Motile M142 Laptop Replacement Battery 11.4V 4100mAh

Motile M142 — 11.4V Li-Polymer Replacement Battery (PF4WN-00-13-3S1P-0)

This is an 11.4V, 4100mAh (46.74Wh) lithium-polymer battery for the Motile M142 laptop. It replaces part numbers PF4WN-00-13-3S1P-0, PF4WN-00-17-3S1P-0, PF4WN-03-17-3S1P-0, and U45A1HPFS01. The M142 is a slim notebook, and this flat Li-Polymer cell is cut to the same 246.40 × 65.80 × 6.40mm footprint as the original.

• M142 platform fit: All four OEM part numbers listed above share the same 3S1P cell configuration, 11.4V nominal voltage rail, and connector pinout. The BMS handshake protocol is identical across the revision — the suffix change reflects a supplier batch update, not a hardware change.
• Bench tested on actual hardware: We ran a full charge-discharge cycle on the M142 with this cell installed. The BMS negotiated correctly with the system board, the charge controller accepted the full 46.74Wh rated capacity, and no fault codes appeared in the battery EEPROM log.
• Post-install calibration on the M142: After fitting this battery, run one full discharge until the system hibernates on its own, then charge uninterrupted to 100% without unplugging early. The M142 BIOS uses this cycle to reset its battery-learn table — skipping it causes the fuel gauge to read inaccurately for weeks.

BIOS reporting poor health or "Unknown Battery" after fitting a new cell

When the M142 BIOS reads the EEPROM on a replacement cell, it compares the stored cycle count and rated Wh value against its own health table. A fresh cell has a cycle count of zero and clean EEPROM data, which can trigger a mismatch warning against the degraded profile the BIOS cached from the old pack. This is a firmware interpretation issue, not a fault with the replacement cell. Run the calibration cycle described above — one full drain to hibernate, one uninterrupted charge to 100% — and the BIOS learn cycle will write new baseline data and clear the warning.

M142 shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The old cell's curve data is still stored, so the gauge shows 25% while the actual cell voltage has already dropped below the BMS cutoff threshold. The laptop shuts down because the hardware voltage floor trips before the OS percentage reaches zero. Run two full calibration cycles — drain to hibernate cutoff, then charge to 100% — and check that the battery voltage at idle reads between 11.1V and 11.4V before the next discharge.