A little prying frees the battery easily. It’s great to see this common repair got prioritized, with a simple modular connector—no soldering required.

The battery is a 1.62 Wh (420 mAh at 3.85 V) Li-ion block which charges wirelessly.

Xiaomi claims that this little cell powers the watch for 16 days straight, or 50 hours during sports. Compare to: Apple Watch Series 6 (44 mm): 1.17 Wh, Samsung Galaxy Watch 3: 1.3 Wh, Huawei Watch GT: 1.6 Wh

In addition to the battery, the bottom part of the watch case bears a cable assembly with a tiny vibration motor, the heart rate and SpO2 sensor array, a barometric sensor, and a MEMS microphone.

Removing the cable assembly requires cutting through some plastic rivets—not a reversible or repair-friendly process. Afterward, your only reassembly option is to glue the cable down. Better hope nothing on there breaks.

Hiding behind the sensor board and peeking through the metal shield is a Texas Instruments AFE44l30 Biosensor Analog Front End module.