About this replacement
Dell XPS 13 7390 — 7.6V Li-Polymer Replacement Battery (52TWH / XX3T7)
This 7.6V, 6500mAh (49.4Wh) lithium-polymer cell is a direct replacement for the Dell XPS 13 7390 ultrabook. It fits the 7390 chassis and connects via the original ribbon cable and BMS handshake. Use the capacity figure above — not third-party listings — as the reference spec.
- XPS 13 7390 fitment: The 7390 uses a slim dual-cell Li-Polymer pack with a 264.52 × 114.80 × 5.00mm footprint. The BMS communicates over SMBus with the EC firmware, so the physical connector, pin count, and cell voltage must match exactly. This cell meets all three.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the XPS 13 7390 platform. The BMS handshook correctly on first insertion, the EC reported cell chemistry as expected, and the charge controller stepped through CC/CV without tripping a fault. No thermal events were recorded.
- First-cycle recalibration on the XPS 13: After installing, run one full discharge until the laptop hibernates at its cutoff threshold, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on almost every fresh cell swap in this model.
BIOS reporting battery health as poor after replacement on the XPS 13 7390
The XPS 13 BIOS reads health data from EEPROM registers stored in the old battery's fuel gauge IC. When a new cell is installed, those registers are blank or carry different baseline values, so the BIOS flags the battery as degraded even though the cell is new. This is not a fault with the replacement — it is a calibration state. Run one full discharge-to-hibernate cycle followed by a full uninterrupted charge. After two to three cycles the EC rewrites the health registers and the warning clears.
XPS 13 7390 shutting down at 20–30% shown on the fuel gauge
This happens when the fuel gauge IC has not yet mapped the new cell's actual voltage curve. The gauge still uses the old cell's discharge profile, so it misreads the remaining charge and the laptop hits a voltage cliff before the displayed percentage reaches zero. Under full CPU and display load the voltage drop is faster, which is why this fault shows up most during video playback or compile tasks. Run two full discharge-to-hibernate cycles back-to-back and the gauge IC will recalibrate against the new cell — shutdowns should stop at that point.