If that short circuit became a genuine Battery fire...with the resulting problems of heat, smoke, and poisonous gases....driving the crew topside....in those seas and temperatures?
If it was/is on the surface...why is it so hard to find?
If it had a battery issue....why would it submerge having been on the surface and reporting the problem?
Lots of questions....hopefully the crew can be found safe....but each hour lessens the chances of that happening.