The Bosch GBH18V-26K24 kit pairs the CORE18V GBA18V63 18V 6.3 Ah Battery with the 18V EC Brushless 1 In. SDS-plus Bulldog Rotary Hammer to deliver more power in a lightweight, cordless tool. When put to the drilling test in concrete, the CORE18V battery enabled extra power in the GBH18V-26 rotary hammer, delivering up to 32% more holes, even in extreme cases, than previous-generation 18V 6.0 Ah battery. The cells in the CORE18V carry more energy density than the previous-gen cells, and they are laser-welded and rail-connected for high-current efficiency. They deliver performance comparable to competitive batteries up to 35% larger. The included Bosch BC1880 18V Fast Charger can charge a spent CORE18V to 80% in 41 minutes and to 100% in 55 minutes.