Charging up a smartwatch every night is a pain in the ass. But what if you only needed to charge it once every 21 days? Enter the 46mm Xiaomi Watch S5.
Xiaomi first released the Watch S5 in China back in March, but the company launched it internationally this week, with global availability starting in late May and early June depending on the region. While the Watch S5 hasn’t been announced for the U.S., the European pricing (€179.99 or €199.99 depending on the color and strap style) gives us an idea of what to expect should you want to import one. You’re looking at somewhere around $210 to $233.
How exactly does Xiaomi’s Watch S5 get up to 21 hours of battery life when competitors like the Apple Watch Series 11 ($400) and Samsung’s Galaxy Watch 8 ($350) can only muster around a day? There’s always a big asterisk next to battery life, but in this case, it seems pretty reasonable.
Light use of the Watch S5 allows the 815mAh battery to last up to 21 days. Xiaomi defines light use as receiving up to 100 messages per day with up to six daily incoming call alerts, three alarms per day, 30 minutes of Bluetooth calls per week, 30 minutes of music playback per week, and 90 minutes of exercise recording. Normal use will drop the battery life down to 14 days and using the always-on display will reduce it to about 9 days.

Other smartwatches that offer days of battery life don’t seem to come close to the Watch S5, either. The OnePlus Watch 3 ($350) and Amazfit Active 3 Premium ($170) provide around 3 days and up to 12 days, respectively. If you want truly “unlimited” battery life, you’ll need to consider a solar-powered watch like the Garmin Instinct series (starting at $300).
Other than its long battery life, the rest of the Watch S5 looks solid. Highlights include a 5-system dual-band GNSS (Global Navigation Satellite System), over 150 sport modes, heart rate monitoring, sleep tracking, and an enhanced cycling mode that turns your phone into a bike computer.
Of course, there are some features the Xiaomi Watch S5 lacks compared to its flagship competition, like an EKG sensor and depth gauge functionality. However, the Watch S5 includes professional skiing and cycling modes among its more than 150 sports.
The Watch S5 works best with a Xiaomi phone for shared ecosystem quality-of-life features, but it can connect to any smartphone via the Mi Fitness app for deeper sport mode tracking and health data storage.
As with all Xiaomi product launches, the main downside is that the company isn’t officially selling the Watch S5 in the U.S. Third-party sellers might stock it, but you may end up paying more than international MSRPs.