About this replacement
Elonex Webbook — 11.1V Li-Polymer Replacement Battery (NB1)
This is an 11.1V, 2600mAh (28.86Wh) Li-Polymer replacement battery for the Elonex Webbook subnotebook. It matches the OEM part number NB1 and restores portable power to the Webbook when the original cell can no longer hold a charge. This is the correct fit for users keeping legacy Webbook hardware in daily use away from a wall outlet.
- Webbook platform fit: The Webbook uses a single-battery bay with a connector and BMS handshake specific to this subnotebook line. The NB1 part number is the only cell that matches this bay geometry and communicates correctly with the Webbook's charge controller without triggering a refusal-to-charge condition.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Webbook platform. The BMS handshake completed without error, charge current stepped down correctly at the CV phase, and the protection circuit tripped at the expected low-voltage cutoff without dropping the system mid-session.
- First-cycle reset on Webbook: After fitting this battery, run a full discharge to hibernate cutoff, then charge uninterrupted to 100%. This forces the Webbook's fuel gauge IC to recalibrate against the new cell and clears the inaccurate battery health warning that appears after any cell swap on this platform.
BIOS reporting poor battery health immediately after fitting the NB1
The Webbook stores battery health data in EEPROM from the previous cell. When a new cell is fitted, the BIOS reads the old EEPROM values and flags the battery as degraded before any real measurement occurs. This is a data mismatch, not a fault with the replacement cell. Run one full discharge-to-hibernate then a complete uninterrupted charge — this triggers the battery learn cycle and overwrites the stale EEPROM values with accurate figures from the new cell.
Webbook shutting down abruptly while the gauge still shows charge remaining
This happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The gauge reports a percentage based on the old cell's profile, so the Webbook shuts down at what looks like 20–30% because the real cell voltage has already hit the protection cutoff. It takes two to three full discharge-and-charge cycles for the gauge IC to map the new cell accurately. After those calibration cycles, the displayed percentage and the actual cutoff point will align — monitor resting voltage after a full charge, which should sit at approximately 12.6V.