The Bosch CORE18V Performance Starter Kit (GXS18V-12N14) delivers next-gen battery performance and charger flexibility. This kit features the CORE18V Performance Battery, which delivers 2X the power and runtime as two-layer 4.0 Ah batteries with minimal increase in volume and weight. Engineered with 21700 cell technology, the battery delivers power and performance for high-capacity tools. Bosch engineered the exclusive CoolPack 2.0 technology to manage the heat of the higher power-density cells, and it provides better cooling than the previous-generation CoolPack system. The Bosch 18V charger has regulated dual-mode charging, which fast charges a battery to 80 percent, while the remaining 20 percent is long-life mode. This charger has a charging status indicator and provides a cooling fan to help protect batteries from overheating while charging.