The Wahl clipper lithium ion® trimmer is the world's first grooming device with lithium-ion technology. It is the most advanced rechargeable battery technology available. It's lighter weight, has almost no charge loss in storage, is environmentally smart, and has no memory issues. Best of all, it provides 3x the run time, 2x the torque, a 1- minute quick charge, and 1-hour full charge which standard NiMH/NICAD trimmers cannot do. Wahl is to trim and shave better.