Watch Mechanics: How do Solar watches work?

It would have been so good if a watch didn’t need to change the battery, right? You could have used the watch for years. And imagine that watch being eco-friendly. How great that will be? Do you think there is a watch with these features?

Yes. A solar watch is a watch that doesn’t require a battery or daily winding. It’s also an eco-friendly watch. It is essentially a conventional quartz watch with a rechargeable battery rather than a disposable one, making it far more accurate than conventional mechanical movements. But have you ever wondered - how do solar watches work?

Basically, a solar watch uses sunlight to power the timepiece. It has a solar panel placed under the dial which absorbs solar power and converts it to electronic energy to move the watch. The energy is stored in the rechargeable cell to power itself even in darkness. 

If you want to get a solar watch, you should know everything about it. By the end of this post, you will get all the necessary information regarding this magnificent creation. I’ve also added some answers to some commonly asked questions. So read through this article if you are interested in this watch.

How do Solar watches work

Salient Features of a Solar Watch

Solar watches are typically built to be modern and have a variety of functions. Many solar watches highlight their endurance by including a stopwatch, various time-zone displays, power save mode and, water-resistance up to 200 meters. The majority of modern solar-powered timepieces contain secondary batteries.

Some solar watches have an LCD that includes a barometer, compass, thermometer, and altimeter. Solar watches are tough, with stainless steel or titanium casings and toughened mineral or sapphire crystals on many of them.

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Pros and Cons

Before getting a solar powered watch, you should definitely know what advantages and disadvantages you can get from a solar watch. So we've added them below:


  • Need low maintenance
  • Very accurate time-keeping
  • A massive power reserve can be obtained from a single charge.
  • Have an extended battery life
  • Environment-friendly
  • Water resistance up to 200m


  • Have low beat rate than mechanical watches
  • Expensive than normal quartz
  • Needs light source to charge solar panels

How Long Does a Solar Powered Watch Take to Charge?

It takes about 3 hours of direct sunlight to fully charge most of the solar watches and even in complete darkness, a full charge endures about 6 to 12 months depending on the watch. However, a modern solar-powered watch doesn't need a long light exposure. A quick charge of 3 minutes will let the watch work for the next 24 hours.

Your solar-powered watch can also be charged indoors by the light from a fluorescent lamp or incandescent lamp. However, converting artificial light into energy takes more time which means charging your solar-powered watches with artificial light will take prolonged periods of time than charging it with the sunlight. It could take up to 150 hours to complete the process. Depending on your watch, it can be charged by UAV or LED lights.

How long do Solar Watches Last?

The fact that a solar timepiece gets charged whenever it is exposed to any source of light means that the watch lasts l forever. Solar watches contain batteries that don't need to be replaced as they can typically last for more than 10 years.

There has been a massive improvement in efficiency and battery storage since the launch of early solar-powered watches. Back in the day, solar energy used to last 24-48 hours. This, however, is no longer the case. These watches only require a few hours of daylight exposure to charge to 100%, and a quick charge of a few minutes of artificial lighting at a time will sustain their energy for over a couple of months.

Normal quartz watches have batteries that only last up to 2 years. Even after 20 years, a solar-powered watch battery has been demonstrated to preserve up to 80% of its power reserve capacity. So, in the long run, solar-powered watches are definitely the better choice.

Solar powered watch
A solar-powered watch by Pat Taylor

Solar vs Automatic vs Quartz: Which One is Better?

Solar timepieces are nearly always a better option than quality quartz watches. But it is difficult to compare solar watches to mechanical/automatic watches, which provide a fundamentally different experience.  

Solar watches are far more accurate than mechanical watches, and they have far longer battery life. So, they are the obvious choice in terms of practicality. Automatic watches, on the other hand, have a smoother second hand, which is more aesthetically appealing, as well as, arguably, a higher sense of craftsmanship due to the intricate mechanism inside.

If you are not a conscientious person who dislikes having to manually wind your manual watch every time you put it on or having to replace your watch batteries every few months, then solar-powered watches are a perfect choice for you.

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Frequently Asked Questions

If you have read all the information above, you should have a clear idea about a solar watch by now. But you should also know what people like you ask about this topic. So I’ve added some below: 

Are Solar Watches Hard to Maintain?

Keeping a solar watch functioning does not need much effort. It will be decades before you need to worry about any kind of maintenance for a solar watch. A solar-powered watch, unlike a manual wind (which must be wound on a regular basis) or an automatic watch (which requires motion), need just light to operate. You don’t have to change the battery for more than 10 years.

How Solar-Powered Watches are Eco-Friendly?

If you want a green hand, a solar watch is a watch you should get because solar watches do not require battery replacement every few years, so they help the environment by minimizing the usage of disposable batteries which causes environmental pollution. Solar watch batteries are fully rechargeable and powered by a natural source of energy.

Every year, about 300 million quartz-powered timepieces are made, with batteries lasting an average of two years. We could save at least 300 million batteries each year if all of these watches used rechargeable batteries! Consider the consequences. 

Can You Tell What the Charge Level is?

Yes. Most solar watches include some sort of added functionality that will notify you when your battery is low on charge. A power level visual indicator is usually included in the display of solar-powered digital timepieces. However, this can vary from model to model so the manual will be extremely informative.

Can You Overcharge a Solar Watch?

No, you can’t. If you could overcharge the watch, it would damage the battery. That’s why solar watches have overcharge protection which ensures the lithium-ion battery remains unaffected when the watch is exposed to any light source after it has been fully charged.

Final Thoughts

So basically, a solar watch needs sunlight or artificial light to keep working. Just you will have to place the solar watch where sunlight is available and the solar cell will absorb the light energy and convert it to electrical energy to move the watch. The sufficient energy stored in the rechargeable battery helps it to show the time at night.  

If you want a quality accurate watch that you can use for a long time without changing the battery and helps the environment, a solar-powered watch is what you are looking for. Although a solar watch is expensive than typical quartz watches, I think this watch is worth its price. Solar watches literally last forever because it gets charged whenever it is exposed to light.

I hope this article cleared all your confusion and answered all your questions. If you have any more questions, ask in the comment section below.