About this replacement
Fujitsu LifeBook S4510 Series — 10.8V Li-ion Replacement Battery (FPCBP25)
This 10.8V, 3400mAh (36.72Wh) Li-ion cell replaces the original battery in the Fujitsu LifeBook S4510, S4530, S4540, and S4542, along with seven additional LifeBook S-series models. It matches the OEM voltage rail and connector pinout for these laptops. Cross-referenced OEM part numbers include FPCBP25, FMVNBP104, FPCBP35, FMVNBP113, FPCBP52, FMVNBP114, FPCBP61, FMVNBP115, and CP024485-01 among others.
- S4510 series compatibility: These LifeBook models share the same 10.8V battery bus, physical form factor, and BMS handshake protocol. The connector pinout and cell group configuration are identical across the S4510, S4530, S4540, and S4542, which is why a single cell covers the range.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on S-series hardware. The BMS communicated correctly with the system board, accepted a full charge without tripping the protection circuit, and reported cell status accurately over SMBus.
- First-cycle calibration on the S4510: After installation, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that routinely appears after any cell swap on this platform.
BIOS reporting battery health as poor after replacement on the LifeBook S-series
The LifeBook S4510 BIOS reads health data stored in the battery's EEPROM and compares it against the old cell's learned parameters. A fresh cell has no history in that register, so the BIOS flags it as degraded or unknown — this is a data mismatch, not a faulty battery. Running the battery learn cycle (full discharge to hibernate cutoff, then uninterrupted charge to 100%) rewrites the EEPROM baseline and brings the health indicator into the normal range. Repeat the cycle once more if the warning persists after the first pass. After two complete cycles the BIOS typically clears the alert entirely.
LifeBook S4510 shutting down at 20–30% charge shown
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The gauge reports 20–30% remaining, but the cell voltage has already dropped below the threshold the system board tolerates under combined CPU and display load — so the laptop cuts out. The old cell's calibration data is still being used as the reference. Run two full discharge-to-hibernate and full-charge cycles; by the second cycle the fuel gauge IC recalibrates and the low-charge shutdown moves down to the correct level near 5%. After calibration, confirm the reported Wh reading in your OS power settings sits close to 36.72Wh.