Once the room is clear grab the battery again and take it through the door to the Mess Hall near the letter "A" on the wall. This leads to a powered-down elevator. Slot the battery into the wall to activate it, then ride it up.
Once the room is clear grab the battery again and take it through the door to the Mess Hall near the letter "A" on the wall. This leads to a powered-down elevator. Slot the battery into the wall to activate it, then ride it up.