If you want a smartwatch that can survive days or weeks away from a charger, the field is narrow and one brand dominates it: Garmin. The best smartwatches with solar charging today are the Garmin Instinct 2 Solar and Instinct 2X Solar (Garmin advertises effectively unlimited battery life in smartwatch mode under the right sun exposure), the Fenix 7 Solar series for feature-rich multisport use, and the Enduro 2 for the longest expedition-grade runtime. Solar doesn’t replace charging outright, but on these watches it can dramatically extend the time between plug-ins — which is exactly what off-grid users need.
[[AFFDISCLOSURE]]
- Garmin is essentially the only major brand offering true solar-charging smartwatches with published spec data
- Solar extends battery life but relies on strong, sustained sunlight — it is a supplement, not a substitute for charging
- Instinct 2 Solar targets everyday endurance; Fenix 7 Solar and Enduro 2 add maps, multisport tools and longer runtime
How solar charging on a smartwatch actually works
Solar smartwatches use a transparent photovoltaic layer built into the watch glass — Garmin calls its version Power Glass. Light passing through the display is partly harvested to trickle-charge the battery. It’s a supplement to normal charging, not a full replacement: the panels are small, and output depends heavily on light intensity, measured in lux.
Garmin’s runtime claims assume a specific reference condition — typically 50,000 lux (roughly bright, direct daylight) for a set number of hours per day. Indoor office lighting is often only a few hundred lux, so real-world gains vary widely with your environment, wrist position, and how long your sleeves cover the watch.
The best solar-charging smartwatches
Garmin Instinct 2 Solar / Instinct 2X Solar — best all-around off-grid pick
The Instinct 2 Solar is the model most closely associated with the “charge it once and forget it” reputation. Garmin lists it as offering unlimited battery life in smartwatch mode with adequate solar exposure, thanks to its power-efficient monochrome memory-in-pixel display. The larger Instinct 2X Solar adds a built-in LED flashlight and a bigger case and battery. Both are rugged (MIL-STD-810 tested), which suits hiking, hunting, and expedition use.
Garmin Fenix 7 Solar series — best premium multisport option
If you want full-color mapping, touchscreen navigation, and deep multisport features alongside solar, the Fenix 7 Solar, 7S Solar (smaller) and 7X Solar (largest) are the picks. The color display draws more power than the Instinct’s, so solar gains are more modest in relative terms — but the larger 7X Solar still posts very long runtimes.
Garmin Enduro 2 — longest runtime for ultra-endurance
The Enduro 2 is built for ultramarathoners and multi-day expeditions, pairing a large solar lens with a lightweight titanium build and Garmin’s longest GPS battery figures. It’s the choice when you need the most hours of active tracking, not just standby time.
Solar smartwatch comparison
Figures below are Garmin’s published manufacturer estimates. “With solar” numbers assume all-day wear with sufficient sunlight; your results will differ.
| Model | Smartwatch mode | With solar | Display | Best for |
|---|---|---|---|---|
| Instinct 2 Solar | ~28 days | Unlimited* | Monochrome MIP | Everyday off-grid |
| Instinct 2X Solar | ~40 days | Unlimited* | Monochrome MIP | Larger case + flashlight |
| Fenix 7X Solar | ~28 days | ~37 days | Color MIP + touch | Mapping & multisport |
| Enduro 2 | ~34 days | ~46 days | Color MIP + touch | Ultra-endurance |
*”Unlimited” applies in smartwatch mode with sustained sun exposure per Garmin’s reference conditions.
What to look for in a solar smartwatch
- Display type: Low-power monochrome memory-in-pixel screens (Instinct) benefit most from solar. Bright OLED and color displays consume more than a small panel can offset.
- Case size: Larger cases fit larger solar lenses and bigger batteries — part of why the 2X and 7X post higher numbers.
- Your climate: Solar shines (literally) for people who spend hours outdoors. Desk-bound users will see minimal benefit.
- GPS habits: Continuous GPS, maps, and music burn through charge far faster than solar can refill. Check the GPS-mode figures, not just standby.
- Durability & water resistance: Off-grid watches should be rugged and water-rated. See our guide to water-resistance ratings.
Do non-Garmin brands offer solar?
Not meaningfully, at least not as full smartwatches. Apple Watch, Samsung Galaxy Watch, and most fitness-focused wearables rely on conventional charging — and their bright color displays would overwhelm a small solar panel anyway. Some Casio G-Shock hybrids use solar assist, but they aren’t app-driven smartwatches in the same category. If solar charging is a hard requirement, Garmin is effectively your list. For a broader look at how the major brands stack up on runtime, see our battery life comparison.
Who should buy a solar smartwatch
Choose a solar Garmin if you hike, hunt, backpack, or travel where outlets are scarce, and you value multi-week standby over a bright touchscreen. If you mostly track daily activity in a city, a standard smartwatch will serve you just as well — the solar premium mainly pays off outdoors. Whichever you pick, learn to track workouts efficiently to preserve charge on long days.
Frequently asked questions
Can a solar smartwatch really run forever without charging?
Not literally. Garmin’s “unlimited” claim applies to low-power smartwatch mode with consistent, strong daily sunlight. Turn on continuous GPS, an always-on display, or music, and the watch will still need a cable eventually. Solar extends time between charges — it doesn’t eliminate charging.
How much sunlight does solar charging need?
Garmin’s estimates reference bright outdoor conditions around 50,000 lux. Ordinary indoor lighting is a fraction of that, so office and evening wear contribute very little. The more direct daylight your wrist gets, the more you’ll benefit.
Does solar charging shorten battery lifespan?
Solar trickle-charging is gentle and works within the watch’s normal charge management, so it isn’t known to harm the lithium battery. As with any wearable, long-term capacity naturally declines over years of charge cycles regardless of the charging method.
Do solar watches still support health tracking?
Yes. Garmin’s solar models include heart rate, SpO2, and sleep tracking, though enabling always-on sensors like pulse oximetry increases power draw and reduces the runtime solar can offset.