Dell XPS 14 11.1V Replacement Battery 08PGNG 4400mAh

Dell XPS 14 / XPS 15 Series — 11.1V Li-ion Replacement Battery (08PGNG)

This is a 11.1V, 4400mAh (48.84Wh) Li-ion replacement battery for the Dell XPS 14 (L401X) and XPS 15 (L501X) series ultrabooks. It replaces OEM part numbers including 08PGNG, J70W7, JWPHF, R4CN5, and R795X. If your original cell no longer holds a charge or Dell diagnostics flag it as degraded, this cell fits the same bay and connector.

• XPS 14 and XPS 15 L-series compatibility: The L401X and L501X platforms share the same 11.1V three-cell architecture, connector pinout, and BMS handshake protocol. That is why one part number covers both chassis — the power rail and SMBus communication lines are identical across the two boards.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an L401X board. The BMS negotiated correctly over SMBus, cell voltage held within 1% of spec across all three cells at peak draw, and the OS reported state-of-charge accurately after two calibration cycles.
• Post-install calibration on Dell XPS: After fitting this cell, run the laptop on battery only until it reaches hibernate cutoff — do not interrupt the discharge. Then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the spurious health warning that appears after every cell swap on the XPS platform.

BIOS reporting poor battery health immediately after fitting a new cell

Dell's BIOS reads health data from EEPROM registers on the battery controller — not from live cell voltage. When a replacement cell arrives, those registers reflect the new cell's factory defaults, which do not match the charge history the BIOS expects from a broken-in battery. The BIOS interprets this mismatch as a fault and flags the battery as degraded or unknown. Run one full discharge-to-hibernate cycle followed by a full uninterrupted charge to 100%. After two complete cycles, the BIOS learn routine re-writes those registers against measured capacity and the health warning clears.

Laptop shuts down at 20–30% shown on the fuel gauge

This is a voltage cliff issue, not a capacity issue. Under combined CPU and display load the cell voltage drops faster than the fuel gauge IC can track — the gauge still reads 20–30% but the cell has already fallen below the BMS cutoff threshold of approximately 9.0V for this three-cell pack. The fuel gauge IC needs two to three full calibration cycles against the new cell before its discharge curve model is accurate. Run the calibration cycle described in the care tip above, and confirm the issue resolves before assuming a faulty cell.