New York

If they develop an internal short, are charged too quickly, or just get too hot they can burst into uncontrollable flames or explode.

And once they do that, they are just about impossible to extinguish.

If you accidentally may have damaged one of these batteries—for example, by dropping it—, DO NOT USE IT. Get it inspected and replace it if it doesn’t test properly.

And NEVER use an unauthorized charger for these things. NEVER store these batteries in a location that is inaccessible or that blocks an exit. I’ve seen these things cook off. They are not a joke.