Originally Posted by
cwatters
Bit concerned about that last bit. Is it possible that water is fine initially but not ok after the battery has burned for awhile and damaged it's casing?
That is probably not because of risk of fire but rather because the electrolyte in these cells contains a phophor lithium alloy which produces hydrofluoric acid when getting in contact with water.
You want to make sure to keep some distance to the burning cells (which you want to do anyway
) and not to inhale it directly. That could be a bit of a problem when a huge mass of these cells has to be extinguished in a closed encapsulation (read fuselage). 70 lbs of batteries could potentially be a problem in that regard.