The Bosch Core18V 2-Battery Starter Kit (6.3 Ah) (GXS18V-02N24) gets users started with unleashed power and productivity. The Core18V series batteries provide 80% more power and 20% longer runtime than previous generation batteries and are backwards compatible with previous generation tools. The included BC1880 18V Fast Charger can charge a spent Core18V battery to 80% in 41 minutes and to 100% in 55 minutes. The charger has a dual-mode charge – the first 80% is very fast, while the remaining 20% is in regular mode.