Can I get lifepo4 to catch fire electrically?

Joined
Apr 25, 2014
Messages
2,782
Location
Sausalito
I made these batteries with A123 cells without a bms thinking they were a safe chemistry and no rush and I’d drill through the resin later and balance through there. Months after making and riding a lot I drill through and can not get a solid voltage and it fluctuates. A big disappointment and will have to make the batteries again. Also I’ve had a gas release one time on each battery as well: a bubble formed in the resin. It’s a relatively soft resin. I lanced it and it smelled that sweet smell. I should’ve checked every cell beforehand and I’ve found another of these many loose used A123s I got that’s dead(won’t go past like 1 volt even at 5.5 amps charge and drops back to 0 quickly when off the charge.). So I keep cycling through these messed up built batteries anyway and I watch them while charging and check for heat but don’t feel any (although hard to tell through the resin.). I’ll have to do a full discharge and charge again and see how much energy shows within the voltage range but that’s the only indicator I can think of to know what’s going on.


I initially got a precision resistance meter to check cells but it was so finicky I gave up snd returned it. So now I’ll just do a full charge and discharge of one cell from each pack of 48 used cells and that’s my only testing right now. I’m thinking of building a 3 wire precision resistance meter using the three wire method with a repeatable consistent contact, like a standard sled, then test each cell quickly at the same voltage. That seems my best bet. (Or could get the accurate resistance meter again hook it to a sled.)


What you think of my problems and possible solution?


Ive never read about lifepo4 going into flames purely electrically and testing I can’t get one of these cells to go to flames electrically but then again I don’t know what’s going on inside the packs and my tests don’t include 50v being run through a mystery cell. (I just shorted a bunch and run maybe 12v through a shorted cell)

Making me question welding .1mm copper and potting cells..and my new frame is almost done and had the same plan
 

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