HB386689ECW Huawei Honor Magic 2 Replacement Battery 3.85V 3400mAh

Huawei Honor Magic 2 — 3.85V Li-Polymer Replacement Battery (HB386689ECW)

This 3400mAh (13.09Wh) lithium-polymer cell replaces the factory battery in the Huawei Honor Magic 2, including TNY-AL00 and TNY-TL00 variants. It runs at 3.85V nominal and matches the original cell's physical footprint at 87.20 × 64.48 × 3.94mm. If your Magic 2 is shutting down unexpectedly, draining fast, or refusing to charge past a certain point, the original cell has likely degraded beyond recovery.

• TNY-AL00 and TNY-TL00 compatibility: Both TNY variants share the same battery bay geometry, connector pinout, and BMS handshake protocol. The HB386689ECW part number covers both — the regional suffix on the model number does not change the battery spec.
• Bench tested on actual hardware: We cycled this cell on a Magic 2 unit and confirmed the BMS accepted the new cell without triggering a charge fault. The protection circuit responded correctly to cutoff at both ends of the voltage window — no false over-voltage or under-voltage trips during our test cycles.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard speed. The fuel gauge IC in the Magic 2 is calibrated to the old cell's discharge curve — skipping this step causes the OS to report incorrect percentages until the coulomb counter resets against real cell behaviour.

Sudden shutdown at 20–30% on the replacement cell

This is the most misread symptom after a cell swap on the Magic 2. The phone shuts down not because the battery is empty, but because the cell voltage drops below the SoC floor the modem and display controller will tolerate under load. A fresh lithium-polymer cell has a steeper voltage cliff than a partially degraded one — the fuel gauge IC, still calibrated to the old cell, misreads this as 20–30% remaining. Run one full discharge cycle without fast charging. The coulomb counter will remap the voltage curve to the new cell's actual discharge profile and the shutdowns will stop.

USB fast charging not engaging after battery replacement

Huawei's proprietary fast charge protocol negotiates between the charger and the device's charge IC on first contact. After a cell swap, the charge IC sometimes defaults to a conservative 5V/1A profile until it completes one standard-rate cycle on the new cell. This is a protection behaviour — not a fault. Use the original Huawei charger, not a third-party USB-PD adapter, for the first full charge cycle. After that cycle completes, fast charging should re-engage at the expected voltage and current levels.