About this replacement
Asus A2 / A2000 Series — 14.8V Li-ion Replacement Battery (A42-A2)
This is a 14.8V, 4400mAh (65.12Wh) Li-ion battery for the Asus A2 and A2000 series notebooks. It replaces OEM part numbers A42-A2, 90-N7V1B1000, 90-N7V1B1200, and 70-N7V1B3000. If your original pack won't hold a charge or the laptop dies unplugged, this is the direct cell replacement.
- A2 and A2000 series compatibility: The A2, A2000C, A2000D, and 24 additional A2000 variants all run the same 14.8V four-cell Li-ion architecture with an identical connector and BMS handshake — one part number covers the entire platform.
- Bench tested on actual hardware: We ran this cell on an A2000 unit and cycled it through full charge and discharge. The BMS responded correctly at both ends — charge termination triggered at 16.8V and low-voltage cutoff held at 11.0V without fault codes.
- First-cycle reset after install: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap on A2-series boards.
Why the A2000 BIOS flags a new battery as poor health immediately after swap
The A2000 BIOS stores historical charge data in EEPROM on the old battery pack. When a new cell arrives, the BIOS has no learned data for it and defaults to a poor or unknown health status. This is not a battery fault — it is a calibration state. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% writes fresh data to the BIOS learn table. After two to three full cycles, the health indicator normalises.
Laptop shuts down at 20–30% charge shown on A2 series
This happens when the cell voltage drops below the sustainable threshold under combined CPU and display load before the fuel gauge reaches zero. The old cell's discharge curve is still programmed into the fuel gauge IC, so it reads 25% while the actual cell voltage has already hit the cutoff cliff. The fix is a full calibration cycle — discharge fully until the laptop hibernates on its own, then charge to 100% without interruption. After two cycles the fuel gauge IC recalibrates against the new cell's actual voltage curve and the early shutdowns stop.