About this replacement
Huawei Mate Xs / TAH-N29m — 3.85V Li-Polymer Replacement Battery (HB3246A1EEW)
This is a 3.85V, 2150mAh Li-Polymer cell replacing part number HB3246A1EEW in the Huawei Mate Xs foldable smartphone. It fits the TAH-N29m and TAH-AN00m variants. Dimensions are 98.30 × 45.00 × 3.00mm — measure your existing cell before ordering, as foldable housings leave no tolerance for a misfit pack.
- Mate Xs foldable platform fit: The TAH-N29m and TAH-AN00m share the same battery bay geometry and BMS handshake protocol. The HB3246A1EEW connector pinout carries both power and the authentication line the Huawei charge IC uses to validate the cell before enabling SuperCharge current.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Mate Xs unit. The BMS accepted the cell on first connection, charge current ramped correctly through the CC/CV stages, and voltage held within spec at 4.35V at top of charge.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve for the new cell before high-current SuperCharge pushes current into an uncalibrated coulomb counter.
Sudden shutdown at 20–30% on the Mate Xs after a cell swap
The Mate Xs runs a high-load display pipeline across its foldable panel — the large OLED draws a sharp current spike whenever the hinge flexes or the screen refreshes at full brightness. A new cell with an uncalibrated fuel gauge IC will hit a voltage cliff under that load before the percentage readout reaches zero. The phone interprets the voltage drop as a dead cell and shuts down. Run two full discharge-charge cycles without fast charging to let the coulomb counter re-anchor its state-of-charge curve to the new cell's actual capacity.
USB-PD or SuperCharge not accepted on the first cycle after replacement
Huawei's SuperCharge handshake requires the charge IC to authenticate the cell's BMS before stepping voltage above the standard 5V USB floor. On the first cycle with a new cell, the charge IC may stay at slow-charge current while it validates the BMS response. This is not a fault — it resolves after one complete charge to 100% via a standard 5V charger. If SuperCharge still does not engage on the second cycle, check that the connector is fully seated, as a partial connection breaks the authentication line and keeps the IC locked at low current.