How Do Solar Watches Work?

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Solar watches are normally powered by the sun. They gained popularity in the ’70s and even in recent years because they have a temperature, compass, altimeter, and barometer on them. All these features are great for adventures!

Many watch enthusiasts moreover prefer solar watches because they combine the best features of all other watch movements: the accuracy of quartz and the longevity of automatic and mechanical movements. Plus, they’re eco-friendly too!

But in today’s technologically advanced world, do solar watches still function the same way as they did in the past? How exactly do they work?

To learn more about solar watches, how they use the sun’s energy to track time, and the pros and cons of using solar watches, keep on reading.

Benefits of Solar-Powered Watches

Wearing a solar watch is eco-friendly as the timepiece uses a renewable energy source to function, meaning it does not cause any harm to the environment.

These kinds of watches are quite reliable too and perhaps this is its biggest selling factor. It can just charge whether in artificial light or sunlight. You don’t need to replace its battery every few years. (We’ll explain more later why solar watches still use batteries).

The next benefit of solar watches is the minimal maintenance needed to function. It may seem fun to use a wind-up watch at first, but they become difficult to maintain and are quite tedious after a while. 

That is because you need to wind up your watch every day just to keep time properly. Compare that with solar-powered watches that require no special maintenance or winding to function. It will keep track of time as long as you give it the light it needs.

Solar Watches vs. Traditional Watches

Solar watches are sometimes referred to as quartz timepieces that are powered by any source of light through their solar cell. They are designed with a vibrating quartz crystal inside for timekeeping accuracy.

However, solar-powered watches are not the same as traditional quartz watches in terms of battery.

Solar watches have rechargeable batteries while traditional quartz watches are equipped with disposable batteries. 

The rechargeable batteries used in solar watches are usually in the form of lithium-ion cells/ solar panels and can be recharged thousands of times before replacement. Recharging is also effective. One full charge gives the watch a solar power reserve that will last for several months.

How Do Solar Watches Work?

Under the dial of each solar-powered watch is a solar cell that converts light into electrical energy. Such electrical energy is then passed to a rechargeable battery, wherein it can be slowly released to power the watch.

Due to the efficiency of such technology (imagine it is always charging when exposed to light), one full charge is enough to provide months’ worth of power reserve to the timepiece even if it will be later on kept in a dark environment.

But does that mean solar watches last forever? Well, they typically have an extended battery life better than regular quartz watches that needed changing in about 2 to 3 years.

How Long Do Solar Watches Last?

With solar-powered watches, you can expect that they will last for 7 years or more. There were some reports online claiming that solar watches may even function for 20 years without changing the battery. 

Solar watches recharge best when exposed to the sunlight, but it doesn’t mean they can’t be charged with some types of artificial lightning because they do. It’s just that sunlight yields the fastest charging speeds to the solar panels. 

We encourage you to check the manual that comes with your solar-powered watch to know how your specific model will respond to various lighting conditions as it may differ from other solar watches.

[Related post: Best No Battery Watches]

How to know the solar watch’s charge level

Generally, the closer to the light or the brighter the light source is, the better. To know the charge level of your solar watch, check the power level visual indicator in the display. 

If your watch model doesn’t have that display, there may be certain functions linked with the second hand. For instance, the watch ticks will operate in bursts of two, indicating the watch charge level is already low.

Pros and Cons of Solar Watches

Pro: Solar watches can be charged through any light source

A solar watch is always charging once exposed to light.  The light energy received by the solar cell under the dial is automatically converted into electrical energy.

Still, light intensity matters on how fast your solar watch recharges. A bright and sunny day will help with faster charging than cloudy weather or artificial light.

Con: Solar watches are slightly more expensive than other watches

Compared to quartz watches, solar watches are a little more expensive but this is understandable because of the technology behind them. And if you look at it from a long-term perspective, the cost is justified since you won’t need to replace the batteries for the next 7 years or so.

Pro: Solar watches are low maintenance

Solar quartz watches require little maintenance. All they need when it comes to upkeep and care is to keep them in daylight so it never runs out. This lessens your worry of having to maintain it and there are no recurring fees after the initial cost.

Con: Solar watches have large PV cells on the dial that may look inappropriate in a formal dress

Although there is no rule in fashion stating that large PV cells on the watch’s face are a no-no, some people avoid wearing solar watches because of it. They find that the prominent PV cells on the watch’s face do not go well in a formal dress or suit.

Pro: Solar watches have a long power reserved

Don’t you hate it when the batteries of your favorite watch die? Most people do this because they don’t have the right battery or tools to replace it. So, they are forced to make a special trip to the nearby watch shop.

The good news is that with solar watches, you won’t encounter this problem because they all get their energy from the sun or other light sources.

Are Solar Watches Worth It?

Of course, solar watches are definitely worth buying. 

It has a longer lifespan than other watches in the market and they can outperform their timekeeping ability with other types of watches.

[Related post: Seiko Solar Watch Review]

Frequently Asked Questions About Solar-Powered Watches

Can you put a regular battery in a solar watch?

No, you cannot put a regular battery in a solar watch. Since it moves by converting light energy received by a solar cell into electronic energy, it needs to have a rechargeable power cell installed.

Putting a regular battery in a solar watch may damage the device even if it seems to work the first time. If ever you notice a decrease in the watch’s functionality, we recommend you replace it with a power cell, not a regular battery.

How often do you have to charge a solar watch?

A 3-hour charge of a solar watch can last up to six months but some brands combine the features of solar technology and power-saving modes, meaning their watches have high power reserves.

When the solar panel needs to be charged more, the timepiece will usually just signal by moving at two-second increments.

Can you overcharge a solar watch?

No, you cannot overcharge a solar-powered watch. It’s because it comes with protective functions that safeguard the lithium-ion battery against damage that may happen from a light source when it is fully charged.

But keep in mind that overheating is possible with a solar watch. As much as possible, avoid over-exposing the watch to sunlight or artificial light.

Why do solar watches stop working?

There are few solar watches that cannot be recharged in complete darkness. In such situations, the energy may run out. Another reason why solar watches stopped working is that they are usually concealed under a sleeve when worn.

A solar watch can likewise stop working if there is damage in the movement/parts, or it is because of normal wear and tear that can happen after many years of using the timepiece.

But if you notice the solar watch slowing down (not actually stopping), it may be because some parts need fresh lubrication. 

How do you revive a solar watch?

To revive a solar watch, it is important to expose it to light. Simply place the watch by the window with sunlight, the dial facing the sun.

If it doesn’t still work after attempts of recharging it, a repair may be necessary. Your watch may come with a warranty so you can bring it to the brand’s repair center so they will be the one to disassemble the timepiece to access the internal components.

However, most solar watches are designed without user-serviceable parts inside so it is best not just have anyone open it unless they are a certified technician that does the repair work.

[Related post: Most Durable Watches – Top 7 Tough Watches]

Final Verdict: Is a Solar-Powered Watch Right For You?

We hope that this post has at least answered some of your questions or concerns about solar-powered watches. In summary, solar watches are an excellent alternative to traditional timepieces.

They are quite easy to charge, their power cells last longer compared to traditional batteries, and it’s easy to purchase one in whatever display style.

They are worth getting because of the many reasons, such as:

– high reliability

– not expensive

– almost no need for maintenance

– environmental-friendly

– accurate timekeeping

– no need to change batteries

Still not convinced about the benefits of owning and using a solar watch? Do check out Seiko Solar or Citizen-Eco Drive as they are two of the most popular solar watches in the market today.

If you like this review, you might want to read our other reviews at EvesWatch.com.