Is a solar watch better than an automatic watch?

By Matthew Joseph Nandirio •  Updated: 10/11/21 •  9 min read

Every morning, the margin of the competition in the manufacturing companies is increasing. Every manufacturer seeks to deliver the best products in the market, which means more customers and profits, which is no different from the manufacturers of automatic and solar watches.

These two products have been significantly improved to give a good user experience, comfortable straps, and extra readings such as the compass directions. Consequently, it does not surprise that everyone wonders if a solar watch is better than an automatic watch.

Solar Inverter
Solar Inverter

Nonetheless, we want the best between the two. In other words, we want a watch that does not give trouble when recharging, is easy to read, light in weight, and quite comfortable. If that is your quest, congratulations, you are in the right place.

Unlike others, we will unbiasedly discuss these two products, dig deeper into their construction and merits before we help you conclude. Apart from that, we will suggest some of the watches that we believe will make you grateful for your decision.

What is an automatic watch?

An automatic watch or self-winding watch is an improved mechanical watch with a mainspring instead of a battery. It monitors the natural movements of the wearer to provide energy to wind the mainspring, thus the name self-winding automatically.

These watches were invented at the end of 1973 by Joseph Thustos to abolish the manual winding of mechanical watches. Mechanical watches use batteries and do not have motion sensors to initiate the self-winding process. Thus they require the user to wound them manually and regularly. Thus, the automatic watches were to remove all those hassles.

Next, let us look at the operations of the automatic watches. A self-winding watch has an oscillating weight that triggers the pivot. When the wearer changes their physical position, the rotor pivots on the staff. These motions are passed through a series of reverser and reducing gears, converting the motion to a circular motion.  Next, the circular motions are converted to energy which is used to wind the mainspring automatically.

Some of these watches are made to wound when the weight oscillates in only one direction, while others are advanced to detect both the clockwise and anti-clockwise movements and wind the wind spring in both cases.

As a result, these automatic watches might be in danger of over winding, resulting in excessive tension on the mainspring, breaking the mainspring, or worse cause “banking” or “knocking” problems. How are they wired to solve the over winding problem? Automatic watches have a slipping clutch device on the mainspring that stops the continuous winding of the mainspring. Consequently, the mainspring cannot be broken by excessive winding.

 What is a solar watch?

As its name suggests, solar watches are watches that use light to recharge their batteries. These watches were invented in the 1970s with photovoltaic cells which absorb light energy.

However, its name misleads most people to think that this watch is only recharged with solar light, which is not the case. Instead, its panel is advanced such that it can produce energy from any light. Consequently, besides sunlight, these watches can be recharged on exposure to incandescent or fluorescent watches.

It has an exposed solar panel on the surface that absorbs the artificial or sunlight. The light is passed through the photovoltaic cells, which converts it to electric energy.

The electrical energy is used to power the watch, and some of it is used to recharge the battery for later use. Most solar watches use high-quality batteries such as lithium-ion batteries, which can store sufficient power and store a reliable amount of power that can last for weeks even without exposure to the sunlight.

Also, in some cases, the solar watches may have a power-saving mode triggered when the power drains to a certain percentage. This mode stops the second hand until the watch is exposed to light. Coupling their high-quality batteries and power-saving mode, these watches can last for over six months, even without exposure to light.

Automatic vs. solar watches

The automatic and solar watches were all invented to solve a specific problem. For instance, solar watches were invented to avail self-recharging watches, which significantly increased the longevity of watches. On the other hand, automatic watches were invented to remove the hassles of manually winding the mainspring.

Considering that each of these items solves a specific problem, it might be hard to choose between them. To simplify our work and avoid biasness let’s compare their designs.

Automatic watchSolar-powered watch 
1.    No battery is required. Hence, it is highly reliableUses a solar recharging battery.
2.    There are more accurate than solar watchesTheir accuracy is slightly lower than of the automatic watches
3.    It is a self-winding watch. Hence, no manual work needed to set the mainspringSome of the solar watches may require manual  winding
4.    They may stop working when not wornThey do not rely on the motions of the user. Hence, they will not stop working even when not worn.
5.    The initial price is quite highSolar watches are more affordable than automatic watches
6.    They may lose accuracy over time which might require you to turn it regularlyOn the long solar watches are more reliable

Let’s get into the matter!

Choosing between the two watch construction technologies can be an endless debate, but allow me to share my piece of thought. I would highly recommend the solar watches. What are my reasons?

The most critical things to consider in a watch are accuracy and good user experience. For the first few days after purchase, most people would argue that automatic watches are more accurate than solar watches, which is true. However, let’s look at the flip side.

Automatic watches stop working when stored for some time which will force you to turn them. Besides, reviews suggest that the accuracy of these watches decreases with time.

When it comes to solar watches, they retain their accuracy in the long run. Nonetheless, they have a very minimal error which is quite insignificant. Therefore, solar-powered watches are the best if you want a watch that will serve for several months without decreasing its accuracy.

Additionally, solar watches are more affordable than automatic watches. Even better, modern solar watches are powered with high-quality batteries that might not need replacement on the product’s entire lifetime. Hence, the maintenance cost of the solar watches is also affordable.  

The best solar watches to try

  1. Casio men’s solar sports watch

This solar watch outstands thousands of others in the market with a multilingual system, an auto-calendar, and 5 daily alarms. The multilingual feature gives more than five languages which consist of English, Portuguese, and Spanish. Further, if you need a watch that can act as your reminder, it supports up to 5 alarm settings and even has a countdown remainder.

Additionally, this watch gives the best comfort. Its resin band does not fade and has a slightly thick buckle closure, and is quite easy to tighten. Even better, this watch is 100% water-resistant. Thus, while going swimming or diving, you do not have to remove it.


  • Up to five alarms
  • Analog-digital display which is quite easy to read
  • The resin case is quite durable and does not fade
  • 100% water resistant for divers and swimmers.

2. Casio men’s G-shock solar watch

When looking for a solar watch, it is important to ensure that it has a durable battery and its battery is powerful to last for a few more days, even without exposure to light. This highlighted watch beats the others with an enhanced battery system. Its battery can last for up to 9 months when fully charged. Besides, it has a battery indicator t alert you when the battery is low.

To add to that, this watch has up to 4 alarms which even support the snooze feature. It is improved with a countdown timer, stopwatch, and a full auto-calendar if that is not enough. Thus, its design ensures you are up to your schedule. Additionally7, if you want an elegant watch that will last for decades, this is the best choice. Besides its water resistance capability, its straps are of tear and wear-resistant material for durability.


  • 9 months battery
  • 200m water-resistant watch
  • Supports countdown feature and up to 4 alarms
  • A low battery indicator and supports the power saving function

Final words

Every day, manufacturers brainstorm how to innovate their products to give them groundbreaking capabilities that have not been seen before. As is the case, the automatic and solar watches have been significantly improved with the best features that offer the best user experience. Consequently, choosing between the two might be the hardest task.

Automatic watches are enhanced with sensors that trigger self-winding. On the other hand, the solar watches have an inbuilt solar system that recharges the battery. Hence, you are not likely to run into low battery problems.

Choosing between the two mostly depends on your preference. However, most people choose solar watches over automatic watches due to their affordable cost and reliability in the long run.

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Matthew Joseph Nandirio

Matthew Joseph Nandirio is the Founder of walkingsolar. After graduating from the University of Houston in 2002, matt started working as an electrical and electronic engineer for several multi-national solar energy companies. He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research. He now shares his 20 years of expertise through his articles on the walkingsolar website. Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.