Xiaomi’s supposed next-gen Watch has reared its head in a leak again. This one suggests that it might have the most screen-on time of its series to date.

It is now rumored to have a battery of no less than 930mAh, dwarfing the rated capacity of the Watch S4 at 486mAh, the Watch 2 Pro at 495mAh and even the “120-hour” OnePlus Watch 3 at 648mAh.

The vastly upgraded Watch is also thought to have faster charging, and might support LTE data too.

There is nothing very unusual about the latter – except that this one apparently has a dedicated embedded universal integrated circuit card (eUICC) for its standalone data, which might mean that it will be able to switch its service from carrier to carrier, in the way some older eSIM smartwatches cannot.

The wearable had been suspected of being a successor to the Watch 2 Pro – however, it runs HyperOS rather than the Wear OS of Xiaomi’s current flagship smartwatch, according to the latest leak.

Therefore, it just might be the next iteration of the Watch S line instead, even though the S4 has only debuted this year.

Either way, Xiaomi’s next Watch is now slated to launch alongside the 16 series of premium smartphones, the Pad 8 series of tablets and other assorted peripherals and/or smart-home gadgets in the third quarter of 2025.

The Watch S4: now available for $209.98 on Amazon

Deirdre O'DonnellDeirdre O Donnell – Senior Tech Writer – 8628 articles published on Notebookcheck since 2018

I became a professional writer and editor shortly after graduation. My degrees are in biomedical sciences; however, they led to some experience in the biotech area, which convinced me of its potential to revolutionize our health, environment and lives in general. This developed into an all-consuming interest in more aspects of tech over time: I can never write enough on the latest electronics, gadgets and innovations. My other interests include imaging, astronomy, and streaming all the things. Oh, and coffee.