About this replacement
Dell XPS 13D-8808 / XPS13D-5701 — 7.4V Li-Polymer Replacement Battery (TU131-TS63-74)
This is a 7.4V, 6040mAh (44.7Wh) lithium-polymer replacement battery for the Dell XPS 13D-8808, XPS13D-5701, Schenker S306, XPS13D-8708T, and over 30 additional XPS 13 variants. It replaces OEM part number TU131-TS63-74 using the same flat-cell pouch format and connector the original shipped with. Capacity matches the factory specification listed in Dell's own service documentation for this chassis.
- XPS 13 chassis compatibility: These models share the same slim unibody tray, identical JST-style connector pinout, and the same BMS handshake protocol over the SMBus line — which is why one cell part number spans this many SKUs without modification.
- Bench tested on actual hardware: We ran this cell on the XPS 13D-8808 platform, confirmed full SMBus communication between the cell BMS and the EC, and verified the charge controller stepped through CC-CV correctly without tripping the over-current threshold on initial contact.
- Post-install calibration on XPS 13 platforms: After fitting this cell, run the laptop down to hibernate cutoff under normal load, then charge uninterrupted to 100% without using the machine. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Dell XPS hardware.
Laptop shutting down at 20–30% remaining after battery swap
This is a voltage-cliff issue, not a capacity defect. Under sustained CPU and display load, the new cell's terminal voltage drops faster than the fuel gauge IC expects based on the old cell's discharge curve. The EC interprets the sudden voltage dip as empty and triggers an emergency shutdown. Running two full calibration cycles — discharge to hibernate, charge to 100% uninterrupted — lets the fuel gauge IC re-map the new cell's voltage curve. After calibration, shutdown behaviour should align with the displayed percentage.
BIOS reporting battery health as poor or "Unknown" immediately after replacement
The Dell BIOS reads health data from the cell's EEPROM on every boot and compares it against the discharge history stored in the EC. A fresh cell has no accumulated cycle data, so the EC flags it as degraded or unrecognised until it completes a learn cycle. This is not a fault with the cell. Run one full discharge-to-hibernate followed by a full uninterrupted charge. On the next boot, the BIOS health indicator should update to reflect the new cell's actual state.