How to put out / extinguish a lithium battery fire?

Just let it burn… Bring marshmallows not fire extinguishersimage

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you legit need a class D copper powder fire extinguisher… ABC (traditional red extinguishers) will not work because as someone stated earlier, the li-ion cells produce their own oxidizers as they burn. Class D copper powder extinguishers are USUALLY not available in smaller than 30lb containers tho, so good luck carrying that around everywhere… i have one in my workshop and it cost me 800 USD from a local supplier who also recharges them every 6 years for free if the seal is not broken

This is not true, you only need a class D for Lithium Metal since it has Lithium in solid state and alot more than in Li-ion. One of the best ways to put a li-ion fire out is by reducing the heat. One of the go to ways in the industry and research is to use water, you can pour that directly on a li-ion fire and around it to stop it from spreading. Pouring water on a li metal fire would only make it worse. Foam works best but CO2 and ABC still works on normal lithium fires.

thanks karma

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Hey! I wanna help ease some worries…How long have you been charging at home? Keep in mind that we see a disproportional amount of bad cases because everybody else without problems isnt posting about it. If we posted every single day about how we DIDNT have a fire, this forum would be OUT OF CONTROL. Just dont cheap out with your components and make sure to protect them as much as you can. Having a nice BMS/high quality tested cells mean nothing if they’re flopping/rattling around in your enclosure while you ride.

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There is that one in a million chance that you got a factory bad cell that fails. But even then if you are worried about your batteries catching fire you probably shouldn’t be building them.

Monitoring the health and state of your cells is like #1 in my mind for safety, which makes it crazy to me how many people use “dumb” BMS’s that don’t tell you anything.

Have shared this a few times

I shamefully only have a regular fire extinguisher at my place, I’ll have to make a trip to the local homeless despot to get some sand but I think it’s the best option. My battery enclosure allows me to slide out the batteries for charging but I doubt I could get then out in case of a :fire:. A small pouch of sand and I could probably at least direct the fire away from the rest of the electronics.

Only opportunity I see for my cells to catch fire while on the road are something shaking loose and wires shorting in the battery box.

This is perfect, dankeschön :slight_smile: I just ordered two of them and am already feeling better :smile: I’m thinking of putting this stuff in my case between the 3P-Packs so in case of a fire the stuff does its magic before the deck catches fire… mhhhh lets hope its not too heavy edit: Its 250kg per sqm (max), which would be ok. In my case this would be 250gr addictional weight which is compared to the heavy stuff nothing :slight_smile:

I carry that Tundra can of extinguisher in my backpack. I have no idea if it would put out a battery fire. Realistically, I carry it becuase I plan to use it to prevent a fire from spreading if I’m next to dry brush.

@Deckoz do you actually check individual cells often! That seems a bit extreme for most of us. Have you looked into that BMS that uses an app which show voltage per cell (group?)

Welcome! I think on Amazon it’s written something like 1,4kg for the 4l pack (with the box😉)

More details: https://www.extover.com/en/characteristics/data-sheet/

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My new charger shows IR per cell and across the whole pack… So I see it whenever I’m charging, I’m still getting used to interpreting the numbers with seeing different values from different batteries but still pretty limited experience or knowledge. If I went with a BMS would definitely want the kind that can report via a phone app.

Running two balance plugs, to check the parallel groups ie “cell one” aka a parallel group isn’t that hard. Especially when you are just “Learning” how lithium behaves and degrades over time.

  • do I really check them every charge? No because I’ve been working with lithium ling enough to know what to expect
  • when do I check the individual groups then? As I mentioned in my last post, understanding lithium, and monitoring your whole pack IR can give you a tell tale clue that a single parallel group is off. Once your whole pack IR goes off, finding the parallel group with an IR that doesn’t match the rest is easy.
  • but IR isn’t voltage so how do you know it’s balanced? Simple one of two things will happen, the IR will change, or the battery no longer reaches proper charge voltage. Normally both happen together. At which point back to bullet two. So you measuring IR and pack voltage at every full charge and write it down until you have a baseline of what the IR is expected to be for your pack.

All ya need is a multi-meter and consistency.

This is why if you build a pack you test IR of all your cells, including voltage. Not that hard to weed them out before building, really easy to skip this and wonder why a pack is a bum pack.

I’ve probably charged my battery 50-60 times without any issues. Board has done around 1000km total with this pack. It’s secured with Velcro and added foam between the battery and deck to minimize vibrations. Maybe it’s good once in a while to remove the heatshrink just to inspect for damage and such.

Don’t know the brand of the bms but I know that it’s not bypassed and rated for 4A continuous and 80A burst. I just seems that people are measuring each cells quite often… I’ve never done that and don’t know if I should.