Huawei HB446688ECW Ascend Mate 9 Pro Compatible Battery 3.82V 4000mAh

Huawei Ascend Mate 9 Pro — 3.82V Li-Polymer Replacement Battery (HB446688ECW)

This is a 3.82V, 4000mAh Li-Polymer replacement battery for the Huawei Ascend Mate 9 Pro and Mate 9 Pro Dual SIM smartphones. It carries OEM part number HB446688ECW and also fits the LON-AL00 variant and Mate 9 Porsche Design. It matches the original cell footprint at 88.45 × 66.14 × 3.86mm.

• Mate 9 Pro and LON-AL00 compatibility: These variants share the same battery bay geometry, connector pinout, and BMS handshake protocol. One cell fits all listed models because Huawei used a common power management IC across the Mate 9 Pro lineup regardless of regional variant or dual-SIM configuration.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on a Mate 9 Pro unit. The BMS accepted the cell without error flags, charge current stepped correctly through the CC/CV phases, and the fuel gauge IC registered capacity within expected tolerance at end of first cycle.
• First-cycle fast-charge protocol: On first use after installation, disable Huawei's SuperCharge for one complete discharge-charge cycle. The fuel gauge IC needs to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell — skipping this step can cause erratic percentage readings for several cycles.

Why the Mate 9 Pro reports wrong battery percentage after a cell swap

The Mate 9 Pro uses a coulomb-counter-based fuel gauge IC that builds its capacity model from the cell it was calibrated against — the original factory cell. When a new cell goes in, the IC still references the old discharge curve until it completes at least one full cycle. This mismatch causes the percentage to read high early in discharge and then drop sharply toward the end. One full discharge to automatic shutdown followed by a complete charge to 100% gives the IC enough data to rewrite its reference curve. After that first cycle, percentage accuracy tightens considerably.

Sudden shutdown at 20–30% on the Mate 9 Pro

This shutdown pattern is a voltage-cliff failure, not a capacity failure. Under high-load events — modem handoff, sustained screen brightness, or GPS — the cell voltage drops sharply below the BMS cutoff threshold even though the fuel gauge still shows charge remaining. On an aged original cell this happens because internal resistance has risen; on a fresh replacement cell it happens when the fuel gauge IC is still running the old discharge curve and calls shutdown too early. Run one full calibration cycle first. If shutdown persists after calibration, check that cell voltage at the cutoff point sits at or above 3.2V — anything lower points to a seating or contact issue at the connector.