LiFePO4 batteries explosion risk mitigation

gte718p said:

...How many Mac Books or Dells have you seen spontaniously combust?...

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Well, back in 2000, I got a whole lot of replacement batteries from Dell due to a fire risk recall. Those were NiMH. But you make a good point. The reputable companies that put batteries in their equipment tend to use stuff that's pretty safe. The problem is that the market is awash in fly by night brands that are gone before a recall can happen, and they'll stuff whatever they can find from the lowest bidder in your Amazon package.

rlitman said:

You had me up until that insanity. If that argument fails for propane or natural gas, then it fails for emissions of ANY flammable gas. And a venting cell releases just as much gas as the A2L refrigerants on the market that require flammable gas sensors that are such a big debate today.

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I'm not suggesting that you should stick around a lithium battery that's undergoing thermal runaway. Whether it's emitting flames or not, a cell under thermal runaway is dangerous and you shouldn't be anywhere near it without significant PPE including SCBAs.

I am simply stating that LFP cells under thermal runaway do not reach the auto-ignition temperatures of the gasses they emit. Thus external ignition sources are required and you don't always have an external ignition source.

rlitman said:

I think here we also need to differentiate between CELL thermal runaway and PACK thermal runaway. Everyone who says that thermal runaway isn't risky has only experienced the first. Anyone who's experienced the second knows your best option is to run away.

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Thermal runaway is a cell-level phenomenon. While it can propagate from cell-to-cell through the pack, it just becomes a multi-cell thermal runaway. Safety standards like UL 2580 do not call out "pack thermal runaway" for a reason, rather they describe cell thermal runaway and propagation to adjacent cells.

Whether it's a single cell thermal runaway or a multi-cell thermal runaway, I wouldn't recommend living beings remain near it without significant PPE.

I never said that thermal runaway isn't risky. There are many risks, fire is only one possible risk.

rlitman said:

I thought all plug-in EV packs were liquid cooled nowadays.

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Nissan leafs used air cooled batteries until the 3rd generation was released this year. That's the only mass production EV that I'm aware of using air cooled propulsion batteries.

JCrabtree4 said:

...Thus external ignition sources are required and you don't always have an external ignition source.

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We'll never see eye to eye on this one. Can you imagine a propane installer making this excuse? Here's an insurance perspective on it: