About this replacement
Asus Zenbook UX330UA Series — 11.55V Li-Polymer Replacement Battery (C31N1602)
This is an 11.55V, 4800mAh (55.44Wh) lithium-polymer battery for the Asus Zenbook UX330UA series, including the FB161T, GL192, FB019T, FC115T, and over 46 additional variants. It replaces OEM part numbers C31N1602 and 0B200-02090000. The slim 4.10mm cell profile matches the UX330UA's tight chassis clearance exactly.
- UX330UA platform compatibility: All UX330UA variants share the same 11.55V three-cell configuration, identical connector pinout, and the same BMS handshake protocol — which is why one cell fits the full model range without firmware or connector changes.
- Bench tested on actual hardware: We ran this cell on a UX330UA board under a mixed CPU-plus-display load. The BMS held the 11.55V rail steady and reported state-of-charge accurately to the ACPI layer after two calibration cycles.
- Post-install discharge cycle: After fitting 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 that appears after every cell swap on the UX330UA.
BIOS reporting poor battery health after fitting the replacement cell
The UX330UA BIOS reads health data from EEPROM registers that carry figures from the original cell. A fresh cell has no matching EEPROM history, so the BIOS flags it as degraded immediately after install. This is a calibration gap, not a fault with the replacement. Run one full discharge-to-hibernate followed by an uninterrupted full charge. After two to three cycles, the fuel gauge IC overwrites the stale EEPROM data and the health warning clears.
Laptop shuts down suddenly at 20–30% charge shown on screen
This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell hits a voltage cliff under combined CPU and display load before the OS gauge reaches zero, triggering an immediate shutdown. The OS is reading a curve that no longer matches the physical cell. Discharge fully to hibernate cutoff twice in a row — each cycle trains the fuel gauge IC against the new cell's actual voltage profile and the early shutdowns stop.