As for supposedly confirmed details, the Mi Band 4 reportedly features Bluetooth 5.0. The device also comes with an improved “Heart Rate Monitoring” system and two models: XMSH08HM and XMSH07HM. The former model supposedly includes NFC, while the latter model doesn’t include NFC.
Sources claim the battery will now be 135 mAh, which would be an improvement of over 20% compared to the Mi Band 3 . With the screen going full color, it’s bound to consume more power so slightly more juice is needed if Xiaomi wants to keep the 20-day battery life.
Finally, the NFC version reportedly costs 499 yuan (~$72). That’s compared to the standard version, which might cost between 200 and 300 yuan (~$28-$43).
Xiaomi’s Mi Band has been one of the most successful fitness bands of all time. According to an IDC report, Xiaomi took the second spot in the global wearables market during the Q1 2019 period.