The word ‘rugged’ springs to mind when setting eyes on Matrix PowerWatch 2 ($199). The chunky 47mm frame comes across like it’d be insulted if you dared wear it in an office rather than on a hike in some far-flung forest. And in the latter use-case, PowerWatch 2 has your back – the always-on display can provide GPS and heart-rate read-outs, metrics syncing with HealthKit or Google Fit. The really clever bit, though, is how it charges, utilising ‘wasted’ energy from the sun and your own body heat. So although PowerWatch 2 might lack the grace of an Apple Watch and the app ecosystem of its many rivals, you might find it more reassuring to have a wearable on your wrist that only runs out of juice when you do.