About this replacement
Amazfit GTR 3 / GTR 3 Pro — 3.87V Li-Polymer Replacement Battery (PL582624)
This 3.87V, 440mAh lithium-polymer cell replaces the original PL582624 battery in the Amazfit GTR 3 and GTR 3 Pro smartwatches (models A2040 and A2039). It restores power to the display, processor, heart rate sensor, GPS, and Bluetooth modules. Fit the new cell when the original no longer holds charge through a full day or swells inside the case.
- GTR 3 and GTR 3 Pro compatibility: Both watches share the same cell footprint, connector pitch, and BMS handshake protocol. The 23.30 × 25.30 × 5.70mm dimensions match the cavity in both A2040 and A2039 chassis without modification.
- Bench tested on actual hardware: We cycled this cell through the GTR 3 charge controller and confirmed the BMS accepted the cell, balanced correctly, and reported accurate state-of-charge to the firmware without error flags.
- Post-swap charge requirement: After fitting this cell, place the watch on its magnetic charger immediately and charge to 100% before first use. The fuel gauge IC on the GTR 3 platform cannot calibrate its reference point without a full charge cycle from near-zero following a cell swap.
Why the GTR 3 reports 0% and shuts down immediately after a battery swap
The GTR 3 uses a coulomb-counting fuel gauge IC that tracks charge state relative to a stored reference. When the cell is disconnected, that reference is lost. The IC sees an uncalibrated cell and defaults to 0%, triggering an immediate low-battery shutdown even if the new cell has a partial charge. This is not a fault with the replacement cell. Charge the watch to 100% from this state and the IC resets its reference correctly.
Watch not pairing with the Zepp app after battery replacement
Removing the battery cuts power to the BLE stack entirely, which drops the active pairing session stored on the watch. The phone retains the old session record, but the watch starts fresh with no matching bond key. Go to your phone's Bluetooth settings, forget the GTR 3, then re-pair through the Zepp app from scratch. Do not attempt to reconnect from the Bluetooth menu alone — the Zepp app handshake is required to restore full data sync.