About this replacement
Samsung Galaxy Watch 5 44mm — 3.88V Li-Polymer Replacement Battery (GH43-05114A)
This 3.88V, 380mAh Li-Polymer cell replaces the original battery in the Samsung Galaxy Watch 5 44mm. It fits SM-R910, SM-R915, and SM-R915U variants. The OEM part numbers GH43-05114A and EB-BR910ABY both cross to this cell.
- SM-R910 and SM-R915 series fitment: These variants share the same internal chassis, cell footprint, and BMS handshake protocol. The 25.30 x 23.30 x 5.50mm cell dimensions are consistent across the 44mm platform regardless of cellular or Wi-Fi-only configuration.
- Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the SM-R910 platform. The BMS accepted the cell without fault codes, and the fuel gauge IC registered correctly after a full charge cycle from near-zero.
- Post-swap charge cycle: After fitting this cell, place the watch on its magnetic charger immediately and bring it to 100% before use. The fuel gauge IC on the Watch 5 loses its reference point during cell removal and cannot calibrate state-of-charge accurately without a complete charge cycle from near-zero.
Why the Watch 5 fuel gauge reads incorrectly after a cell swap
The Galaxy Watch 5 uses a coulomb-counting fuel gauge IC that tracks charge by measuring current flow over time. When the cell is removed, that running count resets to zero or an undefined state. The IC then has no valid reference to calculate remaining capacity against. A full charge from near-zero gives the IC a known endpoint, letting it recalibrate and report accurate percentages again.
Watch not pairing to phone after battery replacement
Removing the battery cuts power to the BLE radio mid-session. The watch loses its active pairing session data held in volatile memory, and the Galaxy Wearable app on the phone still expects the old session to be active. The fix is to open the Galaxy Wearable app, remove the watch, and re-pair it from scratch. Do not attempt a Bluetooth toggle — a full re-pair through the app is required.