About this replacement
Huawei Watch GS Pro / Watch 4x / Watch 4s — 3.85V Li-Polymer Replacement Battery (HB672836EEW)
This is a 3.85V, 740mAh Li-Polymer cell (HB672836EEW) for the Huawei Watch GS Pro, Watch 4x, and Watch 4s. It replaces the original cell when capacity has faded or the watch no longer holds a charge. Dimensions are 34.00 × 26.60 × 6.50mm — measure your existing cell before fitting if you are unsure.
- Watch GS Pro, 4x, and 4s compatibility: All three models share the HB672836EEW cell format, the same 3.85V nominal rail, and a compatible BMS handshake — one cell covers the full group without connector or firmware conflict.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the GS Pro platform and confirmed the BMS accepted the new cell without triggering a protection cutoff or locking the fuel gauge at an incorrect reference point.
- Post-swap charge requirement: After fitting this cell, place the watch on its magnetic charger immediately and run it to 100% before first use. The fuel gauge IC on this platform cannot set an accurate reference point without one full charge cycle from near-zero — skip this and the percentage display will read incorrectly for days.
Why the Watch GS Pro reports 0% and shuts down straight after a cell swap
The GS Pro uses a coulomb-counting fuel gauge IC that tracks charge state relative to a stored reference. When you remove the old cell, that reference is lost. The IC has no way to estimate the new cell's state, so it defaults to zero and the watch shuts down before you can even navigate to the watch face. This is not a fault with the replacement cell. Put the watch on charge immediately after reassembly, let it reach 100%, and the gauge will write a new reference. The display will then read accurately on every subsequent cycle.
Battery draining to empty inside one day on the Watch GS Pro
The GS Pro's always-on display combined with continuous heart rate monitoring and active GPS sessions draws significantly more current than the watch's estimated multi-day figure assumes. If all three are running simultaneously, the 740mAh cell is under sustained load and will deplete faster than standby figures suggest. Check the watch settings and confirm GPS is set to on-demand rather than continuous, and that the always-on display timeout is active. Turning continuous HR monitoring to interval-based sampling rather than real-time will have the largest single impact on daily draw.