Solar-powered watch

A model produced from 1978 by the Riehl Time Corporation was simply described as running on solar power, but having "silicon power cells" that "absorb energy from natural sunlight, daylight, or an ordinary light bulb".{{Cite journal |date=December 1978 |title=EEs' tools & toys |url=https://ieeexplore.ieee.org/document/6367774 |journal=IEEE Spectrum |volume=15 |issue=12 |pages=16 |doi=10.1109/MSPEC.1978.6367774 |s2cid=34555837 |issn=1939-9340}}

Some of the early solar watches of the 1970s had innovative and unique designs to accommodate the array of photovoltaic solar cells needed to power them (Synchronar, Nepro, Sicura and some models by Cristalonic, Alba, Rhythm, Seiko and Citizen). In 1996, Citizen started to sell analog light-powered watches under the Eco-Drive name.{{cite web |last1=Bernardo |first1=Mark |title=Citizen Watch Review: Brand History and Highlights from the Modern Collection |url=https://teddybaldassarre.com/blogs/watches/citizen-watch-review |website=Teddy Baldassarre|date=23 June 2023 }} Since their introduction, photovoltaic devices have greatly improved their efficiency and thereby their capacity. Watchmakers have developed their technology such that solar-powered watches had by 2009 become a major part of their range.{{Cite journal |last=Harris |first=Anne |date=2009 |title=Watching the clock - [manufacturing watches] |url=https://ieeexplore.ieee.org/document/5160835 |journal=Engineering Technology |volume=4 |issue=9 |pages=60–61 |issn=1750-9637}} Several other watch manufacturers also use solar technology, such as Orient.[http://www.orient-watch.com/products/category/?category_id=9 Orient Light-Powered Watches (Global Market)], Accessed 28 September 2014[http://www.orient-watch.com/img/manuals/AHc.pdf Orient Light-Powered Watches & Movement Manual (Global Market)], Accessed 28 September 2014[http://www.orient-watch.com/support/manuals/ List of Orient Watch Manual & Movement (Global Market)], Accessed 28 September 2014[http://www.orient-watch.jp/product/category/?category_id=62 Orient Light-Powered Watches (Japan Domestic Market)] {{webarchive|url=https://web.archive.org/web/20141008162740/http://www.orient-watch.jp/product/category/?category_id=62 |date=2014-10-08 }}, Accessed 28 September 2014[http://www.orient-watch.jp/product/category/?category_id=68 Orient Light-Powered Ladies Watches (Japan Domestic Market)] {{webarchive|url=https://web.archive.org/web/20141008162756/http://www.orient-watch.jp/product/category/?category_id=68 |date=2014-10-08 }}, Accessed 8 October 2014[http://www.orient-watch.jp/support/manuals/ List of Orient Watch Manual & Movement (Japan Domestic Market)], Accessed 28 September 2014 Junghans, Casio, and Seiko.{{Cite web |title=Solar {{!}} Seiko Premier {{!}} Brands {{!}} Seiko Watch Corporation |url=https://www.seikowatches.com/global-en/products/seikopremier/seikopremier-solar |access-date=2022-04-07 |website=www.seikowatches.com |language=en}}{{Cite web |date=2021-04-20 |title=The 12 Best Solar-Powered Watches For Men |url=https://hiconsumption.com/best-solar-watches/ |access-date=2022-04-07 |website=HiConsumption |language=en-US}}

Inexpensive solar-powered watches were first sold in the 1980s and were popular amongst children, often featuring famous fictional characters such as Transformers or G.I. Joe.{{citation needed|date=August 2009}}

Image:Casio Tough Solar Wave Ceptor.jpg solar-powered watch, manufactured no later than 2009]]

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 a wearer's clothing (e.g., sleeve). Citizen's watches use lithium-ion batteries to store sufficient energy to power the watch for up to five years without light exposure, by allowing the watch to enter a power-saving or hibernation mode during which the seconds hand stops until 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.

The solar-powered watches has a number of advantages:

• Eco-friendly: solar-powered watches reduce dependence on disposable batteries, helping to conserve the environment and reduce e-waste.
• Low maintenance requirements: because solar-powered watches use rechargeable batteries, they need to be charged less frequently than traditional battery-powered watches.{{Cite web|title=Do Solar Watches Need Batteries?|url=https://solarpowercoast.com/do-solar-watches-need-batteries/|access-date=2025-03-24|work=solarpowercoast.com}}{{Cite web|title=What Is Solar Watch|url=https://weisenwatch.com/blog/what-is-solar-watch？/|access-date=2025-03-24|work=weisenwatch.com}}
• Continuous operation: with the right light, the solar-powered watches can maintain a constant supply of energy, allowing continuous operation without the need for manual recharging or battery replacement.
• Charging indicators: many solar-powered watches are equipped with charging indicators that show the charge level or when the watch is actively charging, providing users with information on the state of charge.{{Cite web|title=How Does a Solar Watch Work?|url=https://walkingsolar.com/how-does-solar-watch-work/|access-date=2025-03-24|work=walkingsolar.com}}

Overall, the solar-powered watches combines the functionality of accurate timekeeping with eco-friendly technology.{{Cite web|title=How Do Solar Watches Work?|url=https://techwriteredc.com/how-do-solar-watches-work/|access-date=2025-03-24|work=techwriteredc.com}}

Disadvantages of solar-powered watches:

• The initial cost may be higher than traditional watches.{{Cite web|title=How does a solar-powered watch work?|url=https://www.bluettipower.com.au/blogs/knowledge-base/how-solar-powered-watch-works|access-date=2025-03-24|work=www.bluettipower.com.au}} One of the biggest disadvantages of solar-powered watches is their initial cost. These watches tend to be more expensive than their traditional counterparts because of the advanced technology used in their manufacture.
• Requires sufficient exposure to sunlight to maintain charge.{{Cite web|title=Solar Watches Pros and Cons|url=https://watchranker.com/solar-watches-pros-and-cons/|access-date=2025-03-24|work=watchranker.com}} One of the most significant disadvantages of solar-powered watches is their dependence on sunlight.{{Cite web|title=Pros and Cons of Solar Wristwatches|url=https://www.studiosuits.com/blogs/articles/pros-and-cons-of-solar-wristwatches|access-date=2025-03-24|work=www.studiosuits.com}} Without sufficient exposure to sunlight, this watch will not be able to charge the batteries and therefore will not work.

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Category:Applications of photovoltaics

Category:Solar-powered devices

Category:Watches

Category:Photovoltaics