About this replacement
Asus A46 / K56 Ultrabook Series — 14.4V Li-ion Replacement Battery (A31-K56 / A32-K56)
This 14.4V Li-ion battery replaces the original cell in the Asus A46, A56, K46, and K56 Ultrabook series. It carries a capacity of 2200mAh (31.68Wh) and matches the OEM part numbers A31-K56, A32-K56, A41-K56, and A42-K56. Connector pinout and BMS communication protocol match the original specification.
- A46 / A56 / K46 / K56 platform fit: These four Ultrabook lines share the same battery bay dimensions, 14.4V rail, and multi-pin BMS handshake connector. One cell fits all four because Asus used a common power board across this chassis generation.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a K56 unit. The BMS communicated charge state correctly to the EC, held cutoff voltage within spec, and showed no thermal anomalies during the charge phase.
- Post-install calibration on the K56 EC: After fitting this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after swapping cells on this platform.
BIOS reporting poor battery health immediately after fitting a new cell
The Asus K56 EC reads health data from EEPROM stored on the outgoing cell. When a new cell goes in, that EEPROM data is blank or mismatched, so the BIOS flags poor health before any charge cycle runs. This is not a fault with the replacement cell — it is a firmware artefact. Run one full discharge to hibernate-cutoff, then a full uninterrupted charge to 100%. After that learn cycle completes, the EC writes fresh calibration data and the health warning clears.
Laptop shuts down hard at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The displayed percentage no longer matches the real cell voltage, so the system hits the low-voltage cutoff while the gauge still shows reserve capacity. It is not a defective cell — it is a calibration lag. Force two or three complete discharge-to-hibernate and full-charge cycles back-to-back, and the gauge will track accurately. After the third cycle, the shutdown point should align with a displayed level below 5%.