About this replacement
HP Omen 15-EK0009TX — 11.55V Li-Polymer Replacement Battery (HSTNN-OB1R)
This is an 11.55V, 4300mAh (49.67Wh) lithium-polymer battery for the HP Omen 15-EK0009TX and compatible Omen and Victus 15 series laptops. It matches OEM part numbers HSTNN-OB1R, L84357-AC1, L84394-005, and SD03XL. Pull the old cell, fit this one, and the system powers on with the correct voltage rail.
- Omen 15-EK and Victus 15-FA series compatibility: These models share the same SD03XL cell format, connector pinout, and BMS communication protocol. The charging circuit and BIOS handshake expect the same 3-cell Li-Polymer pack at 11.55V nominal — this battery meets that spec without any adapter or firmware workaround.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Omen 15-EK platform. The BMS communicated correctly with the BIOS, charge acceptance was normal from 0% to 100%, and no fault codes triggered during high-CPU load draws.
- First-cycle calibration after install: After fitting this battery, run the laptop down to hibernate cutoff, then charge it 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.
BIOS reporting poor battery health immediately after replacement
The Omen's BIOS reads health data from EEPROM registers that the old cell wrote over hundreds of cycles. When a new cell goes in, those registers still carry the previous battery's degraded profile. Windows and BIOS both flag poor health because they're reading stale data, not the new cell's actual state. One full discharge-to-hibernate then uninterrupted charge to 100% forces the fuel gauge IC to rewrite those registers against the new cell. After that cycle, the health warning clears.
Laptop shuts down at 20–30% charge shown on the gauge
This happens when the fuel gauge IC hasn't calibrated against the new cell's actual voltage curve yet. The gauge shows 25% remaining, but the cell voltage under full CPU plus display load drops below the BMS cutoff threshold before the display catches up. The laptop cuts power because the BMS is protecting the cell — the gauge reading is simply wrong at that point. Run two to three full discharge-and-charge cycles without interrupting and the fuel gauge IC will map the new cell's curve accurately.