The lineup includes two new additions to Garmin's extra-tough Instinct range, which first launched in 2018. The Instinct Solar Surf Edition, as the name implies, is built for water sports, and offers tidal data and a dedicated surfing mode.
The Instinct Solar Tactical Edition, meanwhile, can keep going for up to 24 days indoors, and up to 50 days with sufficient exposure to sunlight – or indefinitely in power saver mode.
The Fenix series has also received two new additions. In March this year, Garmin launched the Fenix 6 X Pro Solar – a new flagship watch that built on the already impressive specs of the Fenix 6 Pro, with solar charging or improved battery life. Garmin has now followed this up with two more modestly specced models, making super-long battery life accessible to those on a slightly lower budget.
The Fenix 6 Pro Solar and Fenix 6S Pro Solar both feature dedicated modes for surfing, mountain biking and indoor climbing (in addition to the usual running, swimming and road cycling options), plus sleep monitoring, Garmin Pay, on-device music storage, and maps of golf courses and ski runs around the world.
The main difference between the two is battery life. The Pro S Solar can keep running in smartwatch mode (ie without GPS) for nine days indoors between charges, and up to 10.5 days with sufficient solar exposure. The Pro Solar, meanwhile, will last up to 14 days indoors, or up to 16 days with solar top-ups.
Finally, there's the Tactix Delta Solar Edition – a rugged watch built to military specifications. Its standout features include a stealth mode that toggles off location sharing and all wireless connectivity, plus a kill switch that wipes user memory. It's built from steel and tactical nylon with reinforced stitching, and can keep you sneaking for up to 21 days indoors, or 24 days outside in battery saver mode.
A typical sports watch might last seven days between charges (or less if you're using GPS to track runs), but Garmin's Power Glass makes a huge difference by providing regular top-ups with exposure to sunlight.
However, it's worth noting that while the Power Glass used in all of these wearables is scratch-resistant, it's not quite as tough as a sapphire crystal lens. It will charge best when the watch's face is directed towards the sun, and Garmin advises against using any kind of screen protector, as this may reduce the amount of light hitting the glass.
Garmin's previous solar watches have all been top-end devices with price tags to match, so it's great to see that Garmin is expanding the technology to other, more modestly priced fitness trackers.
Perhaps devices in the Forerunner line might be next to receive a solar upgrade, and the tech may even come as standard in forthcoming devices like the Garmin Fenix 7. We'll let you know as soon as we know more.
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Cat is the editor of TechRadar's sister site Advnture. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better)