About this replacement
Lenovo ThinkPad X280 — 11.46V Li-Polymer Replacement Battery (01AV431)
This 11.46V, 4050mAh (46.41Wh) Li-Polymer battery replaces the original cell in the Lenovo ThinkPad X280 12.5-inch ultrabook. It covers OEM part numbers 01AV431, 01AV470, 01AV471, 01AV472, and the full L17/SB10 series. Install it when your original cell no longer holds charge or triggers a health warning in the BIOS or Windows Battery Report.
- ThinkPad X280 platform fit: All X280 variants — including 20KFA009CD, 20KFA002CD, and 20KFA01VCD — share the same 11.46V three-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol. One part number covers the full production run.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an X280 unit. The BMS communicated correctly with the BIOS, reported accurate Wh data, and held stable voltage under sustained CPU and display load without triggering an unexpected cutoff.
- First-cycle reset procedure: After installing, let the laptop discharge fully until it hibernates, then charge uninterrupted to 100% without interrupting the session. This forces the ThinkPad's fuel gauge IC to re-learn the new cell's capacity curve and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting battery health as poor immediately after replacement
The ThinkPad BIOS reads battery health from EEPROM data written by the original cell during its service life. A new cell arrives with factory EEPROM values that don't match the charge history the BIOS expects, so it flags the battery as degraded or unknown. This is a data mismatch — not a fault with the new cell. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% lets the fuel gauge IC rewrite accurate cycle data and clears the warning on the next boot.
Laptop shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC is still calibrated against the old, degraded cell's voltage curve. The new cell hits a voltage cliff — where cell voltage drops sharply under combined CPU and display load — at a state-of-charge that doesn't match what the OS is displaying. The system interprets the voltage drop as an emergency and cuts power before the displayed percentage reaches zero. Complete two full discharge-to-hibernate and uninterrupted full-charge cycles to recalibrate the gauge; after that, shutdown should not occur above 5% remaining.