About this replacement
Asus F52 / F82 / K40 Series — 11.1V Li-ion Replacement Battery (A32-F82)
This is an 11.1V Li-ion battery rated at 4400mAh (48.84Wh), replacing part number A32-F82 and its cross-references including A32-F52 and L0690L6. It fits the Asus F52, F82, and K40 notebook series, along with several other Asus laptop lines sharing the same battery bay and connector format. Install it when the original cell no longer holds charge or the system flags battery health as poor.
- F52, F82, and K40 platform fit: These models share the same 11.1V three-cell battery rail, identical connector pinout, and compatible BMS handshake. The BIOS on each platform reads cell data over the SMBus line — the replacement cell carries matching communication data so the system recognises it without firmware errors.
- Bench tested on actual hardware: We cycled this cell on an F82 unit and confirmed the BMS completed a full charge cycle without tripping a fault, reaching 100% charge with stable voltage across all three cell groups. SMBus communication stayed clean throughout discharge.
- First-cycle calibration after install: After fitting this battery, run the laptop on battery power until it hibernates at low charge, then charge uninterrupted to 100% without interruption. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity data and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting battery health as poor immediately after replacement
The Asus BIOS reads cycle count and state-of-health data stored in the battery's EEPROM. A new cell ships with a different EEPROM profile than the old cell, so the BIOS compares values, finds a mismatch, and flags poor health — even though the cell is new. This is not a fault with the replacement. Running one full discharge-to-hibernate followed by a complete uninterrupted charge resets the learn cycle and writes accurate data to the fuel gauge IC. After two to three full cycles, the health indicator returns to normal.
Laptop shuts down with 20–30% charge still showing on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The IC uses data from the old cell to predict cutoff, so when the new cell's voltage drops sharply under CPU and display load, the system hits the hardware low-voltage cutoff before the gauge reaches 0%. It is not a capacity defect. Run two full discharge cycles — draining to hibernate each time — and the gauge IC maps the new cell's voltage cliff accurately. After calibration, shutdowns at 20–30% stop and the percentage tracks real remaining capacity down to around 3.0V per cell.