The Battery CBM requires you to go directly into the inventory menu and manually use the “Eat” command, sort of like how you used to be able to (can still??) with storage batteries. That was with a medium battery, I’ll see what it’s like with other battery types.
Edit: same with all battery types as far as I can tell, not had chance to test with a storage battery yet so dunno if it’s still the same with them but it’s not really an issue when you have disposable batteries of 2500 upward and rechargables of 1250 upward.