About this replacement
Asus VivoBook V451LA — 14.4V Li-Polymer Replacement Battery (B41N1304)
This 14.4V, 3150mAh (45.36Wh) Li-Polymer battery replaces the original B41N1304 cell in the Asus VivoBook V451LA and V451LA-DS51T. It fits the four-cell pack bay directly and connects to the same BMS communication line the laptop expects. Install is straightforward once the back panel screws are removed.
- V451LA and V451LA-DS51T compatibility: Both models share the same 14.4V four-cell Li-Polymer configuration and the same B41N1304 connector pinout. The BMS handshake uses the same SMBus protocol, so the laptop's charge controller recognises this cell without any firmware modification.
- Bench tested on actual hardware: We cycled this battery through charge, full-load discharge, and BMS cutoff on the V451LA platform. The protection circuit responded correctly to over-current and low-voltage thresholds, and the charge controller accepted the cell without fault codes.
- BIOS learn-cycle reset after swap: After installing this battery, run it down fully until the laptop hibernates on its own, then charge it uninterrupted to 100%. This forces the BIOS battery learn cycle to recalibrate against the new cell and clears the inaccurate health warning that appears after every cell replacement.
Why the V451LA BIOS flags a new battery as poor health
The VivoBook BIOS stores battery health data in EEPROM tied to the original cell's cycle count and rated capacity. When a new cell goes in, the EEPROM data no longer matches the actual chemistry, so the BIOS reports degraded or unknown health immediately. This is a data mismatch, not a fault with the replacement battery. Running one complete discharge-to-hibernate followed by an uninterrupted full charge resets that learned data and brings the health indicator back to normal.
Laptop shutting down at 20–30% charge shown on screen
This happens because the fuel gauge IC on the V451LA is still calibrated to the old cell's discharge curve. The gauge thinks 20% remaining maps to a safe voltage, but against a new cell it is reading the curve wrong and calling shutdown too early. The fix is two to three full discharge-and-charge calibration cycles, which let the fuel gauge IC re-map its voltage-to-percentage table against the new cell. After calibration, the gauge should track accurately down to the BMS cutoff at approximately 10.0V under load.