After today's patch, when I click my bar to activate a battery (shields, engines, weapons, etc.) the stack of batteries disappears from my bar. They remain on my ship in the device slot but do not appear on any of my trays or anywhere in the menus to drag back to the bar.
If you have a stack of items in your Inventory, and need to use them, you can only use the first one. In order to use others, you have to MOVE the stack to another inventory slot, then use another, move stack, use, and so on. Discovered while trying to activate boosters.