About this replacement
Asus R404 Series — 10.8V Li-ion Replacement Battery (A32-U47)
This 10.8V, 4600mAh (49.68Wh) Li-ion battery replaces the original cell in Asus R404, R404A, R404C, and R404V notebooks. It matches the A32-U47, A41-U47, and A42-U47 OEM part numbers along with Asus board codes 0B110-00090000, 0B110-00090100, and 0B110-00090300. The connector, BMS handshake, and voltage rail are matched to the R404 platform.
- R404 platform compatibility: The R404 series shares a common voltage rail and BMS handshake across the A, C, and V variants. All three sub-models draw from the same battery bay geometry and use the same SMBus communication protocol, which is why one part number covers the full lineup.
- Bench tested on actual hardware: We ran this cell on an R404 chassis and confirmed the BMS initialised correctly on first connection. The SMBus handshake completed without error flags, and the charge controller moved through its full charge cycle without interruption.
- Post-install calibration on the R404: After fitting this battery, run the laptop from 100% down to hibernate-cutoff under normal load — screen on, Wi-Fi active. Then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the false health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after R404 cell swap
The R404 BIOS reads health data stored in the old cell's EEPROM and compares it against the new cell on first boot. Because the new cell has no charge history, the BIOS flags it as degraded or unknown — this is a data mismatch, not a battery fault. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% gives the fuel gauge IC enough data to write accurate capacity values back to the EEPROM. After two to three full cycles, the health indicator updates and the warning clears.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC's stored discharge curve no longer matches the actual voltage behaviour of the new cell. Under combined CPU and display load, the cell hits a voltage cliff that the old curve predicts at 0% — but the OS is still showing 20–30%. The fix is the same calibration cycle: full discharge to hibernate-cutoff, then charge to 100% without interruption. After that cycle the gauge IC recalibrates its cutoff threshold and the shutdown shifts back to the correct low-voltage point near 3.0V per cell.