Instinct is a GPS smartwatch that resists conventions, works in extreme conditions and works longer. By harnessing the power of the Sun, you get a battery with a completely new level of life. Garmin Instinct 2 Solar

Underneath the rugged exterior is Garmin’s smartwatch tech, featuring market-leading sport, health and location-tracking. It has smartphone connectivity for notifications, alerts and syncing your data via the Connect app on an Android or iPhone.

It is very similar to many other Garmin sport watches, but the big differentiator for Instinct 2S is its solar-powered battery. It promises unlimited battery life and you never have to recharge your watch again. In the real world, of clouds and rain and stuck at an office desk, we think it probably means 10-30 days without a recharge. That is jolly good, but not quite unlimited.

The standard 45mm model without solar will last up to 28 days used as a general smartwatch, which is 10 days longer than the already impressive Fenix 7 and about 14 times longer than an Apple Watch.

The solar version, which charges using a transparent “power glass” covering the screen and panels around the edge of the display, promises to keep the battery topped up for essentially unlimited battery life as long as you spend at least three hours in direct sunlight (50,000 lux of light).

For mainly indoor usage during winter without much in the way of solar charging, the watch lasted about 15 days between charges, including five hours of workout-tracking. I wore it 24 hours a day with message alerts, heart rate, stress, calories, general activity and health monitoring, plus sleep and blood oxygen (SpO2) tracking overnight. Turning off the Sp02 sensor added days to the life as did limiting workouts. The solar charging would add at least 24 hours battery for each sunny spring day spent outside, too.

The watch tracks a vast number of activities including various forms of running, walking, cycling, swimming, strength, cardio, Hiit and more exotic ones such as paddle boarding, hunting, fishing, backcountry skiing and bouldering.

Some activities are restricted to special versions of the watch, such as the jumpmaster mode for skydiving being only available on the “tactical edition”, surfing and tide information on the “surf edition” and the truck-driver tools on the “dēzl edition” to plan breaks and workouts. Only the solar models have Garmin Pay for contactless payments too, which supports few UK banks but is useful in emergencies when out on excursions without a credit card or phone.

On the health front, it has Garmin’s excellent body battery, which makes it easy to understand the impact of sleep, activity and rest on your day, plus stress tracking, abnormal heart rate alerts, daily workout suggestions, Vo2 Max fitness measurement and recovery estimation after exercise and many other features.

All the activity and health information the watch collects is sent via Bluetooth to the excellent Garmin Connect app on your phone, within which you can pore over mountains of data, graphs and insights. Plus you can connect it straight to social networks such as Strava. Garmin Instinct 2 Solar

At €340 (£299.99/$349.99/A$549) retail, this is a premium device, entering Apple Watch territory.