About this replacement
HP Envy Sleekbook 6 Series — 14.8V Li-Polymer Replacement Battery (EG04XL)
This is a 14.8V, 4050mAh (59.94Wh) lithium-polymer battery for the HP Envy Sleekbook 6 and Envy Sleekbook 6z-1000 series notebooks. It replaces OEM part EG04XL and cross-references HSTNN-DB3T, HSTNN-IB3T, 681951-001, and TPN-C103 among others. Fit it when the original cell no longer holds charge or the laptop loses power the moment you unplug from AC.
- Sleekbook 6 and 6z-1000 platform fit: These models share the same 14.8V four-cell rail, the same physical connector, and the same BMS handshake protocol — which is why one part number covers the full Envy Sleekbook 6 lineup. The EEPROM on this cell carries the correct chemistry flags so the BIOS recognises it without errors at first boot.
- Bench tested on actual hardware: We cycled this cell on a Sleekbook 6 unit and confirmed the BMS accepted the full charge cycle without triggering an over-voltage cutoff. Charge current tapered correctly at the top of the charge curve and the cell held voltage within spec under combined CPU and display load.
- Post-install calibration on the Sleekbook 6: After fitting this cell, run one full discharge until the laptop hibernates, then charge uninterrupted to 100% without interruption. This resets the BIOS battery-learn cycle and clears the false "poor battery health" warning that appears after any cell swap on this platform.
Why the Sleekbook 6 shuts down at 20–30% after a battery swap
The Sleekbook 6 BIOS maps shutdown thresholds against a voltage curve it learned from the original cell. A new cell has a slightly different discharge curve — the fuel gauge IC reads a voltage that the old map treats as critically low even though charge remains. Under combined CPU turbo and backlit display load, voltage sags briefly and the BIOS interprets it as a dead cell. Running two full discharge-to-hibernate and uninterrupted charge-to-100% cycles gives the fuel gauge IC enough data to re-map the curve against the new cell's actual chemistry.
BIOS showing 0% or "unknown battery" on first boot after fitting
This happens when the EEPROM data from the previous cell is still cached in the EC firmware. The system hasn't yet read the new cell's identification registers. Shut the laptop down fully — not sleep or hibernate — remove AC power for 30 seconds, then reconnect AC and boot. This forces the embedded controller to re-poll the battery bus and load the new cell's EEPROM data. After that first full boot on AC, the BIOS should report voltage correctly at 14.8V nominal.