The Bosch GBA 36 V 4.0 Ah H-C Professional Battery is a powerful battery with Cool Pack technology. This technology means it has a minimum 50% longer runtime than a 2.6 Ah battery & up to 100% longer lifetime than a battery without Cool Pack. The Bosch flexible power system means this battery is suitable for all the tools in one Voltage class & it is extremely tough, even surviving a 3m drop onto concrete.