About this replacement
HP Pavilion TouchSmart SleekBook 14 / 15 — 14.8V Li-ion Replacement Battery (HY04)
This is a 14.8V, 2200mAh (32.56Wh) Li-ion battery for the HP Pavilion TouchSmart SleekBook 14 and SleekBook 15 series. It replaces OEM part HY04 and cross-references HSTNN-YB4U, HSTNN-IB4U, HSTNN-LB4U, and TPN-Q123 through TPN-Q126, among others. If your original battery no longer holds a charge or the system runs only on AC, this cell fits the chassis connector and BMS handshake directly.
- SleekBook 14 and 15 platform fit: Both the 14-inch and 15-inch SleekBook variants share the same 14.8V four-cell battery architecture, connector pinout, and BMS communication protocol — one cell covers both chassis without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the SleekBook platform and confirmed the BMS handshake completes correctly, charge current steps down at the expected voltage thresholds, and the cell reaches full capacity without triggering a fault cutoff.
- Post-install calibration on SleekBook: After fitting this cell, run a full discharge until the system hibernates automatically, then charge uninterrupted to 100% without powering on mid-cycle. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on first boot with any new cell.
Why the SleekBook shuts down at 20–30% remaining after a battery swap
The SleekBook's BIOS tracks a learned voltage-to-capacity curve built from the previous cell's chemistry data. A new cell has a different discharge curve, so the BIOS miscalculates the remaining capacity and trips a low-voltage shutdown early — often between 20% and 30% shown on screen. This is not a fault in the replacement cell. Run two full discharge-to-hibernate and charge-to-100% cycles and the fuel gauge IC will recalibrate against the new cell's actual curve. After calibration, the shutdown threshold realigns to the true low-voltage cutoff near 12.0V under load.
BIOS reporting the replacement cell's Wh rating incorrectly in system info
HP's battery EEPROM stores a rated Wh value that the BIOS reads and displays in system diagnostics. When a replacement cell's EEPROM carries a different rated figure than the original, the BIOS will show an unexpected Wh number — sometimes lower, sometimes mismatched entirely. This does not affect actual charge capacity or system operation. To confirm the cell is functioning correctly, check that charge current flows normally and that the battery reaches 16.8V at full charge rather than relying on the BIOS Wh readout.