Everything you need to know about a solar watch

A solar watch combines the long lifespan of a mechanical or automatic timepiece with the accuracy of quartz. This type of watch is becoming increasingly popular; Sustainable solar energy is hot! But how do solar watches work? What are the benefits of solar? And are they really that sustainable? In this blog we answer all your questions.

How does a solar watch work?

Just like quartz watches, solar watches operate on (lithium) batteries. Unlike the battery of a ‘normal’ quartz watch, the battery of a solar watch is charged by means of (sun)light.

There are small solar cells in or around the dial of the watch. Light energy is converted into electronic energy via a specially designed photovoltaic system, comparable to the operation of solar panels that are now on many roofs. This energy is stored in the rechargeable battery that powers the timepiece.
Furthermore, a solar watch works in the same way as a traditional quartz watch; with a vibrating quartz crystal in the electronic circuit, which ensures very accurate time indication.

Exploded view Citizen Eco-Drive watch
▴ Exploded view Citizen Eco-Drive watch

Most solar watches also work on artificial light

The name suggests that a solar watch only works on sunlight. But while these watches charge best in natural light, most can also be charged via artificial light. It’s worth checking your watch’s instruction manual for more information on how your specific watch responds to different lighting conditions, as this varies from brand to brand. In general, the brighter and closer the light source is to the watch, the better.

Maserati Successo R8853145514

▴ Maserati Successo Ladies R8853145514

Citizen Promaster EO2023-00A

▴Citizen Promaster EO2023-00A

The benefits of a solar powered watch

Solar powered watches are not only precise and reliable, other advantages are: high quality, durability and functionality. Enough reasons to add a solar watch to your collection.

Reliable: the precision of quartz with the convenience of an automatic

Because the battery of a solar-powered watch is continuously charged, it tells the time reliably and very precisely.

Functional and accurate

Because the energy source is in principle inexhaustible, it is possible to add extensive functions – which require a lot of energy – to the watch. That is why many solar watches contain radio control, GPS or Bluetooth that make the watch even more accurate.

High Quality

To protect the solar cell, solar powered watches are usually made of sturdy materials and are therefore of high quality.

Water resistance

Because the watch almost never needs to be opened to replace the battery, the rubber gaskets that protect the inside against water ingress do not wear out as quickly as with regular quartz watches. This ensures that the water resistance of a solar watch is guaranteed.

Sustainability

Solar watches are more durable than quartz watches with a disposable battery. On average, the battery of a solar watch lasts 7-12 years. These batteries can also be charged hundreds, even thousands of times before a replacement battery is needed. You also do not use mains power, as when charging your mobile phone, but energy from light.

Festina 20660/3 Solar

▴ Festina 20660/3 Solar

Fossil FS5978 Defender

▴ Fossil FS5978 Defender

This makes solar watches sustainable

Although the rechargeable battery of a solar watch lasts a very long time, it is of course still a battery. The production of batteries and the extraction of the materials used to make batteries are quite harmful to the environment. And when the battery is eventually replaced and thrown away, the chemicals can leak out and contaminate soil and water.

However, rechargeable batteries are a more sustainable choice because they require less material. If you maintain your watch properly and, for example, replace the strap instead of buying a new watch, you will be even more sustainable. This means that materials do not have to be extracted and produced again to make your watch.

Or when you buy a new solar watch, choose a watch made from recycled or sustainable materials such as bioplastic or recycled steel. You will mainly find these watches in the Skagen and Casio collections.

Skagen Pine SKW3077

▴ Skagen Pine SKW3077

Casio Pro Trek PRW-6900Y-3ER

▴ Casio Pro Trek PRW-6900Y-3ER

Disadvantages of a solar watch

So far we have only talked about all the benefits of a solar watch. However, there are also a few disadvantages:
With some solar watches, the solar cells are visible in the dial. This is something you need to address. Some people find this ugly, others like to show what kind of watch he or she is wearing.
Solar watches with a battery that lasts less long must be charged more often in the light. But if you ensure that you wear the watch regularly, every solar watch has enough energy to get through the day.

As far as I’m concerned, minor inconveniences compared to the benefits and no reasons not to choose a solar watch.

Casio LCW-M170TD-1AER

▴ Casio LCW-M170TD-1AER Lineage

Seiko Prospex 'Tropical Lagoon' SNJ039P1

▴ Seiko Prospex ‘Tropical Lagoon’ SNJ039P1

What is the lifespan of a solar watch?

With a full battery, a solar watch functions without light for one to twelve months, depending on the brand and model. Some brands guarantee a service life of up to 10 years in power save mode. Even in the dark! With most solar watches, a battery indicator shows when the watch needs light to charge again.

How long does a solar watch need to charge?

Although solar watches can be stored in the dark, it is best for battery endurance to store them in a well-lit place. This prevents the battery from draining completely, which can damage its lifespan.

How long the watch continues to work depends on how advanced the watch is. A watch that only tells the time requires less energy than a watch that has all kinds of other functions. Has the watch stopped completely? Then a few minutes of light is often enough to get the solar clock working again. It takes more time to fully charge the battery.

Average solar battery charging time table*

Light source Charging time for 1 day of use Charging time for completely empty battery
Direct sunlight 10-40 minutes 18 hours
Fluorescent lamp at a distance of 20 cm 1.5 -2 hours 72 hours (3 days)
Interior lighting in surroundings 5-6 hours 120 hours (5 days)

*please refer to your watch manual for charging instructions

Bering 14339-369

▴ Bering 14339-369

Diesel DZ4620

▴ Diesel DZ4620

The best solar watches at a glance

The best brands with solar watches in their collection are Citizen and Seiko. These two Japanese watch brands were and are forerunners in the development of solar energy technology for watches.

Seiko Solar watches

The first solar wristwatch in 1977 was from Seiko and the brand has continued to perfect the technology since then. Seiko Solar watches are still among the most popular in the world.

Citizen Eco-Drive watches

Citizen is also a pioneer in the field of solar watches. The Citizen Eco-Drive system is used in 80% of all Citizen watches. The Citizen L Solar women’s watches are produced entirely from sustainable materials.

Citizen Promaster Sky JY8058-50L

▴Citizen Promaster Sky JY8058-50L

Seiko Astron SSJ013J1

▴ Seiko Astron SSJ013J1

G-Shock Tough Solar

G-Shock watches are almost indestructible, so the brand’s solar technology must also be strong and last a long time. The G-Shock Tough Solar models offer both power and longevity.

Garmin solar smartwatches

Garmin is a producer of very advanced and versatile smartwatches. In every line of Garmin smartwatches you will find models with a regular rechargeable battery and solar smartwatches. For example with the Garmin Instinct. How nice is it when you go out that you don’t have to worry about whether your smartwatch has enough energy for the entire trip?

G-Shock GM-B2100GD-9AER

▴ G-Shock GM-B2100GD-9AER

Garmin instinct Crossover Solar 010-02730-10

▴ Garmin instinct Crossover Solar 010-02730-10

How much does a solar watch cost?

How much a solar watch costs depends on the brand, the materials used and of course the functions, but on average count on 140 to 300 euros.

Solar watches are available at Techzle in all price ranges. You can get a simple plastic digital solar watch from Casio from 60 euros. At the other end of the spectrum you will find solar watches from G-Shock MR-G or the Seiko Astron with extensive functions such as GPS, radio control and Bluetooth, ranging in price from 2000 to more than 6000 euros.

Whatever budget you have, a reliable, accurate and durable solar watch is always a good investment!

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