Fujitsu FMVNBP117 Replacement Battery 10.8V 4400mAh

Fujitsu FMV-BIBLO LOOX T50E Series — 10.8V Li-ion Replacement Battery (FMVNBP117)

This is a 10.8V, 4400mAh (47.52Wh) Li-ion replacement battery for the Fujitsu FMV-BIBLO LOOX T50E and related LOOX T-series notebooks. It fits the T50E, T50E/W, T50G/W, T55G, and over fifteen additional LOOX T-series models sharing the same connector and BMS handshake. OEM part numbers covered include FMVNBP117, FMVNBP118, FPCBP100, FPCBP68, FPCBP69, and several cross-references.

• LOOX T-series platform fit: These models share a common connector pinout, 10.8V nominal rail, and the same BMS communication protocol — the replacement cell negotiates with the LOOX T-series controller the same way the original did, without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge on the LOOX T-series platform. The BMS accepted the new cell, fuel gauge initialised correctly, and charge terminated cleanly at full capacity without false fault flags.
• LOOX T-series BIOS recalibration after swap: After fitting this battery, run one complete discharge down to the hibernate cutoff — do not interrupt it — then charge uninterrupted to 100%. This lets the BIOS battery learn cycle reset against the new cell and clears the inaccurate health warning that appears after every cell replacement on this platform.

BIOS reporting battery health as poor immediately after replacement

The LOOX T-series BIOS stores charge history and health metrics in the original cell's EEPROM. When a new cell goes in, the BIOS compares live readings against the old EEPROM baseline and flags a mismatch as poor health. The battery itself is not faulty — the firmware simply hasn't learned the new cell's characteristics yet. Run one full discharge-to-hibernate cycle followed by a full uninterrupted charge. After two to three cycles, the BIOS health status recalibrates and the warning clears.

Laptop shuts down at 20–30% charge shown on the gauge

This happens when the fuel gauge IC is still calibrated to the old, degraded cell. The old cell had a steep voltage cliff at low state-of-charge — the gauge learned to shut down early to protect it. The new cell holds voltage further into its discharge curve, but the IC doesn't know that yet. Force a full discharge to the hibernate cutoff, let the system sit for two minutes, then charge continuously to 100% — this recalibrates the fuel gauge IC against the new cell's actual voltage profile.