All power toothbrushes marketed today are powered in one of two ways: 1) disposable battery-operated; or 2) rechargeable power source.
Disposable Battery-powered Toothbrushes
Lower cost, replaceable (disposable), battery-operated toothbrushes utilize built-in AA batteries so that the batteries can be replaced when worn down (on some models) or the entire toothbrush discarded. The brush head can sometimes be replaced, depending on the model. As the battery life is reduced, the toothbrush speed also reduces.
Rechargeable Powered Toothbrushes
Power toothbrushes with rechargeable batteries are charged by sitting on a stand that is connected to an electrical outlet. Patients keep the handle, but replace the brush head optimally every three months. The speed of these brushes varies from low to high, with the variance dependent on the manufacturer and type of brush.