Lithium ion batteries don&#x27;t actually contain that much lithium by mass. Lots of water is indeed the recommended approach to dealing with Li-ion battery fires.<p>The lithium in the batteries is far less of a concern than the magnesium used elsewhere in the car. If that gets hot enough to ignite, then you&#x27;re going to have a very hard time putting it out (though the approach to burning magnesium in car fires (which is actually pretty common) is still water, water, and more water).