Fujitsu Stylistic Q584 Replacement Battery 3.8V 9500mAh

Fujitsu Stylistic Q584 — 3.8V Li-Polymer Replacement Battery (CP678530-01)

This 3.8V, 9500mAh (36.1Wh) lithium-polymer cell replaces the original battery in the Fujitsu Stylistic Q584 2-in-1 hybrid tablet. It fits the slim chassis directly and matches the connector and BMS handshake of the factory unit. OEM part numbers CP678530-01, FPB0310, and FPCBP415 all cross to this cell.

• Stylistic Q584 fitment: The Q584 uses a flat Li-Polymer pouch cell at 3.8V nominal. The BMS on this device checks cell chemistry and voltage profile on first boot — this replacement matches both, so the firmware recognises it without a connector workaround or firmware patch.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Q584 platform. The BMS accepted the cell, reported charge state correctly after two cycles, and held voltage above the firmware cutoff threshold under simultaneous display and CPU load.
• First-cycle calibration on the Q584: After installing, run the tablet down to hibernate cutoff — do not force-shutdown. Then charge uninterrupted to 100% without using the device. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor after replacing the Q584 cell

The Q584's BIOS reads EEPROM data written by the original cell — cycle count, charge history, and rated capacity. A new cell has blank or mismatched EEPROM values, so the BIOS flags it as degraded even when the cell is physically good. This is not a fault with the replacement. Run one full discharge to hibernate cutoff followed by an uninterrupted charge to 100% — the BIOS learn cycle rewrites its internal baseline against the new cell. After two to three cycles the health status normalises.

Q584 shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC's charge map still reflects the old cell's voltage curve. The new cell hits a voltage cliff — where cell voltage drops sharply under combined CPU and display load — at a different state of charge than the gauge expects. The firmware reads that voltage drop as empty and triggers shutdown before the gauge hits zero. Force a full discharge to hibernate cutoff, then charge to 100% twice without interruption. After those calibration cycles the gauge IC re-maps the curve and the shutdowns stop.