Chris Townsend reviews a simple but innovative outdoor watch powered by body heat.

This review is part of our smartwatches gear guide, and was first published in the January 2019 issue of The Great Outdoors.

Quality and comfort

The Powerwatch X is waterproof and shockproof. On a few trips in the Cairngorms in stormy and cold weather it was fine. It’s a big watch but only weighs 85 grams. The watch strap is silicone rubber. I find it comfortable.

Ease of use

It is easy to use – mainly because there are very few functions (no GPS). It only takes a few minutes to run through the options.

Customisation options

To operate the watch, the Matrix app must be downloaded to your smartphone, purely for setup. But if you want to store info for more than a week you must keep watch and smartphone paired as it is downloaded to the latter. You can receive notifications of calls or messages on the phone (but you can’t read or reply to them on the watch).


The step counter/distance measure is fairly accurate.


If you want a watch with GPS, mapping, compass, altimeter/ barometer and more then this isn’t the one to choose. However if you want a watch that never needs charging and that gives you some distance/fitness data then the Powerwatch X is excellent. I think it’s ideal for long-distance walks because of this. The other features are all easier to use on smartphones anyway.

The technology in this watch is fascinating, and I hope it can be developed to allow more features. The Powerwatch has a thermoelectric generator that senses body heat and converts it to energy that charges a small internal battery. It needs to be firmly in touch with the skin to do this. You can see how much power is being ‘harvested’ by a display with bars that rise and fall in number depending on how much heat you provide. As it’s the temperature differential between your skin and the air that provides the energy, the watch will charge more quickly when you’re exercising and in cooler air. Above 32°C the watch cannot charge the battery. It will still work for up to a year though.