The DEWALT DCB118 Fast Charger is a fan-cooled charger designed to reduce charge time. This charger can re-charge both 20V MAX and FLEXVOLT battery packs. The DCB118 can charge a DCB606 FLEXVOLT battery in one hour. The FLEXVOLT 20V/60V MAX Battery pack changes voltage when you change tools, powering a line of powerful 60V MAX tools, 120V MAX tools, and backwards compatible to existing 20V MAX tools and chargers. The battery pack is smart enough to know when to provide runtime for 20V MAX tools (6.0Ah) and power in 60V MAX and 120V MAX tools.