About this replacement
Dell Latitude E6400 ATG — 11.1V Li-ion Replacement Battery (GU715)
This is an 11.1V, 8800mAh (97.68Wh) Li-ion replacement battery for the Dell Latitude E6400, E6400 ATG, E6400 XFR, and 6400 ATG. It replaces a long list of Dell OEM part numbers including GU715, MP307, RG049, TX283, and KY265, among others. If your original battery no longer holds a charge or the system reports poor health, this cell restores full portable operation.
- E6400 platform compatibility: The E6400, E6400 ATG, and E6400 XFR all share the same battery bay geometry, 11.1V rail, and SMBus BMS handshake. One cell fits all three variants because Dell standardised the connector pinout and charge circuit across this generation.
- Bench tested on actual hardware: We ran this cell on an E6400 ATG unit and confirmed the BMS completed a full charge cycle without tripping a fault. The SMBus communication initialised correctly and the system accepted the cell without error on the first boot.
- Post-install calibration on the E6400: After fitting this cell, run a full discharge until the laptop hibernates at low battery, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell data and clears the inaccurate health warning that appears after every cell swap on this platform.
BIOS reporting battery health as poor immediately after replacement
The E6400 BIOS reads health data from the battery's EEPROM on every boot. When a new cell arrives, the EEPROM cycle count is zero but the BIOS compares it against the previous cell's stored data, which flags a mismatch. This is not a fault with the replacement cell — it is a stale reference in firmware. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100%, and the BIOS learn cycle will rewrite the reference data. After two to three full cycles the health indicator normalises.
Laptop shuts down abruptly at 20–30% charge shown
This happens when the cell voltage drops below the BMS cutoff threshold under combined CPU and display load, even though the fuel gauge still reads 20–30% remaining. The fuel gauge IC has not yet calibrated its discharge curve against the new cell's chemistry, so the percentage readout is inaccurate at the bottom of the charge range. The fix is the same calibration cycle: fully discharge to hibernate, then charge to 100% without interruption. After two full cycles the fuel gauge IC maps the actual voltage-to-capacity curve and the shutdowns stop. Check that the resting cell voltage reads at least 11.1V before starting the cycle.