> When battery packs that have a non-zero chance of literally killing your users are commonplace, it actually does make sense to vendor-lock the battery.

Linus from Linus Tech Tips made a few episodes on building a battery out of individual 18650 cells, and one of the thing he stressed (as in, underlined) a lot on is that spot-welding cells is extremely dangerous and there aren't easy ways to put out a lithium fire.

Water is not only not going to help you, it's going to make things worse.

You __have__ to have a bucket of sand with you and if anything goes even slightly wrong you just toss everything in the bucket of sand and bring the whole bucket outside.

Went and found the LTT video. It's unclear what he did there. He said there was a spark, and then he ran outside with his pack. Spot welding the cells isn't usually that fraught.

Yeah burying a thing in sand is legit. Depending on the size of the thing that's on fire, water might be fine. Standard protocol for electronics that catch fire on a plane is to apply water to cool the device and extinguish materials around it, and then to put it in a special fireproof bag with a bunch of water.