About this replacement
Huawei Magic GT / TLS-B19 — 3.8V Li-Polymer Replacement Battery (HB302527ECW)
This is a 3.8V, 170mAh lithium-polymer cell that replaces the original HB302527ECW in the Huawei Magic GT (TLS-B19) smartwatch. It restores power to the display, heart rate sensor, and Bluetooth radio when the original cell has degraded or failed to hold charge. Dimensions are 27.32 x 22.60 x 3.34mm — verify clearance before fitting.
- Magic GT / TLS-B19 platform fit: Both model designations share the same case geometry, connector pinout, and BMS handshake protocol. The HB302527ECW part number covers the full production run of this watch, so one cell fits both variants without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Magic GT unit. The fuel gauge IC accepted the new cell without fault codes, and the BMS completed charge termination cleanly at 4.35V.
- Post-swap charge cycle — Magic GT specific: After fitting, place the watch on its magnetic charger immediately and let it reach 100% before first use. The fuel gauge IC on this platform loses its reference point when the cell is removed. Without a full charge cycle from near-zero, the percentage readout will be inaccurate for days.
Why the Magic GT reads 0% immediately after a battery swap
The Magic GT uses a coulomb-counting fuel gauge IC that tracks charge state relative to a stored reference. When the cell is disconnected, that reference resets to zero. The watch has no way to know the new cell's actual state of charge, so it defaults to 0% or shuts down entirely. Place the watch on charge immediately after reassembly and let it complete a full charge to 100% — this re-establishes the gauge's baseline and restores accurate percentage reporting.
Charge contacts not making after reassembly
The Magic GT charges through magnetic pogo contacts on the case back. If the back panel shifts slightly during reassembly, the contact pads can misalign by as little as 0.5mm — enough to prevent charging. If the charger LED does not illuminate within 30 seconds of docking, remove the watch, inspect the case back alignment, and re-seat the rear cover. Clean the pogo pins with a dry cloth before retrying, then confirm the charger registers a connection before leaving the watch unattended.