for stoking the fire to the next level!
Yeah! Be bold and go for it! Just don't be stupid bold!
I spoke of using step down modules that i can use to charge each cell individually rather than use a balance charger but thats a lot of plugs to connect when you have a 16S pack. However you don't need to balance charge each time. I usually balance charge every 3 or 4 discharges. Otherwise i charge at full voltage of all of the cells in series. Then it's only one connector to plug in.
the vruzend guy says I n
eed bms also the nkon supplier of the cells too.i beefed up the wiring after first run so I'm not sure now.when first run the batteries were not at full charge.but after bulk charging the green light came on the charger but still not up to 4.2v but u suggest say up to 4.v okay shawn?thanks.steve in uk
Even the hobby chargers are not really a match when you get very high numbers of cells in parallel. I had one battery that I was testing for a golf cart and it was 10s 100p. I ended up splitting each parallel pack into 1S and then charging all 10 series packs in parallel, from a 300 amp 5v PSU that I turned the trim pot down on until it reached 4.1v. A full charge takes 7-8 hours but I rarely need to give it a full charge.
Yes, they are no match for power walls or other high amp hour packs. Multiple small power supplies set to 4 volts could be used to balance. Or the battery could be bulk charged and a voltage activated relay could turn on a resistor to pull down high parallel groups....
Excellent video/explanation !!
I was also getting frustrated by the poor performance of these small BMS boards and came up with a solution that uses same pieces of your approach.
Still keeping the BMS, a put 2 JST connectors the the battery case where I can check once in a while the state of the battery and if needed rebalance with a balance charger.
Disadvantage is that I have to dismount the battery case for that.
And I still have to see if I can lower the voltage of the main charger.
Did you find any real JST sockets or did you use the standard PCB versions glued into a corresponding hole, like I did?
Great approach! I did find some double ended jst-xh connectors, though I don't remember where, it was a radio control hobby shop online.
If you can open the charger, there is usually an adjustable POT near the DC ouput that allows for tuning of the voltage. Steel cased chargers can be opened...
cheers,
Shawn
I like the way you think about modularity. The great cost for DIY EVs is the battery pack that gets luxuriously expensive when it gets bigger. The smaller packs are produced in quantity and get cheap. It's important to keep it safe though.
You sound like you know what you're doing and I just wanted to reinforce to random viewers to know the risks and what to do exactly before attempting this.
It looks like good BMSs talk RS232 and other protocols to communicate the monitored values (individual cell voltage and more) or even be programmed/setup. One could use that to talk to a microcontroller and display whatever is needed. These days there's Arduino enabling this for most people with time to spend on it. Not OOTB, I agree.
Or just hookup the "trouble bit" to a dash LED and have the microcontroller/laptop setup at home for debugging. Not better or worse than the "Engine light" + OBD devices on gas cars.
I like the hobby charger approach as it's pretty safe but I'm at 16S and it already got somewhat cumbersome to manage daily charges. I made a 16 Ah pack out of Multistar 4S bricks.
Currently charging on a unbalanced charger for the whole pack, no BMS but only because the pack is new and I monitored close per cell voltage in the first 5 cycles.
I'm installing a higher end BMS in the next month or 2, so when they age the BMS will shutdown if something abnormal happens and I can connect to it and see what's wrong (or check the pack manually). I made my pack removable exactly to make this sort of maintenance easy.
But yeah, not too surprising that the cheap BMSs do a bad job -- we get what we pay for.
Awesome video thank you. I am new to the e bike world am working on my first build now. I'm a bigger guy and live in a town thats ALL hills so I want to make sure there is enough power to get around without over taxing the system. It first I just wanted low range (around 30 miles) but seeing what these 18650's are capable of I'm not thinking I want to be able to tow a small cart with additional batteries for a long distance trip this summer. I like that you monitor each group and you can turn them off to not draw wasted power. I dont have any experience so my concern is not knowing when to check them. can I run a bulk monitor to measure overall voltage or could I just leave these on all the time without too much of a net effect?
Hello Shawn, I have a question. If I split a 10s4p in two 5s4p batteries, like yours in the video, could I connect the two batteries and also the jst connectors in parallel and charge them at once with a smart 6s balance charger?
What would be priority for using used cells? IR or capacity. I know having capacity dictates what voltage you'll be at but I'm confused. I have a bunch of lg mh1 cells and turns out they were as great at the seller sold me on. Ive been measuring internal resistance to get a pack that's healthy but I have had issues before with making a pack out of used cells. I don't wanna give up since I've built some good packs before but those were brand new cells.
Sir can we charge the Lion 18650cells while their in use also,,just like a car or a motorcycle battery would be used.
Hello Shawn, how did you achieve to keep cell monitors off and turn them on only with the button? THANK YOU!
Hi Petr,
The switch breaks the negative wire that goes to the cell monitors. That shuts them all off.
So if I have a 16s 7p battery, how can I balance charge it using a hobby charger? Or how many cells are needed to be split in this battery pack?
I build large solar battery arrays using wrecked hybrid and I get so much grief for not installing BMS'. Good info man.
Hi Shawn, my shengmilo 1000w 48v ebike blew its BMS and the company sent me another which had also blown (the swine's sent a used BMS with old solder on). My question is can you tell me how to wire the battery to the bike without the bsm please? Its my only mode of transport to and from work. Please help.
Do you have a link to the cell monitor your using? I've been looking (for a lifepo4 version) for a bit, and I haven't found any for a reasonable price. But I also haven't found the one your using. Thanks!
Sure- You can find an assortment of them at HobbyKing: hobbyking.com/en_us/batteries-chargers/battery-accessories/voltage-indicaters.html
Very comical but great info. I know Jehu doesn't use a BMS on his EV van so neat to confirm when you can charge responsibly without a BMS. Thank you kindly for sharing even though it was a couple years ago - just seeing it now :D
Hi . What battery configure do you have supplying your I charger . I just bought 2 1010b chargers 4 30 dollars and maybe 1 12v battery is not enough as is only 70 ah .What do you use in your inbuilt charger pack.I just bought a electric bike adjustment pack and like your reasoning but what is the effect from ripple damage from external ac sources via dc battery to li ion battery's .I see you have mains input by your helical lead to DC charger to another battery then the icharger which supply's the li ion battery's .Do you fully rectify 110v ac straight to the icharger as they must be inbuilt also. Just a question I will experiment myself as that's what it is all about. I know ripple from ac destroys a lot of battery's tho so if you know anything then please let me know.Its probably best too charge an ancillary battery first then disconnect ac and then use icharger as inbuilt system.
Or you can use 110/240 v input to a rectifier unit dubiously connected to the icharger to power the li ion battery's . I trust this is not what you do.
Anyway good channel ,loved your ride through the great Irish /British weather and the road layout all the small lanes omg it's a cyclists worst nightmare other than London.I grew up with peddling on the left side of the double yellow lines right next to the kerb. Yeah anymore and you had 2 be constantly looking over your shoulder for traffic cause they would never even consider giving you any room. Times have changed a lot now but roads still same in GB . Cycle in Germany if you want the best cycling trip of a lifetime in Europe and don't worry most speak English . I know live in Koln and cycling is awesome go to Dorn is most beautiful and naturalistic . Just learn a few German words instead of the normal reply of I only speak English and you will be welcomed even more so. I am a HV engineer living in Cologne and not a tout guide operator but this place is geared for cyclists more than Holland. Anyway enough said. Do you use an intermediate battery pack when charging.I would.Cheers
OK long question MOU! congratulations on your ichargers- that is a good deal!
I power mine three ways. One is with a computer server power supply. The other is with a large 12 volt storage battery. The third is with a lithium ion battery charger of 24 or 36 volts. I have never had any issues with any of those methods. The ichargers are quality units and probably filter out any AC ripple.
My son is remodeling a 250 year old house in Germany. I will travel there soon.
Cheers.
I have also adopted the idea of a open discharge and a small blue tooth BMS to charge and monitor in real time. I agree with all the point made in this video but Am i correct to presume this video was made before bluetooth BMS's were available ? How do you feel about a blutooth BMS for charging/monitoring only now that they exist and are mostly reliable ?
They are better as they allow you to check up on the balance. The real improvement is with BMS's that have Bluetooth and active balancing and allow you to program all parameters, such as this one:
www.aliexpress.com/item/1005004059807727.html?spm=a2g0o.productlist.0.0.23fe582dtbOF3b&algo_pvid=c5fa2f33-93a3-4478-bceb-97ecfe1a9e76&aem_p4p_detail=20220505081953197176857130580017968223&algo_exp_id=c5fa2f33-93a3-4478-bceb-97ecfe1a9e76-2&pdp_ext_f=%7B%22sku_id%22%3A%2212000027934652609%22%7D&pdp_npi=1%40dis%7CUSD%7C%7C166.58%7C%7C%7C%7C%7C%40210318c216517639929768262eb32c%7C12000027934652609%7Csea
Cheers!
i am trying to build my first battery pack, and i am trying to make it capable of 20A for each parallel cell (so 2P = 40A). Only the series conductors need to be high amperage right? I could probably be fine with 7A nickel strips connecting in parallel, since the parallel does not see much current, right?
Hi Shawn Love your sense of sarcasm I have a 54.6v limit charger. Would I be able to limit the voltage down to 53v on a 13series pack to get 4.07v per cell and do I simply connect up the multimeter leads to the charging port of the charger?.
Yes, you should be able to. I use alligator clipped jumper cables to connect the multimeter leads to the charger XLR. The top of the metal charger case lifts off when you remove four screws. Find the tiny blue potentiometer with the gold screw and adjust while watching your multimeter. There is a limit as to how far the voltage can be adjusted, but a volt and a half should be doable.
+Shawn McCarty Thanks for that. After watching your video I will always be thinking BS when hearing you say BMS. Haha. I won't be fitting mine now. I bought a 57v limit charger and literally blue up my battery pack. Took half my
Bike with engulfed in flames. Firemen weren't impressed. Now my wife has a nervous twitch every time I talk about batteries.
Yes, you should be able to. I use alligator clipped jumper cables to connect the multimeter leads to the charger XLR. The top of the metal charger case lifts off when you remove four screws. Find the tiny blue potentiometer with the gold screw and adjust while watching your multimeter. There is a limit as to how far the voltage can be adjusted, but a volt and a half should be doable.
I blew two large cells due to those crappy balance port connectors. This is my main reason for using one module for each cell, you can use better connectors. I think i am going to go this way and build a charger for my new 16Ah 16s lipo project. This way i can break down my packs into any size i want to help fit them around the frame of the bike. Also if i choose to go trials style riding i can make it into an 8s 32Ah or just use half of the battery at 8S for shorter lighter rides.
HI Shawn! wonder if you could tell me, when it comes to lithium batteries i hear so many versions how batteries should be charge, full till light indicated changes, just before it changes. what is in your opinion best to best do for batteries to last longer?
thank you .
Sure. It is well established practice to charge lithium batteries to 4 volts per cell to double the cycle life Most of the charging stress takes places in the last .2 of a volt.
Hey Shawn thanks for all your advice how to set up my electric bike. Just got a new set of Batteries to solve my voltage drop cut off issue. Haven't tested out the new battery but wondered if you could tell me how to adjust the amperage power on my 4 amp 54v charger. I worked out how to reset the potentiometer for the voltage but not the amps.
Cheers
Congrats on your new batteries!
I don't know how to adjust the amperage on your charger. You may not need to. If your batteries are greater than 10 amp hours you should be fine.... If it's critical you could run the charger through a Drok so you can adjust the amps. I've got a video on it..
+Shawn McCarty Hi Shawn I want to expand my battery pack with a 13 x 6 parallel cell pack is it better to do this or attach another 48v pack in parallel?
Thanks
Robert
Hi Robert,
Are you using BatteryBlocs? IF so you can connect your 13 6packs to another 13 6 packs (or any other pack) and make one large 13s12P battery. This means you could use one charger and BMS.
If you have spot welded packs you will need to have two packs that you connect in parallel. There is no other simple choice....
if you wanted a bms on this too, how would a bms work with the split packs? just one 14s is needed and it'll operate when the two packs are connected in series?
Yes, exactly. The two packs are always connected in series, there is just a tap at each 7S to allow a hobby charger to balance.
im not looking at this because i want to build an Ebike like most. But i want to use lithium ion batterys for some tools and a portable radio system. But a lot off people keep yelling you cant just do it because you need a lot of electronics in the battery pack and all that bs. But you just proved to me it can be done with some simple electronics and instead use a better charger(wich is better in my opinion anyway because i would like to see what my batterys did instead of just trusting it will be fine)
Yeah, exactly right.
Hi Shawn. Thanks for the video. Can you point me to where you bought the hobby chargers, battery monitors, and connectors you show in your video? Thanks.
These are just standard parts in the model airplane hobby industry. Try Amazon, BuddyRC, or Hobby King.
Hallo, great video! I want to build a 13s4p battery pack without bms and balance charging and also monitoring it in your way. Where should i connect the fuse you are showing in the video? Is this a special fuse? Is there something else to do for safety?
Thanks.
The fuse goes between the battery and the load. On an ebike that would be the controller. In the event of a short, the fuse will blow. Consider building a 14S battery instead- you can divide it into two 7S batteries and charge it as such.
I will split the 13s4p in 3 parts and charge with a 6s charger. The budjet is tight...The fuse has to be more amps than the controllers?
Yes, the fuse has to have a higher amperage than the controller can draw. On most ebikes a 25 amp fuse is used.