Uniwill E11-3S4400-S1B1 11.1V Replacement Battery 4400mAh

Uniwill E11 — 11.1V Li-ion Replacement Battery (E11-3S4400-S1B1)

This is an 11.1V Li-ion battery rated at 4400mAh (48.84Wh), built to replace the original cell in the Uniwill E11 notebook. It fits E11 units using OEM part numbers E11-3S4400-S1B1, E11-3S4400-B1B1, E11-3S2200-S1B1, and E11-3S2200-B1B1. If your E11 no longer holds a charge or won't run off AC, this is the direct swap.

• E11 series compatibility: All four OEM part numbers above share the same three-cell 11.1V configuration, connector pinout, and BMS handshake protocol used across the E11 platform — swapping between them is safe on any E11 unit.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on E11-compatible hardware. The BMS communicated correctly with the system, accepted a full charge without fault flags, and held voltage through a sustained load draw without triggering an early cutoff.
• Post-install calibration on the E11: After fitting this battery, run one full discharge down 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 this platform.

BIOS reporting poor battery health immediately after fitting a new E11 cell

The E11's BIOS reads health data from the battery's EEPROM, which carries capacity and cycle figures written by the original manufacturer. A replacement cell arrives with EEPROM values that don't match what the BIOS expects from a fresh install, so it flags the battery as degraded even though the cell is new. This is a data mismatch, not a hardware fault. One full discharge-to-hibernate followed by an uninterrupted full charge gives the BIOS a fresh reference point and typically clears the warning within two cycles.

E11 shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC hasn't yet calibrated against the new cell's actual voltage curve. The gauge underestimates remaining charge, but the real issue is that under full CPU and display load the cell voltage drops sharply — hitting the BMS low-voltage cutoff before the OS gauge reaches 0%. The fix is to let the laptop discharge fully to hibernate twice in a row, then charge each time without interruption. After two complete cycles the gauge IC re-anchors its curve and the cutoff point aligns with actual cell state — verify by checking reported voltage at shutdown, which should sit below 10.5V.