The FLEXVOLT® 20V MAX* / 60V MAX* 15AH battery 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.