The BOSTITCH BTC480LM 18v Lithium Ion Battery Lithium Ion features no memory and minimal self discharge so the battery holds a charge longer when stored. This battery pack is also equipped with overload protection. It is also light weight to help minimize fatigue. This 18V battery operates all Bostitch 18V power tools. No memory and minimal self discharge so the battery holds a charge longer when stored Light weight to help minimize fatigue.