Eco-Drive watches are a special form of solar watch, which the Japanese watch manufacturer Citizen developed with the Eco-Drive technology. These wristwatches generate the required energy through sunlight, heat, movement and - e.g. in the office - through artificial light. Eco-Drive watches therefore do not require a battery. A full battery charge enables most Eco-Drive watches to run for six months in a dark environment.

Citizen Eco-Drive watches