About this replacement
Motorola Moto M / XT1663 — 3.85V Li-Polymer Replacement Battery (BL265)
This is a 3.85V, 3000mAh (11.55Wh) Li-Polymer replacement battery for the Motorola Moto M, Moto M Dual SIM, Moto M Dual SIM TD-LTE, and XT1663. It replaces OEM part number BL265 when the original cell has degraded, fails to hold charge, or causes unexpected shutdowns. Dimensions are 77.25 × 63.70 × 3.50 mm — match these before installation if you are unsure of your variant.
- Moto M variant compatibility: The XT1663 platform and its Dual SIM TD-LTE sibling share the same 3.85V rail, BL265 connector pinout, and BMS handshake protocol — one cell fits all listed variants without modification.
- Bench tested on actual hardware: We ran this cell on the XT1663 board and confirmed the BMS accepted the new cell on first connection — charge IC engaged correctly, protection thresholds tripped as expected under load, and no false over-voltage flags appeared.
- First-cycle fuel gauge recalibration: After installation, disable fast charging and run one full discharge-charge cycle at standard rate. The fuel gauge IC is calibrated to the old cell's discharge curve — one slow cycle lets it map the new cell before high-current charging begins.
Why the Moto M reports wrong battery percentage after a cell swap
The Moto M uses a coulomb counter inside the fuel gauge IC to estimate charge state. That counter was trained on the original cell's capacity and internal resistance profile. When a new cell goes in, the IC still references the old curve, so the percentage display drifts — sometimes reading 20% while the phone still has significant charge remaining, or jumping erratically between readings. One complete slow discharge down to automatic shutdown, followed by a full charge at standard rate, forces the IC to re-anchor its reference points to the new cell.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage cliff, not a capacity problem. Under peak load — modem transmit bursts or screen-on events — the cell voltage drops sharply below the BMS cutoff threshold before the fuel gauge registers low charge. It happens most often on the first few cycles before the fuel gauge IC has recalibrated. Run two full slow discharge-charge cycles and check whether shutdowns persist. If the phone still cuts out, measure resting cell voltage immediately after shutdown — a reading below 3.4V under no load confirms a cell fault rather than a calibration issue.