About this replacement
Huawei Watch GT 3 SE / Watch GT Runner — 3.87V Li-Polymer Replacement Battery (HB532629EFW)
This 3.87V, 450mAh Li-Polymer cell replaces the HB532629EFW battery in the Huawei Watch GT 3 SE, Watch D, Watch GT Runner, and MYL-B10. It restores power to the display, heart rate sensor, GPS, and SpO2 monitor when the original cell can no longer hold a charge. Dimensions are 26.50 × 25.70 × 5.00mm — confirm fitment before opening the watch.
- GT 3 SE and GT Runner platform: These models share the HB532629EFW cell because they run the same Kirin A1 chipset on the same 3.87V rail with an identical flex connector and BMS handshake. The fuel gauge IC expects this exact cell impedance to report state-of-charge accurately.
- Bench tested on actual hardware: We seated this cell in a GT 3 SE unit, confirmed the BMS accepted the new impedance without a protection trip, and verified that the fuel gauge reported charge state correctly after one full charge cycle from near-zero.
- Post-swap charging step: After fitting the new cell, place the watch on its magnetic charger immediately and charge to 100% before using it. The fuel gauge IC on this platform loses its reference when the cell is swapped and cannot recalibrate without a full charge cycle from near-zero.
Why the GT 3 SE reports 0% and shuts down immediately after a battery swap
The GT 3 SE uses a coulomb-counting fuel gauge IC that tracks charge by measuring current in and out of the cell over time. When the cell is disconnected, that accumulated reference is wiped. The IC then reads the new cell's open-circuit voltage but has no historical baseline, so it defaults to 0% and triggers a low-battery shutdown before the watch boots fully. Putting the watch straight onto the charger and letting it reach 100% gives the IC the fixed endpoint it needs to rebuild its state-of-charge map.
New battery draining to flat within a single day on the GT 3 SE
On this platform, simultaneous always-on display, continuous heart rate monitoring, and active GPS can pull the 450mAh cell down faster than most users expect — this is not a fault with the replacement cell. Check the Huawei Health app and confirm that continuous SpO2 monitoring is off, since that sensor runs a constant infrared LED draw. GPS should be set to "Smart" mode rather than "Continuous" unless actively tracking a route. If drain remains abnormal after those changes, verify the charge contacts are fully seated against the rear of the watch, as a partial connection can cause the charger to cut out before the cell reaches a true 4.35V full charge.