” Lithium batteries. Lithium is a highly water reactive metal. That why you can’t throw them out in the trash. They set garbage trucks on fire. “
I’ll bet virtutaly none of the American public knows that. I sure didn’t.
It’s not the chemistry, it’s the current. Salt water causes short circuits. I lithium ion battery can can generate massive currents and the heat that accompanies that. They will vaporise their surroundings.
It is when the battery case is breached and the contents contact water. Search Youtube for “lipoly fire” or similar and you will see dramatic (and scary) examples. The different lithium battery chemistries do vary somewhat in their propensities to catch fire (looks like an explosion).