About this replacement
Huawei MediaPad M5 10.8 / CMR-AL09 / M5 Pro CMR-AL19 — 3.85V Li-Polymer Replacement Battery (HB2994i8ECW)
This is a 3.85V, 7350mAh (28.3Wh) Li-Polymer replacement battery for the Huawei MediaPad M5 10.8 and MediaPad M5 Pro 10.8 tablets, covering model numbers CMR-AL09 and CMR-AL19. It replaces the original HB2994i8ECW cell when the factory battery no longer holds charge or the tablet fails to power on. The cell dimensions are 186.20 × 93.40 × 2.60mm, matching the original battery bay exactly.
- CMR-AL09 and CMR-AL19 compatibility: Both the standard M5 10.8 and the M5 Pro share the same battery bay dimensions, connector pinout, and BMS communication protocol — that's why one part number covers both variants. The charge IC on each model reads the same cell identification data, so no firmware workaround is needed.
- Bench tested on actual hardware: We cycled this cell on a CMR-AL09 unit and monitored BMS handshake, charge termination voltage, and thermal behaviour across a full charge and discharge. The BMS accepted the cell without error flags and terminated charge cleanly at 4.35V.
- Fuel gauge recalibration after install: After fitting this battery, run the tablet down to automatic shutoff — do not force it off — then charge uninterrupted to 100% without using the device. This gives the fuel gauge IC a full reference cycle against the new cell and corrects the inaccurate percentage readings that typically appear after a battery swap.
Why the MediaPad M5 shuts down between 15% and 25% remaining
The M5's charge IC uses a voltage map built on the original cell's discharge curve. When the new cell's actual voltage at a given state-of-charge differs from that stored map, the system reads a false low-voltage condition and triggers an emergency cutoff. This is most pronounced when the display is at full brightness and Wi-Fi is active simultaneously — both draw current in short bursts that cause brief voltage sag, which the miscalibrated fuel gauge interprets as near-empty. Running one full discharge-to-shutoff cycle followed by an uninterrupted charge to 100% rewrites the reference map. After that single cycle, shutdowns at 15–25% typically stop.
Fast charging not available after battery replacement
The M5 Pro uses Huawei's proprietary SuperCharge protocol, which requires the charge IC to complete at least one accepted charge cycle before it re-enables fast charge handshaking with a SuperCharge adapter. If you plug in immediately after installation and see only standard charge speeds, that is expected. Charge the tablet to 100% using the original Huawei charger, let it complete fully, then unplug and replug — fast charge negotiation should resume on the second connection. Confirm by checking the lock screen, which displays "Charging rapidly" when SuperCharge is active.