T-Rex Dual Solar solar panels front and back on an AMOLED watch

What is new about the T-Rex Dual Solar?

Amazfit launched the T-Rex Dual Solar on 22 September 2026 and describes it as the first AMOLED smartwatch with solar charging on two sides. Solar sports watches have usually paired a solar layer with a dimmer memory-in-pixel or transflective screen. Here, one solar surface sits in the 1.32-inch AMOLED display and a second, which Amazfit says has more than twice the active charging area, is built into a glass-ceramic case back. A Solar Priority Mode drops the watch into an ultra-low-power state so it can soak up as much light as possible when it is off the wrist, and Bike Magazin reports that Amazfit includes a strap so the watch can be fixed to the outside of a rucksack with its back facing the sun.

How long does the battery last?

Amazfit quotes up to 25 days of typical use from the 660 mAh battery with no help from the sun. With three hours a day of front-panel exposure at 50,000 lux, that rises to 34 days, and Amazfit's figure using the rear panel under the same conditions is up to 51 days. In its most accurate GPS mode, Amazfit quotes up to 41 hours. For context, 50,000 lux is bright, direct sunlight. A grey British winter will not get close, so the 25-day figure is the more useful number for planning. Treat the solar as a top-up and an emergency backstop: Amazfit's own pitch is that a flat watch can be revived with sunlight to get maps and route information back.

How big is it, and how will it wear?

This is a big watch. Amazfit lists a 51.4 mm case that is 14.5 mm thick, and Gadgets & Wearables puts it at 16.9 mm including the heart rate sensor, with the body alone weighing 69 g before the strap. Amazfit does not publish a lug to lug figure. On wrists under about 17 cm it will overhang the edges, and it will not slide under a shirt cuff. The middle frame is fibre-reinforced polymer rather than metal, which keeps the weight below what an all-titanium case of this size would be.

How well is it built?

The bezel and buttons are Grade 5 titanium, the screen sits under sapphire crystal, and the watch is rated 10 ATM with support for recreational diving to 50 metres. Bike Magazin reports an operating range down to -30°C, and Amazfit adds a Low Temperature Mode to keep essential functions running in the cold. There is a built-in torch with white and red modes, the red setting helping to preserve night vision. The AMOLED screen peaks at a quoted 3,000 nits.

What does it do for navigation and training?

Full-colour maps come preloaded, with downloadable contour and ski layers, intelligent route planning, turn-by-turn navigation, waypoint navigation and points of interest, plus LiveShare for sending your live location, heading and activity data to friends or family. Gadgets & Wearables reports dual-band positioning across six satellite systems. Training, recovery and outdoor data sync to the free Zepp app with no subscription. For daily use there is Bluetooth calling, Zepp Flow voice control, offline music and, on the European version, NFC payments.

Is it good value against its rivals?

At a £649.90 RRP it sits £100 above Amazfit's own T-Rex Ultra 2, which launched at £549.90 with a larger 1.5-inch screen but no solar charging. Suunto's Vertical 2 costs £529 in stainless steel and also brings an AMOLED screen, a torch and free offline maps, again without solar. So the Dual Solar's premium buys the solar backstop and the titanium and sapphire specification rather than a longer list of features.

What is the catch?

The rear panel, which does most of the solar work, only charges when the watch is off your wrist, so on an ordinary day any extra endurance comes from the smaller front panel alone. Add the 51.4 mm case and 69 g body and this is a specialist expedition watch rather than an everyday one. It is also too new for meaningful owner feedback, so how well the solar surfaces and the glass-ceramic back hold up over years of use is not yet known.

“The back panel does the heavy lifting, but only when the watch is off your wrist.”