Shop Wise Line Tools for Dewalt Flexvolt Batteries. Switch your tools, not your batteries. Dewalt FLEXVOLT® Batteries work with Dewalt's 20V MAX* tools and Dewalt's most powerful cordless tools. They automatically shift voltage when you switch tools. Get the power of a corded tool in 60V MAX* and 120V MAX* tools, and increased runtime in 20V MAX* tools.