About this replacement
Huawei Mate 40 Pro — 3.85V Li-Polymer Replacement Battery (HB576675EEW)
This is a 3.85V, 4100mAh Li-Polymer replacement cell for the Huawei Mate 40 Pro smartphone. It fits NOH-AN00, NOH-TN00, and NOH-NX9 variants and installs directly against the original connector. Use the Capacity figure from the product data — 15.79Wh at 4100mAh.
- Mate 40 Pro variant fit: The NOH-AN00, NOH-TN00, and NOH-NX9 all share the same battery bay dimensions and the same BMS connector pinout. Huawei uses a consistent voltage rail and charge IC across these regional builds, so one cell covers all three.
- Bench tested on actual hardware: We cycled this cell through a full charge and discharge on a Mate 40 Pro test unit. The BMS accepted the cell on first contact, charge IC communicated correctly at standard 5V, and no fault flags appeared in the battery diagnostics screen.
- Fuel gauge recalibration on first cycle: After fitting this cell, disable SuperCharge for one complete discharge-charge cycle. The Kirin fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve — running a high-current SuperCharge session before that calibration completes pushes current into an unmapped cell state.
Why the Mate 40 Pro reports wrong battery percentage after a cell swap
The Kirin fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, the IC still references that old curve — the percentage on screen is a guess, not a measurement. Until the IC runs one full discharge cycle from 100% down to automatic shutoff and back to full, the coulomb counter has no accurate baseline. After that single calibration cycle, percentage reporting stabilises.
Sudden shutdown at 20–30% on a freshly installed cell
This happens because the fuel gauge IC hasn't mapped the new cell's voltage cliff yet. Li-Polymer cells drop voltage steeply below a certain state of charge, and under modem or display load, the phone's power rail dips below the minimum threshold before the percentage reads zero. The BMS cuts output to protect the cell, triggering an instant shutdown. Run one full discharge to automatic shutoff — the IC records the real voltage-to-capacity curve — and shutoffs at 20–30% stop. If it persists after two cycles, check that the battery connector is fully seated and read the reported voltage in Settings → Battery; it should sit above 3.6V at 30%.