Solar watches are a unique type of watch that relies on solar power to function. Unlike traditional watches, which need to be wound or have batteries replaced, solar watches get their power from the sun.
This makes them a more sustainable and environmentally friendly option for watch wearers. Solar watches come in a variety of styles, colors, and uses…everything from formal accents to rugged timepieces suited for outdoor use.
I have been aware of solar watches for some time but never really dove into how they work or what advantages they have over traditional timepieces. As I started doing a little research I found that the answers I was looking for didn’t always give me the whole picture, so I started compiling the info and putting it together in this article. Check it out!
How Do Solar Watches Work?
In general, solar watches contain solar cells within the dial. These solar cells convert light into power that is stored in a rechargeable battery that drives the timepiece. As it is excellent at improving sun-catching ability, a layer of silicon is frequently placed beneath the face of the watch.
The light stimulates the ‘free electrons’ present within the solar panels. This induces electric current which allows the electrons to carry the energy to the battery where it is stored. The electrons stimulated to generate and transport the current are reused to transport the energy to and from the battery.
The battery, unlike common disposable batteries, such as the button battery or the dry battery, relies completely on light for energy and is thus eco-friendly. The battery is usually in the form of rechargeable lithium-ion cells.
Once the battery is charged, the watch functions like any other quartz watch which is why solar watches are sometimes referred to as ‘solar quartz’ watches. I go into way more detail about solar watch batteries over here in this article.
How Long Do Solar Watches Last?
Generally, a fully charged solar watch will work for up to 12 months before needing to be recharged. The life of a solar watch also varies but the battery is usually expected to last for between 7 – 10 years before expiry, although it is possible for the battery to last for as long as 20 years.
How long a solar watch lasts depends on several factors. Usually, a single charge can power a solar watch for months, even if stored in a dark environment.
The life of the battery and the ability to store light varies from watch to watch, but all will continue to work without exposure to a direct light source provided that the watch has a charge remaining.
How long your watch lasts will depend on the level of charge that it has. A watch’s ability to gather charge from light can be affected by the source of light, the intensity of light, as well as the model of the watch, and the technology it uses.
The battery lasts for ages, upwards of 20 years in some cases, but its life can be prolonged by using it often and storing it in a place with sufficient light so that it can recharge.
The battery’s ability will eventually decline due to corrosion and wear over many years of use. Fret not, for the battery can be replaced at a cost that is only slightly higher than that of the battery used in your conventional wristwatch.
To maximize the long-term charging capabilities of your watch, and for the healthy maintenance of the battery, it helps to store the watch in an area with sufficient lighting. This prevents the battery from completely depleting, which would increase the time needed to recharge the watch, as well as decrease the longevity of its battery.
However, even if your battery is still working, it is advised to change your battery every 10 years or so, as chemical leakage from the battery and other battery-related faults can damage the functions and capabilities of the watch
How Often Do You Have To Charge A Solar Watch?
In most cases, 3 – 5 minutes of direct sunlight will give most solar watches enough charge to last for 24 hours. It takes a minimum of 3 hours of sunlight to fully charge the battery. However, this will give your watch 6 – 12 months’ worth of charge depending on the watch’s battery capacity.
As mentioned earlier, the type and intensity of lighting matter. Sunlight is far more effective than artificial light. Solar watches generally take a full day to charge under artificial light, while it takes only 3-5 hours to charge using natural light.
Plenty of natural light is available throughout the day even when the sun isn’t out. It is actually advised that you do not put the watch under direct sunlight for hours on end as this can damage the battery and shorten the watch’s life. When charging, it is important to point the face towards the source of light.
3 hours of direct sunlight will never be necessary as the battery begins charging as soon as any light hits the solar cells. This is one feature that makes solar power ideal for rugged outdoor-style watches. They will get plenty of sunlight while you’re out hiking or camping…even when not directly facing the sun for extended periods of time.
It is also worth noting that most modern solar watches have a mechanism to prevent the battery from receiving too much charge. When the battery reaches capacity, it simply cuts off the ability of light to store any more energy. This protects the battery from rapid deterioration associated with overcharging.
Some solar watches also give warnings when the charge is low, such as the hand of the watch moving at two-second increments instead of one. Charging rate and capacity varies between watches so make sure that you know the charging capabilities of your specific model.
Can You Charge A Solar Watch With Artificial Light?
Solar watches, despite the name, can capture a wide range of light other than sunshine. Although solar timepieces are most effectively charged using natural light, certain types of artificial illumination may be utilized to charge solar watches.
While it is not absorbed as efficiently or effectively as sunlight, bright artificial lights of high intensity can be captured by the solar cells and slowly stored by the battery. The light sensitivity of different watches and their ability to read artificial light will vary, but brighter lights that are close by are generally better.
Fluorescent light is an effective form of artificial light for charging a solar watch due to its high intensity. Some solar watches can be more sensitive to UV light than others, so it isn’t recommended to recharge a solar watch under prolonged periods of direct, high-intensity sunlight.
Despite being able to be powered by indoor or artificial lighting, it is an inefficient way to charge a solar watch. Solar watches respond better to natural, UV light.
Artificial light requires greater intensity and duration to excite the electrons in the solar panels of the watch, movement of electrons allows charge to flow and energy to be stored, This means that the watch charges more slowly when exposed to artificial light versus natural light.
Are Solar Watches Reliable?
Solar watches are extremely accurate when it comes to keeping the time correctly. Solar watches run continuously (unless deprived of light for long periods). This means that it never loses track of time, which happens when a normal watch’s battery dies or needs replacing.
Solar watches are generally hardy and extremely reliable, meaning that they are likely to run for years without stopping. The reliability of a solar watch is among its biggest selling points along with its long life, accuracy, and eco-friendly and easy use of solar charging. Because solar watches are always recharging and very rarely falter, they far outperform other watch types when it comes to their accuracy.
Solar watches are also extremely reliable due to their durability relative to the other watches. Because you don’t need to open the watch to change the battery, wind the watch up, or tinker with the inner mechanisms, the casing is much more solid and is made from heavy-duty materials like hardened crystal or titanium. If you want an accurate, durable, and reliable watch, then solar watches are for you.
Final Thoughts
Solar watches are a great choice for an eco-friendly and reliable watch. They can be powered by natural or artificial light, making them easy to charge anywhere. Solar watches are also very accurate and tough, meaning they will last for years without needing batteries replaced or other repairs. If you want an accurate, durable, and reliable watch that is also eco-friendly, solar watches are the perfect option!