If you’re getting seawater in your battery compartment you’re in a world of hurt anyway, and the type of battery probably doesn’t matter much.
“If you’re getting seawater in your battery compartment you’re in a world of hurt anyway, and the type of battery probably doesn’t matter much.”
I am going to hypothesize that they are in sponsons outside the sub’s air compartment and that they are in nearly indestructible individual cases. I wonder what effect a nearby explosion would have on them. Also, if they are small and hooked together each connection becomes an additional point of failure. As to charging them either a nuclear battery (a type of dry-cell except it generates charge) or a fuel cell would do a nice job.