@kain preacher
These are Li-ion cells, i.e., salts of Lithium in solution. There is no metallic Lithium anywhere in or near those batteries. While the other chemicals involved are pretty volatile, what you get in a battery fire is not a "metal fire" but a pretty much self-sustaining, rapid exothermic reaction of the components of the battery. Since it is self-sustaining (i.e., does not need external oxidisers), pouring water onto the ongoing mess will not add significantly to the reaction. As noted by others already, it will cool down the mess and thereby reduce the total amount of damage.
Biting the hand that feeds IT
