Solar powered watch

A solar powered watch is a watch that is powered entirely or partly by a solar panel.

Some of the early solar watches of the 1970s had innovative and unique designs to accommodate the array of solar cells needed to power them ( [http://www.ledwatches.net/articles/synchronar_review.html Synchronar] , Nepro, Sicura and some models by Cristalonic, Alba, Seiko and Citizen.In the 1990s, Citizen started to sell light powered watches under the the Eco-Drive series name. They have developed the technology such that solar powered watches are now a major part of their range of watches. Several other watch manufacturers offer similar watches or are developing such technology. These other watch manufacturers include (amongst others) Junghans, Casio G-shock and Casio Oceanus.

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 store energy in a rechargeable cell to power itself during the night or when covered such as by a person's sleeve. Citizen's watches use lithium-ion rechargeable cell to store sufficient energy to power the watch for several months/years of darkness. However, this figure assumes that the watch enters a power-saving mode during which the seconds hand stops until the watch is re-exposed to light.

In the 1980s, inexpensive solar powered watches hit the market and were popular amongst children, often featuring famous fictional characters such as the Transformers or GI Joe.

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