The Makita 4.0 Ah battery offers maximum run time for prolonged, heavy-duty applications. 4.0 Ah battery offers 33% increased run time versus 3.0 Ah batteries with no added weight or bulk. LED charge level indicator displays approximate remaining battery power. Battery Protection System provides Over-Discharge, Temperature and Current Protection for enhanced performance, battery cycle life and overall battery life (when used with STAR marked tool). Li-Ion Batteries offer extended run time versus Ni-Cad and Ni-MH batteries.