Most modern Rolex watches are powered by a self-winding mechanism, which uses the movement of the wearer’s wrist to wind the watch and keep it running. This means that the watch does not require a battery and can run indefinitely, as long as it is worn regularly. However, some older models of Rolex watches may use a battery, and some newer models may be equipped with additional features, such as a quartz movement or a chronograph, that require a battery to operate. It is always best to refer to the specific model and reference number of the Rolex watch in question to determine its power source.