The Amazfit T-Rex Dual Solar is out Oct 29, 2026 (official) at a manufacturer's suggested retail price of ¥109,800. It's a buy if you want a watch with a bright screen and a light for traverses of 2 or 3 nights in huts. For a week without charging, the Garmin Enduro 4 fits better.
The Gear Nerd's Pick
While it's on your wrist, the solar panel on the back of this watch can't catch light, because the back sits against your skin. So I choose it with the time included when I take it off at the hut or campsite and set it back-up in the sun. The light-receiving area on the back is more than double the front's, and those moments off the wrist add to the battery.
Key points
- Up to 41 hours of high-accuracy GPS. At 10 hours of recording a day, 41 ÷ 10 gives 4 days. That's without counting on solar
- Solar adds 9 days on the front and 26 days on the back (against 25 days of ordinary use). The back is about 2.9 times as effective
- ¥28,200 price gap versus the Enduro 4. The Enduro 4 has 19 more hours of high-accuracy GPS
Is the T-Rex Dual Solar worth buying for hiking? Reading the "up to 180 days" claim
The most prominent claim in the announcement, "up to 180 days," is a power-saving mode that takes a GPS fix only once an hour, plus the back solar. It isn't a figure for recording a hike.
What you can rely on in the mountains is the other number: up to 41 hours of high-accuracy GPS. Since it isn't out yet, I judged it on that figure.
How I judged it
The first thing I looked at was high-accuracy GPS time without solar. 41 hours divided by 10 hours a day is 4 days. Then I lined it up against the Garmin Enduro 4, made for the same mountains. What gave me pause: its battery can't match the Enduro 4's. I still recommend it, because it costs ¥28,200 less and puts a bright screen and a light on the wrist. It suits people whose traverses are mostly up to 2 or 3 nights in huts.
Amazfit T-Rex Dual Solar
Pre-release: available from Oct 29When does the T-Rex Dual Solar come out? Price and numbers
| Item | Official listing |
|---|---|
| Release date / price | Oct 29, 2026 · ¥109,800 (pre-orders from Oct 16) |
| Weight and size | Watch 69g · 51.4mm diameter · 14.5mm thick |
| Display | 1.32-inch AMOLED · up to 3,000 nits · sapphire glass |
| Battery | Up to 25 days in ordinary use / 34 days with front solar / 51 days with back solar |
| GPS | Up to 41 hours in high-accuracy mode · dual-band · 6 satellite systems (including Michibiki/QZSS) |
| Durability | 10 ATM · 9 MIL-STD-810H test items · cold mode down to −30°C |
How much does the back solar help?
Against 25 days of ordinary use, front solar adds 34 − 25, or 9 days, and the back adds 51 − 25, or 26 days. 26 ÷ 9 means the back is about 2.9 times as effective as the front. The light-receiving area on the back is more than double the front's, and this is the newest part of the watch.
That said, 50,000 lux is a sunny day outdoors, and it doesn't reach in forest or on cloudy days. I treat solar as a bonus and plan the trip around 41 hours.
T-Rex Dual Solar vs T-Rex 3 Pro, with the Enduro 4 alongside
| Model | Battery capacity | High-accuracy GPS | Solar |
|---|---|---|---|
| T-Rex Dual Solar | 660mAh | Up to 41 hours | Front and back |
| T-Rex 3 Pro (48mm) | 700mAh | Up to 38 hours | None |
| Garmin Enduro 4 | Not published | About 60 hours | Front |
The gap with the T-Rex 3 Pro: 3 hours and solar
The battery capacity is down 40mAh, yet high-accuracy GPS gained 3 hours. Ordinary use is up to 25 days on both. The case grew from 48mm to 51.4mm and the band from 22mm to 26mm wide. That's the catch: it will feel big on a slim wrist.
Image: Rakuten Ichiba
Amazfit T-Rex 3 Pro (48mm)
Lowest price on Rakuten: ¥50,910 (as of 10/17). Prices vary by shop, up to ¥59,900, and change daily.
RecommendedSee it on RakutenVersus the Enduro 4: a trade between price and battery
Dividing high-accuracy GPS hours by price in units of ¥10,000, the T-Rex Dual Solar is 41 ÷ 10.98, about 3.7 hours, and the Enduro 4 is 60 ÷ 13.8, about 4.3 hours. The Enduro 4 is the better value on battery. Still, if you can recharge once every 4 days while staying in huts, the ¥28,200 difference can go to other gear.
Image: Rakuten Ichiba
Garmin Enduro 4
Pre-release: available from Oct 22The details of the Enduro 4 battery are in the Garmin Enduro 4 review, and how I think about the weight of a watch, camera and power is in how to choose a hiking GPS watch, and my pick. I wrote up Garmin's other new release in the Garmin fenix 9 Pro Dual Power review.
Things to watch
First is size. At 51.4mm and 69g, the band adds another 25.5g. If you have a slim wrist, the safe way is to try it on in a store before deciding.
Second is maps. Contour maps are downloaded and used on the watch. You can import GPX files made in YAMAP, but exporting from YAMAP is for Premium members only. A watch map is one tool for checking where you are, so carry a paper map and a smartphone separately.
Who is it for?
It fits people who can use 41 hours of GPS and a 25-day battery, anywhere from hut stays to traverses of several days.
For a week-long traverse without charging, the Enduro 4, at about 60 hours, is another way to choose. If you already own a T-Rex 3 Pro (48mm), what you gain is 3 hours of GPS and solar.
If you want a watch that needs no charging, there's also the Suunto Core 2 review.
FAQ
When does the T-Rex Dual Solar come out, and what does it cost?
Out Oct 29, 2026, with a manufacturer's suggested retail price of ¥109,800. Pre-orders opened on Oct 16.
How is the T-Rex Dual Solar different from the T-Rex 3 Pro?
Solar on both the back and the front, 3 more hours of high-accuracy GPS (41 vs 38 hours), and a bigger 51.4mm case. The maximum 25 days of ordinary use is the same.
How much does the T-Rex Dual Solar weigh?
The watch is 69g, and the black band is 25.5g.
