Clevo NL40BAT-3 11.4V Laptop Replacement Battery 3150mAh

Clevo NL40MU / NL41MU Series — 11.4V Li-Polymer Replacement Battery (NL40BAT-3)

This is an 11.4V, 3150mAh (35.91Wh) Li-Polymer battery for Clevo NL40MU, NL40PU, NL41MU, NL41PU, and compatible NL-series notebook models. It replaces OEM part NL40BAT-3 and restores portable operation when the original cell no longer holds a usable charge. Voltage and connector match the original spec exactly.

• NL40 / NL41 platform compatibility: The NL40 and NL41 share the same battery bay dimensions, three-cell 11.4V architecture, and BMS communication protocol. The NL40BAT-3 fits both MU and PU variants without modification because the connector pinout and charge termination handshake are identical across the series.
• Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and re-charge on an NL40-series unit. The BMS negotiated charge termination correctly at 12.6V, and protection circuits tripped at the expected low-voltage cutoff without nuisance shutdowns under sustained CPU and display load.
• Post-install calibration on Clevo NL-series: After fitting, discharge the laptop under normal use until it hibernates on its own, then charge uninterrupted to 100% without using the machine. This resets the BIOS battery learn cycle and clears the inaccurate health or low-capacity warning that appears in BIOS and Windows after every cell swap.

BIOS reporting poor battery health immediately after installing NL40BAT-3

The Clevo BIOS reads health data from EEPROM embedded in the battery pack, not from a live capacity measurement. When a new cell arrives, the EEPROM contains factory default values that do not match the laptop's stored wear history from the previous pack. BIOS interprets the mismatch as a degraded or unknown battery and flags it accordingly. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100% — this forces a learn cycle that writes fresh data and clears the health warning.

Laptop shutting down at 20–30% shown after battery swap

This happens because the fuel gauge IC is still calibrated to the old cell's voltage curve. The new Li-Polymer cell has a slightly different voltage-to-capacity profile, so the IC underestimates remaining charge and triggers a shutdown before the cell is actually empty. It is not a fault with the replacement battery. Complete two or three full discharge and charge cycles without interruption — after each cycle the fuel gauge IC recalibrates against the new cell's actual voltage curve, and the early shutdown point moves back toward 0%.