About this replacement
Lenovo Xiaoxin Air 13IWL — 15.36V Li-Polymer Replacement Battery (L17C4PF0)
This is a 15.36V, 2800mAh (43.01Wh) Li-Polymer replacement battery for the Lenovo Xiaoxin Air 13IWL and Xiaoxin Air 13 ultrabook. It slots directly into the same bay as OEM part L17C4PF0 and related numbers including L17M4PF0, SB10W67316, and 5B10R38650. If your original cell has swollen, lost charge capacity, or stopped registering in the BIOS, this is the replacement.
- Xiaoxin Air 13 series compatibility: The 13IWL and standard Xiaoxin Air 13 share the same 15.36V four-cell architecture, connector pinout, and BMS handshake protocol — which is why multiple OEM part numbers (L17C4PF0, L17M4PF0, SB10W67414, 5B10W67405) cross-reference to this single cell pack.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the Xiaoxin Air 13 platform. The BMS communicated correctly with the Lenovo EC, charge current tapered normally at top-of-charge, and no false low-voltage cutoffs appeared under sustained CPU and display load.
- BIOS learn cycle after installation: After fitting this battery, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.
Why the Xiaoxin Air 13 shuts down at 20–30% after a battery swap
The Xiaoxin Air 13 uses a fuel gauge IC that maps voltage curves from the original cell's EEPROM data. A new cell has a different internal resistance profile, so the IC misreads remaining capacity until it recalibrates. Under full CPU and display load, the cell voltage drops faster than the IC expects, triggering an emergency shutdown well above the true empty point. Running two to three full discharge-to-hibernate and full-charge cycles retrains the fuel gauge against the new cell's actual voltage curve. After calibration, the shutdown-at-30% behaviour stops.
BIOS reporting wrong Wh rating after fitting this cell
The Lenovo EC reads Wh rating from EEPROM data embedded in the battery pack, not from live cell measurements. If the value shown in BIOS or Lenovo Vantage differs from 43.01Wh, the EC is still reading cached data from the previous battery or the new pack's EEPROM reflects a slightly different rated figure from the OEM cross-reference. This does not affect actual charge or discharge behaviour. To force a fresh read, fully power down, disconnect AC, reseat the battery connector, then boot and check BIOS under Power — the correct value should populate within one charge cycle.