About this replacement
Panasonic CF-XZ6 Series — 7.6V Li-Polymer Replacement Battery (2-424866S2-B01)
This is a 7.6V 3500mAh (26.6Wh) lithium-polymer replacement battery for the Panasonic Toughbook CF-XZ6 series. It fits the CF-XZ6, CF-XZ62, CF-XZ62DCQR, CF-XZ62FKQR, and over 36 additional CF-XZ6 variants. The OEM part number is 2-424866S2-B01.
- CF-XZ6 series fit: All CF-XZ6 variants share the same 7.6V battery bay, connector pinout, and BMS handshake protocol. The EEPROM communication between battery and BIOS uses the same data frame across the full CF-XZ6 lineup, so one cell covers all these models without adapter or firmware conflict.
- Bench tested on actual hardware: We ran this cell on a CF-XZ62 unit and logged charge cycles from depleted to full. The BMS accepted the cell without flagging unknown device errors, held charge termination correctly at 8.7V, and passed BIOS battery information queries with accurate Wh reporting.
- First-cycle calibration on the CF-XZ6: After installing this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This forces the CF-XZ6 fuel gauge IC to re-learn the new cell's actual capacity curve and clears the inaccurate health warning the BIOS displays after every cell swap.
BIOS reporting battery health as poor immediately after installing a new cell
The CF-XZ6 BIOS reads health data stored in the battery's EEPROM. When a new cell arrives, the EEPROM holds factory default values that don't match the BIOS's learned baseline from the original battery. The system interprets this mismatch as degraded health rather than a fresh cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge resets the learn cycle and updates the BIOS health register correctly.
CF-XZ6 shutting down abruptly at 20–30% charge shown
This is a voltage cliff issue, not a capacity reporting fault. When the CPU, display, and radios draw peak load simultaneously, the cell voltage drops faster than the fuel gauge IC can track. The BIOS sees the voltage fall below the cutoff threshold — typically around 6.0V — and triggers an emergency shutdown before the percentage readout catches up. If this happens on a new cell, run two full calibration cycles first; if it persists after calibration, check BIOS firmware version, as some CF-XZ6 builds require an update to handle the 7.6V cell's discharge curve accurately.