Fujitsu FMVNBP144 Replacement Battery 10.8V 2600mAh

Fujitsu FMV-BIBLO LOOX P70R / FMV-LIFEBOOK P8210 — 10.8V Li-ion Replacement Battery (FMVNBP144)

This is a 10.8V, 2600mAh Li-ion battery replacing part number FMVNBP144 in the Fujitsu FMV-BIBLO LOOX P70R, FMV-BIBLO LOOX P70S, FMV-LIFEBOOK P8210, FMV-LIFEBOOK P8240, and related ultraportable models. It slots into the original bay using the same connector and locking tab. Capacity matches the factory specification at 28.08Wh.

• LOOX P and LIFEBOOK P series compatibility: These models share the same 10.8V battery rail, physical bay dimensions, and BMS handshake protocol — which is why one part number covers both the LOOX and LIFEBOOK P lines. The connector pinout and latch position are identical across this platform generation.
• Bench tested on actual hardware: We ran the cell through full charge and load cycles on a P-series unit. The BMS communicated correctly with the system, charge termination triggered at the right cutoff voltage, and the protection circuit responded to overcurrent conditions as expected.
• Post-installation calibration on the LOOX P series: After fitting a new cell, run the battery down to the system's hibernate cutoff point, then charge uninterrupted to 100% without using the laptop. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that almost always appears after swapping cells in this platform.

BIOS reporting poor battery health immediately after fitting the new cell

The Fujitsu BIOS reads health data from the battery's EEPROM, which stores historical charge data from the old cell. When a new cell goes in, that EEPROM data is either absent or mismatched, so the system flags the battery as degraded before it has run a single cycle. This is a firmware reading problem, not a fault with the replacement cell. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100% — this resets the learn cycle and updates the BIOS health register. After two or three full cycles, the health indicator should normalise.

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

This shutdown behaviour is a voltage cliff issue, not a gauge error. Under combined CPU and display load, the cell voltage drops faster than the fuel gauge IC can recalculate state-of-charge, and the system hits the low-voltage protection threshold before the displayed percentage reaches zero. It is most noticeable on the LOOX P series because the ultraportable chassis runs the CPU and display from the same power rail with limited headroom. Calibrate the fuel gauge by running a full uninterrupted discharge to hibernate, then charging to 100% at least twice — this synchronises the IC's capacity model with the actual cell. If shutdown still occurs above 15% after three calibration cycles, check that the BIOS battery wear threshold setting is not set above its default value.