Example of Ebike Battery Disassembly and Diagnosis
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- Опубликовано: 8 сен 2019
- In this video, Peter opens up a downtube battery pack that is unresponsive to try and identify the cause and find out of it is repairable.
In general, if there is no voltage on the output port of a battery pack, it means that either
1) The Battery Management System (BMS) circuitry has tripped for some reason
2) There is a break in the tab welds joining the cell groups together
3) There is a failure in the on/off switch wiring or fuse
4) The cells are fully discharged to an irrecoverable state (less than 1.5 V/cell)
Items 1-3 are usually repairable, but the only way to know for sure if a battery can be repaired is to open up the battery pack and measure individual cell voltages across the BMS header, which is what Peter demonstrates in this video. If all the cell groups are balanced and over 3V each, then the issue is typically from a BMS circuit that has tripped for irrational reasons and replacing the BMS (or sometimes just unplugging and reconnecting it) will restore to an operating state.
If you have one or more cell groups that is noticeably lower than all the other cell groups, then there is either a BMS circuit that is draining that cell (such as a blown bleed resistor mosfet), or there is a soft short circuit in one of the cells (rare with quality 18650's), or you have a broken tab weld on one of the parallel batteries causing the group to have lower capacity than the rest.
If you have a case where the cells are all between 2V - 3V, then typically that means that the battery has been in stored in a flat state and the quiescent current draw of the BMS circuit has drained the cells below the shutdown cutoff voltage of the BMS. In this case, you can usually trickle charge the pack at a low rate (say a few hundred mA) bypassing the BMS until all the cells are over 3V each, and then after that you can reconnect the BMS and charge it normally through the battery's charge port.
If you have any cell group that is less than 1.5V, then the only way to properly repair the battery is by replacing the cells, at which point it is almost always cheaper and much faster to just buy a new pack. Do not try to recover lithium cells that have been drained below to low voltages like this, it very often results in a massive inferno. 
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The Jim Carrey of battery repair!
Tip: if it had an USB port then most likely the 5V converter is what has caused the drain. Cells can last 2-3 years without voltage loss and BMS is seldom hungry enough to kill a battery in 6 months.
that's what i was about to comment 👻
Exactly!
....You mean it's the BMS that kill the battery when they are discharged ??
Lustigt tänkte samma :)
How does the BMS kill the battery ?
Very great Video! very informative for many peoples that have broken battery!. One VERY IMPORTANT thing to also mention is that many chinese chargers wont take care of trickle current when connected to overdischarged battery and this might create alot of dangerous heat on the cells as their RI is higher than normal at this point. Many BMS wont have the UNDERCHARGING VOLTAGE protection feature which permanently disable charging to a overdischarged battery. Also overdischarged battery in very low range like below 2V, will suffer from copper migration from anode to cathode and will also have dendrite that grow perpendiculary from the electrode surface inside and over the time they become conductive!!.. these can eventually puncture the internal separator of the cell and make a direct short circuit! between anode and cathode... without any warn!... That is a serious information to know for people that want to use/recover overdischarged battery !
Very interesting, thanks for these, I appreciate all the helpful resources you provide online
Alright Jim Carrey good work. Show us bit of a surgery of that battery.😂🤣
But it's dead, 0.26v/cell, what would be the point?
I see Hollywood in your future, Pete. Way to go! - Mike
Many thanks for the video. How should one store batteries if not being used for few months. I read they should never be at full charge or extremely low charge. Batteries should be at about 40% and charged for about 30 minutes every month. Is this correct?
I have just bought a spare battery from some who bought it new but never used it and this has been sat in his garage for six months. What is the best wsy to test it is working as it should? When battery is out of bike and power button is pressed for 5 seconds and released all five bars light up, indicating it is operating at 100%. It is the battery for Carrera crossfire. Thanks
Yeah! More of these please! You folks are amazing in all aspects!
And thank you for all your help and insight
Can't you magnetically charge each cell in parallel with a healthy cell to give it enough voltage to then allow it to be thrown on a cell charger?
Hi there how u doing is it worthied fixing my battery if there is some corrosion on the circuit board
I have a question. I checked voltage in each battery cell on a 36v 500w e-bike battery, they were 4.3v in each cell, accepted 5 cells. Cells say they are 3.6v, 2500 mAh, 9.0Watts. 5 batteries read 1.2 volts when still in the pack. I figured they were bad, so I removed them. Then I checked them again out of the pack and got crazy numbers. Here are the numbers, Why? 5.6v, 1.9v 5.6v 1.3v 13.1v HELP PLEASE!
Hello sir, could we please converse with you about a battery exactly the same as the one you stripped down that isn’t charging. Do they have internal fuses?
Thanks for taking the time to read this.
Luke.
Can you please get a closer look at the BMS ?
Good video. Was just waiting for the explanation of why charging batteries that discharged is so bad.
Each of my cell packs had 3.6 volts per voltmeter readout but battery still wouldn't run ebike. Could it be bad bms? Can those be purchased and replaced?
i have the same issue, my battery wasn't charged for over 10 months. I charged it and it holds voltage for days but it still shows low battery on display..
I liked it. Thanks.
Trickle charge the each cell with fully charge 18650 positive to positive and negative to negative for 40 sec soon they charge goes up to over 1v or 1.40 v then u bring them back to life then fully charge them I done it many times and it works...
95%
nope, very bad practice. below 1v is just accident waiting to happen if you recover them
@@ademiravdichow
I have a triangle battery of 48v and 28.8 ah, I have been using it for 17 days, but yesterday it did not turn on, when I put it on the charger the panel turns on and says 100% charged, without the charger the panel does not turn on, the battery does not pass energy to the electric bike, can you tell me what the problem is?
Well your BMS circuit is tripped and only passes through the charger voltage when the charger is connected. Your starting point should be contacting the vendor who sold you the battery, as this is their responsibility to support you.
Hi, i have a lithium battery problem in which my ebike dies whenever i throttle for too long or too much, then i have to reset my breaker to bring the power on again, can you tell me what the problem is? I hope you can help, thanks
The breaker is getting to warm. Its probably that cheap braker from AC voltage for house installation. That shit has nothing lost inside an ebike. Change to an correct DC Fuse.
Never thought I would learn so much from Jim Carrey himself. Bro got bored and decided to study electric stuff
They wear still possibly fixable if the cells dis not have protection on each sell then you could force charge them
So if i were to go travel for a long time, would the best idea be to actually disconnect the batteries from the bms to prevent this?
Nah, just store your battery charged at 80%.
BMS consumption is around tens of uA.
You can last, theotrically, years before the BMS drains it.
What must have happened, is that the battery had been put to storage while already drained, then the bms drained what's left.
@@xmtxx Ah yeah makes sense. Cheers :)
Jim my friend accidentally put the key in the battery charger slot and shorted it out it smoke !!!! Is it still fixable?
Almost always yes, but it may require a replacement BMS and replacing that is often a non-trivial thing. Ideally the charging port would be fused in a way that can handle external shorts without any circuit damage, but this is not always the case.
I have a similar battery with on/off switch that won't switch off what do you think the problem is
We've seen BMS failures that cause the battery to stay on and we have also seen fault on/off switches. The latter is easier to fix of course.
My battery showed 84% life today before it shut down. I may have asked too much of it while trying to plow through some deep snow.
Input (where it's charged) shows 29v and output (where it connects to the bike) is giving 3v.
Is there a way to reset the BMS?
Turn Life 48v/14AH 672WH
BMS reset via charging through output connection worked!
Indeed that will typically do the trick if disconnecting and reconnecting it from the controller doesn't.
2:15 is just comedy gold.
excellent..!
Following !
I have a battery that “dies” when installed onto my ebike when torque is applied. The power indicator green lights go dark . When I test the voltage , it is between 5 and 6 volts. When I plug this battery into the charger for 1 second , the green lights turn on indicating full power , the voltage is now 51ish volts.
What is causing the circuits to trip?
Typically the bms circuit is tripped for one reason or another,like a single cell group at our near LVC
@@GrinTechnologies , so not repairable and I have to spend $900 for a new battery?
Battery bms can’t supply amps required. You can replace BMS or bypass discharge through bms going straight to battery. My bike pulls 40 amps, bms only supplies 20amps so full throttle it cuts out.
I thought you could bring them back as long as their was voltage. I brought some large format 64ah cells back from 1.2v and I only saw a small decrease in overall capacity(3 or 4ah). I haven't seen any internal discharge. I left them at 2.8 for a month to see if there was any decrease in voltage( no change over the month).
It's hard to give definitive advice here and I think a lot of the potential damage depends on the duration of time that the cell is at the very low voltage. We have absolutely seen cases of cells that were below 1V that were recovered which burst into flames on recharge, or which on recharging ended up have high self discharge and would always go out of balance. We've never seen that happen with cells that were above 2.0V when recovered, and that's why we say in between 1-2V is something of a user-beware grey zone. You also don't know on this recovered cell what the long term cycle life ramifications would be or if you are greatly increasing the odds of a catastrophic failure down the road, so I'd recommend keeping a close eye on it.
Thank you for video, better microphone is highly revomended!
You know a lot about ebike batteries! I have a question for you please, I have an ebike battery (48V lithium ion battery 14 ah) that has a small crack in two areas around where it plugs into the bike (the plastic battery dock/mount). The bike seems to be working fine. Is this battery dangerous? It seems to be working fine (I've ridden it for 2 weeks no issues). The bike company wants me to replace it, but maybe they're being overcautious. I'm thinking of putting super glue in the crack (which should seal it from water etc). Please let me know what you think??
It's unlikely that the crack is a safety/danger concern, but if the bike company is offering to replace it for you, then I'd certainly take them up on that offer to have a non-cracked case. What's the downside?
glue works to seal many different things, i use it all the time to seal damaged things and also to stick things together, anytime you get a crack in something that water or dirt can get in, fix it by glueing it, i use guerilla glue and other ones to fix many things
What is the make of the charger you showed. It sounded like psycho-tashi.
Qwe-esss-scent. Is how you pronounce it. Good video!
kwee-ESS-ent ruclips.net/video/CDivrV-9vWg/видео.html
This guy is worth about 50 Jim Carreys.
😂 Our ebike battery measured across pin outputs show only .996v instead of 52v, we just ran about 5miles and back home, next day nothing on display. what is the issue? Thanks
Check the voltage on the charging port pins to see what they show there. Obviously now the BMS circuit on your pack is tripped so you are not getting any voltage on the output port.
@@GrinTechnologies we found out it was cheap,plastic switch they put on😇
are you based in nyc i need help
I don't get it because my battery was running then dead and wouldn't charg then I tested it and its like this
cells are battling each others the most, when fully charged on storage. so charging around 50% when stored, might be a better solution.
for long term storage, fully charging is not bad
A paper weight.... A potentially very dangerous paper weight 💥
Why does my 36v battery charge to about 40.5 volts but then cut out while riding it at only about 39.5 volts?
You'd have to open it up to find out! If you have a very badly unbalanced cell group, with one cell that is at like 3.0V while the rest are at 3.9V, you would have this kind of behavior.
@@GrinTechnologies OK thanks for your advice.I am reluctant to get involved in all that stuff for now.
My bike appears to be a NAKTO Ranger though it was sold in the UK under another colour scheme with no name on it except the logo 'Smart' & I cannot find a way to buy another battery. So I have bought a Yose Power one that I've bolted on over the top & that seems supa dupa It is just that I would like to use the original one in situ then I could double the range.Problems problems......
@@GrinTechnologies PS: Is'nt the BMS supposed to prevent situations like that from occurring?
@@nicholasmorrill4711 it cant if the specific battery has gone bad and doesnt retain voltage very well
@@ademiravdic Well I don't understand why if a specific cell has gone bad why it dos'nt just cut it out & leave you with a slightly reduced overall capacity.
Good what not to do video but I admit I was hoping it was saveable in my head I heard muah muah muah when I saw the battery voltage 😢
I'm wondering if you may know the answer to this question?... I have this exact battery and for some reason it makes a crackling noise when I switch the speed controller on? Any ideas?
Thanks
Paul.
The outer cover used is generic, many battery builders use that style. Unlikely to be the same as yours
That's cool, the guy looks like and got the same expressions as Jim Carrey!
All righty then.
i have heard of people being able to recover 0 volt cells and getting back to working though it is risky and should be done carefully.
I have directly witnessed batteries go up into billowing clouds of smoke and flames, warehouses burning down, living rooms getting charred, and more from people charging up batteries that had been down to near 0V. Carefully doesn't begin describe the risks involved.
@@GrinTechnologies probably shoddy batteries from china or you did not carefully charge them they have to be charged up slowly in bursts and monitor temperature to make sure they dont get too hot i have recovered batteries ok safely
Any idea how to do it safelly ?
I don't really want to open a battery to see the cells, i'm not equiped to put it together again...
I do have access to a charger with variable voltage(V) and intensity(A) but i'm not sure that, even if i bring the V down i can charge it up again through the bms
Buy the self build E battery kit.$45 easier to replace a cell.and rebuild able.
I think Jim Carey is your brother. Your the next future episode in Hollywood 😂😂
200mA and perhaps the voltage will lift to normal state.
Sometimes yes, but it can be a dangerous to recover cells that are a very low voltages regardless of how small of a current you use.
can i ship you my battery for repair
You're actually not technically allowed to ship any lithium battery unless you are a certified class9 dangerous goods shipping agent. The logistics of battery repair is quite complicated.
@@GrinTechnologies I am 67 year old Elevator techincian seen more safety training than 95 percent of people ever employed! can you help me or am i just to repair my own
Jim Carrey electronic man
My thoughts exactly.
It's 'quiescent ', not 'quescient'.
This guy reminds me of Jim Carey the batter tender! Or the cable buy! LMFAO!!! You forgot to mention parasitic discharge due to a faulty USB port!!!!!!!!!! REEEEPORT!!!!!
Urgent! Need instructions on disassembly of one sleeve bike battery. Case is all aluminium. About 390 x 110 mm
Thanks. Get an ebay mic please/cheap.
Or improve the acoustics of the room!
What a bad bms . That’s way I build my batteries my self . Imagine buy a good battery with Panasonic cells and a 5 dollar bms ruining the pack . This is not acceptable. I failed finding a good bms to buy for my ebike and I come with idea to use a Hilti 36v battery bms . Gues what? Works flawlessly.
There are good BMS circuits out there, but they are hard to source by themselves. Usually the BMS companies only sell in volume to battery assembly houses and not retail.
Grin Technologies , where is your work shop located I have a battery that might need a new Bms!
Hi Jim can you do my bms, READS 52.V .BUT LIGHS DONT STAY ON UNLESS IS PLUG TO THE CHARGER .ITS A HIALONG 3.NO WAY TO RESET.
It a 48 v 13 ah.It was short circuit accident.
@Bob J there is no fuse i looked everywhere. No fuse at all.thanks
No fuse
Is there a address we're i can sent my baterry to be repair.
"quiescent" draw, but you said: "quescient" which is not a word. Maybe you were getting it mixed up with the word "prescient"? Anyway, thanks for the helpful video.
ALRIGHTY THEN Wtf Is Jim Carey doing repairing batteries
Aarrrlll'righty'then,,
This is why some of us don't like using a BMS in our batteries and would rather manage them ourselves. The average consumer want's plug and play and that is understandable but it can cause early battery demise.
I didn't know it was the BMS that would destroy low voltage battery !
That's so damn dumb ! It just mean you HAVE to recharge your battery often, can't even go to a road trip for some month and come back, you will have a dead bike/scooter...
How does someone use a battery without BMS tho' ? Genuinely intrested
@@Samishii00 Install a balance connector and plug it into a voltage display with an audible alarm. If any cell gets below a certain voltage it's time to stop pulling power from it. Charging needs to be done using an intelligent balance charger instead of a dumb brick.
or just dont store your bike for months with 5% battery lol
Audio not good
Jim Carrey???
Jajajajaj 👍
E-bike batteries are junk if they can become useless after leaving them sit for a few months. Shouldn’t be legal to sell crap like this. I don’t have this problem with the lithium batteries that I use with my power tools.
The power tool batteries are even worse in that they don't even have a BMS circuit for the most part, so they go totally irrecoverably flat in a matter of days if left connected to an ebike motor controllers. Try it and you will see how junky designed powertool batteries are in a battery to battery comparison. At least an ebike battery with a BMS circuit will trip at ~2.7 V/cell and then gives many month of margin before self discharge brings it too low.
The difference is that cordless power tools are intrinsically off with zero quiescent current draw, while most ebikes have an on/off switch that the user can inadventertly leave on and allow the battery to be drained over time even when they aren't using the bike.
@@GrinTechnologies My e-bike battery was completely removed from my bike over the winter and is now useless without taking it apart and "jumping" it. My power tool batteries never do that. I'm guessing it must be the BMS board putting a parasitic drain on the battery, or the batteries themselves are just trash. Regardless, e-bike batteries need to be improved. I shouldn't have to risk catching on fire and inhaling toxic lithium fumes because the $600 battery I bought discharges to 0V over a 3 month period.
OK, that then is a poorly designed battery BMS board. There really is a large range of quiscent drains, really bad ones are over 1mA which translates into about 1Ah every 5 weeks, while most are about 150-300 uA which will drain 1Ah in more like 4-6 months. If you store your battery with 2-3Ah left in the tank it will last a year no problem, but if you remove it with only like 1Ah left then yeah it can be at a real risk. We fully agree that the quiescent current drain of the BMS board isn't nearly emphasized enough, in fact I don't think we've ever seen a single battery spec sheet that mentions this value.
On our LiGo BMS, we were able to have the batteries go into a sleep mode where the drain is just 2uA, but there was a bug in the firmware meaning some devices never went into deep sleep mode automatically and so suffered the 200+ uA drain.
Get yourself a lavalier microphone so that we are not listening to a terrible recording of a voice that is otherwise doing everything possible to convey important information well.
triple charge ?
*trickle charge. Using very low current to return the soc (state of charge) of the cell to a minimum voltage