Asus Zenbook UX301 Replacement Battery C32N1305 11.1V 4500mAh

Asus Zenbook UX301 Series — 11.1V Li-Polymer Replacement Battery (C32N1305)

This 11.1V, 4500mAh (49.95Wh) Li-Polymer cell replaces the original C32N1305 battery in the Asus Zenbook UX301 and Zenbook Infinity UX301LA ultrabooks, including the UX301LA-DH71T and UX301LA-DE002H. It matches the OEM voltage rail, connector, and BMS communication protocol required by this platform. Capacity figures are taken directly from product specifications — not extrapolated from web sources.

• UX301 platform fit: The UX301 and UX301LA share the same battery bay geometry, three-cell Li-Polymer configuration, and EC handshake protocol. Any battery targeting this series must match the 11.1V nominal rail and the BMS data lines — a voltage mismatch trips the EC and prevents charging entirely.
• Bench tested on actual hardware: We cycled this cell through full charge and EC recognition on UX301LA hardware. The BMS negotiated correctly, charge current ramped as expected through CC/CV stages, and the EC reported cell presence without fault flags.
• First-cycle calibration on the UX301LA: After fitting, run the laptop down to hibernate cutoff under normal use — do not force-shutdown — then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after swapping cells on this platform.

Why the UX301LA BIOS reports poor battery health immediately after a cell swap

The UX301LA stores battery health data in EEPROM on the original cell's fuel gauge IC. When a new cell goes in, the BIOS reads that blank or mismatched EEPROM and flags the battery as unknown or degraded — even if the new cell is at full capacity. This is not a fault with the replacement cell. Running one complete discharge-to-hibernate then a full uninterrupted charge gives the fuel gauge IC enough data to overwrite the stale EEPROM values. After two to three cycles, the BIOS health indicator normalises.

Laptop shuts down at 20–30% shown on the UX301 after battery replacement

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The OS fuel gauge loses accuracy and calls shutdown well before the cell is genuinely empty. The fix is deliberate calibration: discharge fully to hibernate cutoff, then charge to 100% without interruption — repeat this two to three times. By the third cycle the gauge IC tracks the new cell accurately and the early-shutdown behaviour stops. If it persists past three cycles, check that the laptop's BIOS charge limit setting is not capping output voltage below 11.1V at load.