Fujitsu FPCBP535 Compatible Battery 7.2V 3400mAh

Fujitsu FUTRO MU937 — 7.2V Li-Polymer Replacement Battery (FPCBP535)

This 7.2V 3400mAh Li-Polymer battery replaces the original FPCBP535 (also listed as FPB0339S and CP737633-01) in the Fujitsu FUTRO MU937 thin client. The FUTRO MU937 is a compact enterprise thin client used for remote desktop and virtualisation workloads. Swap this cell when the original no longer holds a charge or the unit has lost portable operation entirely.

• FUTRO MU937 fitment: The MU937 uses a slim 259.80 × 104.20 × 6.60mm Li-Polymer cell tied directly to the BMS on the mainboard. The BMS reads cell authentication data at boot — this replacement carries the correct EEPROM profile to clear the unknown-battery flag that appears after swapping cells.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge under a simulated thin-client load. The BMS accepted the cell without fault codes, and the fuel gauge IC locked onto the correct 24.48Wh rating within two calibration cycles.
• FUTRO MU937 first-cycle procedure: After installing, run the unit until it hibernates on low battery, then charge uninterrupted to 100% without interruption. This forces the BIOS battery learn cycle to complete against the new cell and clears the inaccurate health warning that shows up after every cell replacement on this platform.

Why the FUTRO MU937 BIOS reports poor battery health immediately after a cell swap

The FUTRO MU937 stores battery health data in EEPROM on the original cell. When you fit a new cell, the BIOS compares current readings against that stale data and flags the battery as degraded or unknown — even when the new cell is fully functional. This is not a fault with the replacement cell. Running one complete discharge-to-hibernate then a full uninterrupted charge resets the learn cycle and writes fresh baseline data. After two full cycles the health indicator should return to normal in both the BIOS and the OS.

FUTRO MU937 shutting down at 20–30% charge remaining

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The gauge reads a higher state of charge than the cell can sustain, so when real voltage drops under load the BMS triggers an emergency cutoff — appearing as a sudden shutdown at what the OS still shows as 20–30%. Force a full discharge to hibernate-cutoff and then charge to 100% without removing power. Repeat twice. After those calibration cycles the gauge tracks the true voltage floor and shutdowns at falsely high percentages stop.