The DeWalt FlexVolt 20V/60V MAX 15.0 Ah Battery (DCB615) provides the highest capacity of any battery on the DeWalt cordless system.  It changes voltage when going from 20V MAX to 60V MAX tools and is compatible with a variety of 20V MAX tools and chargers.  In 20V MAX tools it will provide extended runtime. In 60V MAX it will deliver cordless 60V MAX power.  Compatible with 20V MAX, 60V MAX and 120V MAX tools and all 20V MAX chargers.