If you're tired of your smartwatch running out of battery every day and the idea of a "solar-powered" smartwatch appeals to you, it's normal to wonder if Is solar charging in smartwatches really worth it, or is it just a fad?Models from Garmin, Suunto, Casio, or PowerWatch promise battery life that puts many classic wearables to shame, but the reality is a bit more nuanced.
In recent years, brands like Garmin have invested heavily in integration crystals with Power Glass™ and Power Sapphire™ technology capable of harnessing sunlight to extend battery life. Added to this are offerings like the Suunto Vertical Solar, Casio DW-H5600-1, and PowerWatch Series 2, which compete to see who can last the longest away from the charger. Let's take a closer look at how all this works, which models stand out, and, above all, Will you be able to forget about the charger on a daily basis, or will you still have to plug in the watch from time to time?.
How solar charging works in a modern smartwatch
The key to these clocks is not in large panels like those on a roof, but in a thin, semi-transparent layer of solar cells located between the screen and the watch crystalThis photovoltaic sheet covers practically the entire visible surface and is responsible for capturing light energy (mainly solar, but also to a lesser extent from indoors) and converting it into electricity.
In the case of Garmin, this layer combines Two distinct densities of solar traces: a denser one in the outer ring of the screen and a lighter one in the central areaThis combination allows the watch to collect energy without compromising screen readability or creating an extra layer of film that's noticeable to the naked eye. In fact, if no one tells you, you probably won't even realize it has a built-in solar component.
The technology is integrated into special crystals such as Power Glass™ (strengthened glass) and Power Sapphire™ (sapphire with solar component)Power Sapphire is especially interesting for outdoor watches like Fenix or some Instinct models, because Sapphire is the second hardest transparent material in existence, second only to diamond.This provides brutal protection against bumps and scratches, which is key if you spend a lot of time in the mountains.
This idea isn't new, but it has been perfected in a short time: Garmin first launched solar charging in the series fēnix 6 Back in 2019. Since then, they have been improving the efficiency of solar cells, energy management software and the balance between consumption and performance, until reaching models capable of offering autonomy measured in weeks or months.
In practice, what the clock does is use that solar energy as a complement to the internal batteryIt doesn't completely replace the charger, but it does greatly reduce how often you'll need to plug it in, especially if you spend a lot of time outdoors and don't take your watch off your wrist.
Real advantages of solar charging in smartwatches
The main benefit is obvious: more days of use per charge and, in certain modes, near-unlimited autonomyMany smartwatches with conventional batteries only last 1-3 days with normal use; models with solar charging from brands like Garmin or Suunto can last several weeks or even months, depending on the usage mode and how much light they receive.
In everyday life, this means that You won't have the constant feeling of "chasing power outlets"For someone coming from a watch that needs to be charged every night and is already slow due to age, the leap to a solar-powered watch like the Garmin Fenix 8 Solar or Instinct 3 Solar is huge. You can go on trips, do long hikes, train frequently, and still have more than enough battery life, especially if you make good use of solar charging and low-power modes.
Another strong point is that These models are usually associated with memory-in-pixel (MIP) displays, designed to be readable even in bright sunlight.Unlike AMOLED screens, which require a lot of backlighting, MIP displays consume very little power and look especially good outdoors, precisely where they can capture the most sunlight. It's a perfect combination for outdoor activities: long battery life and excellent visibility in direct sunlight.
In addition, many devices, such as certain Garmin watches and cycling computers (Edge 840 Solar, Edge 1040 Solar), They translate that solar contribution into concrete metricsIn cycling, for example, they show a "ride gain" or time gained thanks to solar charging, estimating around 20 extra minutes of battery life for every hour of pedaling in full sunThis makes it very clear that the solar component is not a marketing gimmick, but something measurable.
There is also a more "hidden" but very practical advantage: If a solar-powered watch runs out of battery completely, in many cases simply leaving it in full sunlight for a while will reactivate it.It's not magic (you're not going to charge it to 100% just with that), but it can get you out of a bind if you leave home with a dead watch and realize it when you're out on the mountain or traveling.
Limitations: Can the sun completely replace the charger?
Despite the promises of “infinite battery” on some posters, Solar charging for current smartwatches is intended as a complement, not as the primary source of energy.This is important: if you use GPS, notifications, music, and all the sensors a lot, you'll still need the charging cable, although much less than with a watch without a solar panel.
The efficiency of solar cells integrated into such a small crystal has its physical limits. To take full advantage of what today's technology offers, The watch needs to receive direct light, with the screen facing the sun. And without clothing or accessories covering it. Furthermore, weather conditions and the position of the sun (winter is not the same as summer, nor are very northern latitudes the same as sunnier areas) greatly affect performance.
Another key factor is how you use the watch. It's not the same as... basic clock mode With few active functions beyond continuous GPS tracking, route monitoring, active sensors, and constant notifications, manufacturers always provide various battery life figures: standard smartwatch mode, expedition mode, maximum power saving mode, high-precision GPS mode, etc. Even with solar charging, you'll still need to charge your watch periodically in the most demanding modes.
Therefore, Garmin itself makes it clear that Solar charging is intended to extend autonomy, not to replace traditional charging sources.In fact, when they talk about "unlimited battery life" in some modes, they do so under specific conditions (a certain number of hours of sunlight per day, limited activity, MIP screen, etc.). In real life, if you push the GPS or advanced features to the limit, that "unlimited" battery life isn't so unlimited anymore.
Even with these limitations, for someone who uses the watch regularly but not excessively, Solar charging makes the difference between charging every few days and forgetting about the charger for weeks.And that's where you really notice the leap compared to classic smartwatches with very nice screens but that are power-hungry and only last 1-2 days on battery.
Garmin solar smartwatches: Instinct, Fenix and company
Garmin is one of the brands that has invested the most in integrating solar charging technology in different ranges of watchesFrom relatively affordable models like the Instinct Solar to high-end models like the Fenix 7X Solar or Fenix 8 Solar, they all share some features: highly readable MIP displays in sunlight, long battery life, advanced health and fitness sensors, and Power Glass™ or Power Sapphire™ crystals.
The company has been extending solar charging to several product lines, including Instinct Solar, Instinct 2 Solar, Instinct 2X Solar, Instinct 3 Solar, Fenix 7X Solar, Fenix 8 Solar, and also cycling computers like the Edge 840 Solar and Edge 1040 SolarEven some golf-specific devices (like Approach solar-powered ones) take advantage of this technology to last for several rounds without needing to be recharged.
One rather useful detail is that Most of these watches display a solar intensity widget or indicator on the screen.This graph shows you how much light the panel is receiving and what level of energy input you're getting at any given moment. This way you can see if you're really taking advantage of the sun or if you're always in the shade and the solar charge is minimal.
In addition, many models incorporate specific energy-saving modes and usage profiles: Smartwatch mode, extreme power saving mode, expedition mode, training modes with different GPS levels… Combining these profiles with solar charging achieves the most spectacular autonomy, especially in the Instinct and Fenix ranges.
All of this is accompanied by a fairly comprehensive sensor package: heart rate, pulse oximetry, stress monitoring, sleep analysis, “Body Battery”, advanced performance metrics, safety features and, in the top models, navigation with integrated mapsIn other words, you not only gain battery life, but you also reach a very high level of sports and health performance.
Solar alternatives from other brands: Suunto, PowerWatch and Casio
Although Garmin dominates much of the conversation when it comes to solar watches, She is not alone in this raceThere are other manufacturers that have developed very interesting proposals, especially for users focused on mountaineering and long expeditions, or for those looking for something different from Garmin's usual aesthetic.
One of the most serious competitors is Suunto with its Vertical Solar modelThis watch is clearly designed for intense outdoor activities: it's water-resistant up to 100 meters, uses sapphire crystal, stainless steel, and titanium, and has been tested to military durability standards. Its full-color display offers highly detailed maps.
The maps on the Suunto Vertical are one of its distinguishing features: They include contour lines, rivers, roads, and different visual styles.In addition to being usable offline and free of charge, it includes safety features such as weather forecast, barometer, altimeter, and storm alarm, along with navigation to points of interest and routes.
Regarding battery life, Suunto boasts Up to 60 days of autonomy in daily mode thanks to the combination of internal battery and solar chargingand around 85 hours of exercise tracking with the most accurate GPS setting. For trekking, trail running, or long-distance runners, this is a very compelling argument.
Another interesting proposal is PowerWatch Series 2, which combines solar energy with body temperature monitoringThis watch is capable of converting both light and body heat into electricity, using technology similar to that employed in some NASA projects. In theory, this allows it to operate without traditional charging under optimal conditions.
The PowerWatch doesn't fall short in basic functions: It integrates GPS, heart rate measurement, sleep analysis, calorie counting, and activity tracking.It is made with sapphire crystal and an aircraft-grade aluminum alloy, giving it an interesting combination of lightness and strength.
For those who prefer something with a more classic aesthetic, The Casio DW-H5600-1 offers a retro look with modern technology and solar charging.Shockproof and water-resistant up to 20 bar, this model incorporates activity modes such as running, walking, interval and strength training, as well as real-time measurements of cardiovascular effort and the use of different energy sources.
The Casio's battery life is also surprising: More than 11 months in power saving mode, about a month in normal use without saving, and about 35 hours with continuous active heart rate measurementIt doesn't go to the extremes of some Garmin or Suunto models in terms of advanced features, but it's very competent as a robust sports watch with good training and sleep metrics, as well as breathing exercises and blood oxygen measurement.
Can I forget about the charger if I wear a solar watch every day?
The big question for many users coming from older watches or watches with short battery life is whether We've reached the point where simply wearing a solar watch daily means you never have to plug it in.The honest answer is that, as of today, it depends a lot on the model, how you use it, and the amount of light it receives.
In the case of watches like Garmin Instinct 3 Solar or Instinct 2X SolarWith its highly efficient MIP display and advanced power-saving modes, it's quite possible to achieve the "forget about the charger" mentality if your usage is moderate: notifications, some exercise, minimal continuous GPS, and plenty of sunlight each day. In fact, the watch itself can display the infinity symbol when it detects that solar charging is offsetting the power consumption.
With more powerful models and more features, such as Garmin Fenix 8 Solar or Suunto Vertical SolarBattery life remains spectacular, but you're more likely to end up using multiband GPS, maps, advanced metrics, and other battery-guzzling extras. In these cases, solar charging greatly extends the days between charges, but you'll rarely be completely free of the power outlet if you use everything it offers.
Furthermore, not everyone lives or trains outdoors in optimal conditions. If you spend most of your time indoors, in an office, wearing long sleeves, or in very cloudy weather, the amount of sunlight you get is significantly reduced.The watch will still have good autonomy thanks to its large battery and efficient screen, but the "solar" aspect will be much less prominent.
Even so, compared to a conventional smartwatch that needs to be charged every night or every other day, The leap to a well-optimized sundial is often a huge leap.This is especially interesting if you're coming from an older model that's already slow and runs out of battery every day: in that case, switching to a Garmin Instinct, Fenix Solar, or Suunto Vertical means moving to another league of comfort and autonomy.
To put it simply: Today, solar charging doesn't completely eliminate the charger, but it does greatly reduce dependence on it.And for many users, that's reason enough to opt for one of these watches instead of sticking with "power-guzzling" models that drain their battery in no time.
Looking at everything these devices have to offer —from Weeks or months of potential autonomy, extreme resistance, maps, advanced sports and health metrics, and the peace of mind of knowing that the sun always lends a hand when the battery is low.—, the truth is that solar charging in smartwatches has ceased to be a simple marketing claim and has become a very solid argument for those who value autonomy and outdoor life, especially if you come from a smartwatch that has you enslaved to the charger.
