A solar-powered watch or light-powered watch is a watch that is powered entirely or partly by a solar cell .
Some of the early solar panels of the 1970s had to be synthesized by solar panels (Synchronar, Nepro, Sicura and some models by Cristalonic, Alba, Rhythm, Seiko and Citizen). In the 1990s, Citizen started to sell light-powered watches under the Eco-Drive series name. Since their introduction, photovoltaic devices have greatly improved their efficiency and their capacity. Watchmakers have developed their technology so much that they are solar-powered. Several other watch manufacturers offer such watches or are developing such technology. These other watch manufacturers include (among others) Junghans ,Casio , Seiko , and Orient .      
Typically, sunlight and artificial light are absorbed by a solar panel behind the crystal. The dial is either on a layer above or actually on the solar panel. This solar panel converts the light into electrical energy to power the watch. The watch will usually be a rechargeable battery pack when it is worn or worn out (eg, sleeve). Citizen’s watches use lithium-ion batteriesto be able to save energy for a few months / years without light exposure, by allowing the watch to enter a power-saving or hibernation mode during which the second hand of the watch is re-exposed to light. Not all have a power-save mode, yet will still hold a charge for typically six months, as with uncomplicated (date only) analog versions made by Citizen.
Inexpensive solar-powered watches were first born in the 1980s and were popular among children, often featuring such fictional characters as Transformers or GI Joe . [ quote needed ]
- Jump up^ Orient Light-Powered Watches (Global Market), Accessed 28 September 2014
- Jump up^ Orient Light-Powered Watches & Movement Manual (Global Market), Accessed 28 September 2014
- Jump up^ List of Orient Watch Manual & Movement (Global Market), Accessed 28 September 2014
- Jump up^ Orient Light-Powered Watches (Japan Domestic Market), Accessed 28 September 2014
- Jump up^ Orient Light-Powered Ladies Watches (Japan Domestic Market), Accessed 8 October 2014
- Jump up^ List of East Watch Manual & Movement (Japan Domestic Market), Accessed 28 September 2014