About this replacement
Compaq OmniBook 4111 — 11.1V Li-ion Replacement Battery (F1466A)
This 11.1V, 6600mAh (73.26Wh) Li-ion cell replaces the original F1466A battery in the Compaq OmniBook 4111 and related OmniBook 4100-series notebooks. It fits the OmniBook 4101, 4104, 4107, and 4111 along with nine additional OmniBook variants sharing the same connector and voltage rail. Capacity figures are sourced from the product data — not estimated from web listings.
- OmniBook 4100-series platform fit: The 4101, 4104, 4107, and 4111 all share the same three-cell 11.1V architecture, the same F1466A connector pinout, and the same BMS handshake protocol. One cell revision covers the entire series without modification.
- Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the OmniBook platform and confirmed the BMS communicates state-of-charge data correctly to the host system. The protection circuit responded to cutoff thresholds within spec.
- Post-swap discharge cycle on the OmniBook: After installing this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning the OmniBook BIOS displays after every cell replacement.
BIOS reporting battery health as poor after installing the F1466A cell
The OmniBook BIOS stores charge history in the original cell's EEPROM. When a new cell arrives, the BIOS reads no learned data and flags health as poor or unknown — this is a firmware response, not a cell defect. Running one full discharge-to-hibernate followed by a complete uninterrupted charge gives the BIOS enough data to rebuild its health model. After two to three full cycles, the health indicator corrects itself. No BIOS update or driver change is required.
OmniBook shutting down abruptly at 20–30% charge shown on screen
This symptom points to a fuel gauge IC that has not yet calibrated against the new cell's actual chemistry. The gauge IC learned the voltage-to-capacity curve of the degraded original cell, so it reads the new cell's discharge curve incorrectly and calls cutoff too early. The fix is the same full discharge-to-hibernate cycle: let the system reach 0% and power off on its own, then charge to 100% without interruption. After two cycles the gauge re-maps to the new cell and the early shutdown stops. Target charge voltage to confirm full charge is 12.6V across the pack terminals.