I've had this a few times and now have a save where I can duplicate it. I've recently installed the top battery onto this derelict i'm flipping. and when i do it seems to somehow stop the other battery from working. Reloading the game/save doesn't seem to affect this.
Both batteries are moderately drained at this moment so it's hard to tell if it's just the info window not working or if the battery isn't delivering power to the ship.
To see this in effect yourself just un-install the top battery and the bottom battery will spring into life. Plug it back in again in the same spot and after a second or two the bottom battery stops working (it still has it's little blue light active).