id="cnetReview" section="rvwBody" data-component="indepthReview"> It's handy to never need a watch charger.

Smartwatches are frustrating for many reasons, but the need to constantly recharge them is the worst. Some watches are finding ways to last more than a week, such as the Amazfit Bip. But what about lasting forever?

The Matrix Powerwatch X is a watch that's powered entirely by body heat. Thermal gradients, to be precise. The watch uses the difference between skin temperature and the outside air to generate a current that activates and charges everything. Sound weird? It is. Maybe it's the future of a world of wearables where everything is body-powered. Like... oh, yeah, that's why the company is called Matrix Industries.

I first met with Matrix Industries a couple of years ago. Its first product, the Matrix Powerwatch, debuted in 2017. The Matrix Powerwatch X is a more advanced watch, with step counting, sleep tracking and buzzing notifications.

<b>I'd love a watch to