Battery-powered electric razors

Since at least the mid-1960s, battery operated hair clippers have been available using rechargeable batteries sealed inside the razor's case, previously nickel cadmium or, more recently, nickel metal hydride. Some modern shavers use Lithium-ion batteries that do not suffer from memory effect. Sealed battery adjustable hair trimmer either have built-in or external charging devices. Some shavers may be designed to plug directly into a wall outlet with a swing-out or pop-up plug, or have a detachable AC cord. Other shavers have recharging base units that plug into an AC outlet and provide DC power at the base contacts (eliminating the need for the AC-to-DC converter to be inside the razor, reducing the risk of electric shock).