Battery Fire thread - stay away from LiPo Battery Packs

[BahamasBiker]

OSET electric trials bike fire, nearly burned down his garage:
http://www.trialscentral.com/forums/topic/57187-oset-lipo-fire-scary-near-miss/


SNIP:

Oset Lipo Fire - Scary Near Miss
Started by scottwitting, Sep 29 2015 12:06 PM

Posted 29 September 2015 - 12:06 PM

I thought I'd share a recent near miss I had with some lipo batteries whilst attempting to convert our little lads 12.5 from lead to lipo.......

After running a 36v (pairs of 5s batteries in series) 16" bike on lipo for a while with no problems I decided to get some for the young un's 12.5. Went for some of these http://www.hobbyking..._Lipo_Pack.html

which, after careful measuring, seemed like they would fit nicely. Once they arrived I taped them together, wrapped them in some 8mm foam and duct taped them up. Trying them in the bikes battery tray they were a good fit, just dropping in under their own weight. I put them on charge whilst I got to work soldiering up a harness. One charged fine but the other never seemed to want to finish, one cell would not go above 4.18v. In the end I stopped the charge myself. Next I attached the parallel lead and went to fit them in the bike again. This time they were a tighter fit, as if the batteries (or one) had swollen a bit. I was just easing them in when there was quite a loud and#39;pop' and smoke started to be emitted. My first reaction was to step away but then I realized what might be happening so grabbed the bike, wheeled it outside and ripped out the batteries. Within less than 30 seconds there were three foot high flames coming from the packs, which after several more minutes burnt out leaving a smoldering pile of ash, see pic below.

I'm still not certain what caused this, the batteries weren't punctured or impacted in any way. The force I was applying to the batteries at the time was probably similar to a small child standing on them, not excessive in my view. I'm quite certain the battery that and#39;popped' was the one that failed to charge properly. I'm progressing this with Hobby King to see what they say and hopefully get a refund.

Looking back I feel extremely lucky not to have destroyed the bike or the entire garage. The foam base in the battery tray melted and there was a bit of smoke dust on bits of the bike, but no real damage.

I'm going to be much more careful in future how I store and charge these batteries! They are great when working ok, but can obviously go badly wrong!

 

[EVTodd]

OSET electric trials bike fire, nearly burned down his garage:
http://www.trialscentral.com/forums/topic/57187-oset-lipo-fire-scary-near-miss/


SNIP:

Oset Lipo Fire - Scary Near Miss
Started by scottwitting, Sep 29 2015 12:06 PM

Posted 29 September 2015 - 12:06 PM

I thought I'd share a recent near miss I had with some lipo batteries whilst attempting to convert our little lads 12.5 from lead to lipo.......

After running a 36v (pairs of 5s batteries in series) 16" bike on lipo for a while with no problems I decided to get some for the young un's 12.5. Went for some of these http://www.hobbyking..._Lipo_Pack.html

which, after careful measuring, seemed like they would fit nicely. Once they arrived I taped them together, wrapped them in some 8mm foam and duct taped them up. Trying them in the bikes battery tray they were a good fit, just dropping in under their own weight. I put them on charge whilst I got to work soldiering up a harness. One charged fine but the other never seemed to want to finish, one cell would not go above 4.18v. In the end I stopped the charge myself. Next I attached the parallel lead and went to fit them in the bike again. This time they were a tighter fit, as if the batteries (or one) had swollen a bit. I was just easing them in when there was quite a loud and#39;pop' and smoke started to be emitted. My first reaction was to step away but then I realized what might be happening so grabbed the bike, wheeled it outside and ripped out the batteries. Within less than 30 seconds there were three foot high flames coming from the packs, which after several more minutes burnt out leaving a smoldering pile of ash, see pic below.

I'm still not certain what caused this, the batteries weren't punctured or impacted in any way. The force I was applying to the batteries at the time was probably similar to a small child standing on them, not excessive in my view. I'm quite certain the battery that and#39;popped' was the one that failed to charge properly. I'm progressing this with Hobby King to see what they say and hopefully get a refund.

Looking back I feel extremely lucky not to have destroyed the bike or the entire garage. The foam base in the battery tray melted and there was a bit of smoke dust on bits of the bike, but no real damage.

I'm going to be much more careful in future how I store and charge these batteries! They are great when working ok, but can obviously go badly wrong!

I'm calling bull on this one. Kind of odd that it happened right as he was "easing them in" with the force of "a small child standing on them" . Sounds like something was shorted or he punctured a cell.

EDIT - I just read the thread from that site. You failed to put his response to what may have happened:

"I think I squashed the batteries on the side so that may have been it."

This wasn't a lipo that caught on fire for no reason.

 

[Hillhater]

Yep !
You don't manhandle lipo and squash it into places and expect no issues.
I wouldn't waste the time on trying a HK claim.

 

[amberwolf]

One charged fine but the other never seemed to want to finish, one cell would not go above 4.18v.
<snip>

I'm quite certain the battery that and#39;popped' was the one that failed to charge properly.

Seems like a possibile cause right there. If a cell had internal problems, of whatever kind, and then was physically stressed, perhaps it failed from that?

Or...something in the wiring (balance wires, etc) was shorted by the physical manipulations and stresses....

 

[999zip999]

It's hard to realize all the potential power stored in this beautifully packed little 6s battery packs with that fat red and black wires coming out of them. This includes all ebike batteries. s
Stored energy

 

[Ykick]

Weird charge and/or discharge behavior is always a serious CLUE to step back and perform qualifying tests. If you’re unable or unwilling to perform RC Lipo stress testing you shouldn’t be messing with anything except safer chemical compositions.

And another thing, any force is too much force when applied to pouch cells. Granted, evenly applied compression is one thing but shoving them into tight spaces is another.

A nose can be valuable detector of impending problems. Any hint of “sickly sweet cherry” solvent odor is enough to investigate further.

Good lesson for you with minimal damages.

 

[dogman dan]

Failure to test for quality before use as a full size pack. Bad cell puffed, and was ready to blow when he shoved on it.

Stored where you would not build a fire, if he was planning to leave it on the bike.