The BOSCH GXS18V-15N15 CORE18V Starter Kit with 4.0AH Compact Battery delivers next-gen battery performance and a charger. The CORE18V Compact Battery is the next-gen Lithium-ion battery to keep the power and runtime, while losing the weight. Engineered with 21700 cell technology, the GBA18V40 single-layer battery matches the power from the original two-layer 4.0 Ah battery with improved performance per cell. The Bosch GAL18V-40 charger can completely charge a discharged CORE18V 4.0 Ah battery to 80% in 48 minutes and to a full charge in about an hour. This BOSCH GXS18V-15N15 CORE18V Starter Kit with 4.0AH Compact Battery charges the first 80% in standard charging mode and the remaining 20% in long-life mode getting users back to work quickly. BOSCH GXS18V-15N15 CORE18V Starter Kit with 4.0AH Compact Battery features charging indicator lights showing when the battery is in standard mode, long-life mode or finished charging. The battery provides exclusive CoolPack 2.0 technology to manage the heat of the higher power-density cells, and it provides better cooling than the previous 4.0 Ah double-layer versions.