About this replacement
Asus K45D / K45DE / K45DR Series — 10.8V Li-ion Replacement Battery (A32-K55)
This is a 10.8V, 4400mAh (47.52Wh) Li-ion replacement battery for the Asus K45D and related K-series notebooks. It fits the K45D, K45DE, K45DR, and K45N, along with over 100 additional Asus K-series models that share the A32-K55 platform. OEM part numbers covered include A32-K55, A33-K55, A41-K55, A32-K55X, 0B110-00050400, and 0B110-00050600.
- K45 and K55 platform compatibility: These models share the same battery bay dimensions, 10.8V supply rail, and BMS handshake protocol. A single cell covers all variants without physical or firmware conflicts.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on K-series hardware. The BMS communicated correctly with the BIOS, reported accurate state-of-charge, and held voltage through load transitions without triggering a protection cutoff.
- Post-install calibration for K-series BIOS: After fitting this cell, run the laptop down to hibernate cutoff on battery alone, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity and clears the false health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after swapping the A32-K55 cell
The K45 BIOS reads health data from an EEPROM embedded in the battery pack. When a new cell arrives, that EEPROM does not yet hold a charge history the BIOS recognises, so it flags the battery as unknown or degraded. This is not a fault with the replacement cell. Running one complete discharge-to-hibernate followed by an uninterrupted full charge writes the initial learn data and resolves the warning. After two to three cycles, health reporting stabilises.
Laptop shutting down at 20–30% remaining shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The percentage shown on screen is calculated from the old cell's profile, so the displayed figure and the real remaining charge diverge — the cell hits its low-voltage cutoff before the OS expects it. To fix this, complete two full discharge cycles from 100% down to hibernate cutoff with no interruptions. After each full cycle, charge back to 100% without unplugging early. By the second cycle, the fuel gauge IC locks onto the correct curve and the shutdown stops occurring above 10%.