Electric Bike Battery Problems

[FinlayT]

Video of E-Bike Battery Smoke

Help! There was smoke coming out of my e-bike battery earlier. It stopped when I inserted the charger. What can I do?

 

[soundwave]

throw it out the window asap DO NOT CHARGE IT! AS COULD EXPLODE!

 

[FinlayT]

throw it out the window asap DO NOT CHARGE IT! AS COULD EXPLODE!

Unfortunately that is not an option. Not only am I unable to afford a new bike battery, but also I have just finished recharging the bike and it seems ok.

 

[soundwave]

that batt is dead the smoke is from the cells if it goes in to thermal runaway it will explode and burn your house down.

do not charge it or use it on the bike as it is now a bomb

 

[FinlayT]

that batt is dead the smoke is from the cells if it goes in to thermal runaway it will explode and burn your house down.

do not charge it or use it on the bike as it is now a bomb

Thanks for your very helpful contribution. I’ll take my chances though. The battery still works and it charges up ok.

 

[soundwave]

using a batt that is smoking is utter madness but it is up to you but you need to open it up and find where it is coming from as all it takes is for 1 cell to go bad and take out the hole pack in the process.

that smoke is not melting plastic and looks like a cell is venting electrolyte which means a short somewhere or a cell has gone bad.

some cheap batts use very basic bms so wont be able to tell if a cell has gone bad and when a big load is put on it like a bike motor it can go kaboom.

 

[FinlayT]

using a batt that is smoking is utter madness but it is up to you but you need to open it up and find where it is coming from as all it takes is for 1 cell to go bad and take out the hole pack in the process.

that smoke is not melting plastic and looks like a cell is venting electrolyte which means a short somewhere or a cell has gone bad.

some cheap batts use very basic bms so wont be able to tell if a cell has gone bad and when a big load is put on it like a bike motor it can go kaboom.

I was unaware of Lithium e-bike Battery fires and I have since moved my ebike battery from my house into the shed. Thanks so much for alerting me to this.

 

[soundwave]

 

[Nealh]

lion batteries don't smoke for no reason, even if it charges it needs investigating at the very least to know why.
Hellfire just watched your film, something has shorted out in the battery case. It might be a wire melting or a pair shorting, it seriously needs investigating.

 

[FinlayT]

lion batteries don't smoke for no reason, even if it charges it needs investigating at the very least to know why.
Hellfire just watched your film, something has shorted out in the battery case. It might be a wire melting or a pair shorting, it seriously needs investigating.

Thanks for your reply. Do you think there is serious risk of it catching fire? The last guy who responded got me seriously worried about that.

 

[cyclebuddy]

Nobody here is being melodramatic. When a lithium battery starts to vent like that, it indicates a serious fault and you have no idea of what could happen next: It could easily have exploded in your face. Soundwaves initial reaction of getting the battery outside into open space is the sensible reaction.

 

[Benjahmin]

Seriously? Any smoke from any electrical device is bad news.
Also is that sizzling sound on the video coming from the battery too?
Get it out of the house and, if you want to keep your shed, out of that too.

A battery is not like a mains problem where you can turn off the voltage and then investigate. There are no breakers here. There is no main switch. You are always working live. It may 'only' be 36v but, under short circuit conditions, can produce a lot of heat making current. As I understand it, once a lithium ion battery goes into thermal runaway it produces it's own oxygen

 

[egroover]

Dude, do not hesitate to dispose of that battery, get it outside and then taken to tip to be recycled etc. Risk to life and property is not worth the cost of a new battery (£160)

Pardon our interruption...

 

[Nealh]

Thanks for your reply. Do you think there is serious risk of it catching fire? The last guy who responded got me seriously worried about that.

There is a possibility, to a point batteries are stable until something goes wrong.
I doubt a cell has vented as it doesn't release smoke but electrolytes and give off a strange smell, however smoke is released when something burns so my feeling is that the smoke is electrical either wiring or a pcb component.

I wouldn't want to be riding/using the battery or trying to charge it, without a proper internal diagnosis.

 

[Nealh]

If the battery is under two years old then it will be in warranty, Halfrauds need to replace and recycle it. Don't take the battery in to them but first talk to them and show them the clip to decide the next step. Don't be fobbed off by them as it has a two year warranty.

 

[FinlayT]

If the battery is under two years old then it will be in warranty, Halfrauds need to replace and recycle it. Don't take the battery in to them but first talk to them and show them the clip to decide the next step. Don't be fobbed off by them as it has a two year warranty.

I have had the bike since January 2020 so the battery is out of warranty and the problems I have had with the bike battery are my fault because I fell into the canal when I was cycling a week ago. I doubt there is anything they could do aside from supplying me with a new battery, which I would have to pay for and would be very expensive (£265 as quoted online). I didn’t realise however you can buy essentially the same battery but much cheaper from eBay so thanks to the person that pointed that out.

 

[FinlayT]

Seriously? Any smoke from any electrical device is bad news.
Also is that sizzling sound on the video coming from the battery too?
Get it out of the house and, if you want to keep your shed, out of that too.

A battery is not like a mains problem where you can turn off the voltage and then investigate. There are no breakers here. There is no main switch. You are always working live. It may 'only' be 36v but, under short circuit conditions, can produce a lot of heat making current. As I understand it, once a lithium ion battery goes into thermal runaway it produces it's own oxygen

The sizzling sound on the video was coming from the battery. I noticed the smoke when I came back from my cycle ride on Sunday, I then fully charged up the battery which took a few hours and after about 5 hours it was still making noises so I took the battery out the house and put it in the shed. I am no scientist and I have no idea what thermal runaway is. Please would someone explain in simple terms what it means. Thanks.

 

[sjpt]

If a fault means the battery is generating heat quicker than it can disperse it. That will cause it to heat up, which may make the fault worse so it generates even more heat, and heats up quicker still. An so on ... runaway.

The burning in the battery isn't 'normal' burning; most regular ways of putting out a fire won't help.

Imagine the energy from running a 1 bar electric fire for 1/2 hour, all trapped in the battery and trying to get out.

 

[Nealh]

Did the bike also end up in the canal ?

 

[FinlayT]

Did the bike also end up in the canal ?

Yep! I managed to get it out fairly quickly though. I have come to the conclusion that I simply cannot use my bike battery any longer however. I went out on a 20km cycle on Monday and the bike battery started producing smoke again when I turned it on. It needs replacing. The only issue I have is the cost. Halfords are quoting £265 for a new battery, which is a lot when the bike was only £479 to begin with, and the other battery someone suggested on this thread that you could get from eBay for £160 is 36V when my current battery is only 24V and I don’t know if that would work properly. I am at the point of considering whether I should just buy a new bike. I have had that much work done to my bike over the 2 years/5,500 miles I’ve had it for, including 5 punctures on the back wheel, 2 on the front wheel, both tyres replaced and both sets of brakes replaced. The thought of spending any more money on the bike I really struggle to justify.