The DeWalt DCB612 12.0 Ah FlexVolt battery, packing about the power… When you’re unfamiliar with their FlexVolt technique, they’ve generally designed a battery that could detect whether or not the tool it’s in needs 20V or 60V, and adapt appropriately.Speedily charge 20V MAX* and 20V/60V MAX* FLEXVOLT® batteries with this 12 Amp Fast Charg