About this replacement
Huawei Mate S / CRR-L09 — 3.8V Li-Polymer Replacement Battery (HB436178EBW)
This is a 3.8V, 2600mAh Li-Polymer replacement battery for the Huawei Mate S smartphone, including variants sold under model numbers E2629, 2629, and CRR-L09. It replaces part number HB436178EBW and HB436178EBW+. Fit this cell when the original battery no longer holds charge or has swollen past the 4.42mm thickness threshold.
- Mate S model family: The E2629 and CRR-L09 variants share the same voltage rail, connector pinout, and BMS handshake protocol — one cell covers all of them without modifications or adapter cables.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Mate S unit. The BMS accepted the cell without rejection flags, charge IC stepped through CC-CV phases correctly, and the fuel gauge IC logged the new cell's discharge curve after one full cycle.
- First-cycle calibration on the Mate S: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes into an uncalibrated cell — preventing early percentage drift.
Sudden shutdown at 20–30% on a replacement cell in the Mate S
The Mate S fuel gauge IC retains the discharge curve from the old cell in non-volatile memory. When a new cell is installed, the IC maps real-time voltage against the old curve — and at 20–30% reported charge, the new cell's actual voltage may already be below the load threshold the modem and display draw during peak use. The phone cuts out because cell voltage collapses under load, not because the percentage is genuinely low. One full uninterrupted discharge-charge cycle rewrites the coulomb counter baseline and corrects this behaviour.
USB fast charge not activating on the first cycle after fitting this battery
On first connection after installation, the Mate S charge IC runs a brief handshake to confirm the BMS state before allowing high-current protocols. If the cell rested at a low state of charge during shipping or storage, the IC may default to trickle charge until cell voltage rises above 3.0V. At that point, it re-negotiates the fast charge protocol and current steps up automatically. Let the phone charge uninterrupted from a wall adapter — not a USB hub — on that first session.