The BatPack is a tier one unit that can be used to provide power to any Industrialcraft 2 Tools. To do so the pack must be equipped in the chest slot, it will then provide power to things such as a Drill, Diamond Drill or Chainsaw.
In order to charge it, it must be placed inside something like a Solar Panel or a BatBox. A tool is used that is in any stage of discharge, using it with a BatPack equipped will charge it as much as the BatPack can (full if possible).