The perfect alternative to standard AA alkaline batteries, the Fenix ARB-L14-2200U is a rechargeable battery that works in many devices that require this type of power. It is the same size and voltage as a standard AA, but has a built in USB Type-C port which allows you to recharge the battery for up to 300 cycles. Better performance with multiple circuit design protections, makes this a much better choice—and is better for the environment.