About this replacement
Samsung Ultrabook 940X3G — 7.6V Li-Polymer Replacement Battery (AA-PLVN4CR)
This 7.6V, 6100mAh (46.36Wh) lithium-polymer cell replaces the original AA-PLVN4CR battery in the Samsung Ultrabook 940X3G. It fits the thin-profile chassis of this ultrabook and connects via the original flex ribbon connector. Voltage and capacity match the OEM specification exactly.
- 940X3G platform fit: The 940X3G uses a sealed ultrabook chassis with a dedicated battery bay and a proprietary flex connector tied to the BMS handshake. This cell carries the correct EEPROM header data so the system firmware recognises it without a hardware fault flag on first boot.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the 940X3G platform. The BMS accepted the cell immediately, reported state-of-charge correctly after two calibration cycles, and showed no voltage sag under sustained CPU and display load.
- First-cycle calibration on the 940X3G: After fitting this cell, run the laptop down to hibernate cutoff on a normal workload — do not force-shutdown. 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 this platform.
BIOS reporting poor battery health after fitting the AA-PLVN4CR replacement
Samsung's BIOS reads health data from the EEPROM stored on the battery controller, not from live cell measurements. When a new cell is installed, the EEPROM registers no learned cycles, so the firmware flags it as degraded before any calibration has run. This is a firmware state issue, not a cell fault. One full discharge-to-hibernate followed by an uninterrupted charge to 100% writes fresh learn-cycle data and clears the warning. After two complete cycles the health indicator should read normal.
940X3G shutting down at 20–30% shown on the fuel gauge
The fuel gauge IC in the 940X3G estimates remaining capacity from voltage curves mapped to the original cell. A new cell has a slightly different voltage-to-capacity curve until it has been calibrated. Under full CPU and display load, voltage drops faster than the gauge predicts, and the BMS triggers a hard shutdown before the displayed percentage reaches zero. This is not a faulty cell — it is a calibration gap. Run two full discharge-to-hibernate and charge-to-100% cycles to remap the curve. After calibration the shutdown threshold should align with 5% or below.