About this replacement
HP Pavilion 15-AC154NG — 10.95V Li-ion Replacement Battery (807611-121)
This is a 10.95V, 2600mAh (28.47Wh) lithium-ion replacement battery for the HP Pavilion 15-AC154NG and a wide range of Pavilion 15 and 17 series notebooks. It covers OEM part numbers including HS03, HS04, HSTNN-LB6U, and 807956-001, among others. If your original pack no longer holds a charge or the laptop runs only on AC power, this cell fits the same connector and BMS interface.
- Pavilion 15/17 series compatibility: HP used the same 10.95V three-cell architecture and HS03/HS04 BMS handshake across multiple Pavilion 15-AC, 15-AY, and 17-X sublines. The connector pinout, voltage rail, and communication protocol are identical across this generation, so one cell covers all of them.
- Bench tested on actual hardware: We cycled this cell on a Pavilion 15-AC unit and confirmed the BMS initialised correctly, charge current ramped normally through CC/CV stages, and the pack hit full termination voltage without fault codes.
- Post-install discharge cycle on Pavilion notebooks: After fitting, run the laptop on battery until it hibernates at near-zero, then charge uninterrupted to 100%. This forces the HP BIOS to complete its battery learn cycle. Skipping this step often leaves the fuel gauge reporting inaccurate percentages or a false "poor health" warning for the first several sessions.
BIOS reporting poor battery health immediately after a cell swap
HP's BIOS reads health data stored in the pack's EEPROM and compares it against learned charge history from the previous cell. A fresh replacement has no history, so the BIOS flags it as degraded until it accumulates real cycle data. This is not a fault with the new cell — it is a calibration gap. Run two full discharge-to-hibernate and full-recharge cycles. After that, the health indicator in HP Support Assistant updates to reflect actual capacity.
Laptop shuts off at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated to the new cell's discharge curve. The percentage reading is based on old voltage-to-capacity mappings, so the displayed figure and the actual cell voltage diverge under load. When the CPU and display draw full current, the cell voltage drops below the BMS cutoff threshold before the gauge reaches zero. Run a full uninterrupted discharge until the unit hibernates, then charge to 100% — the gauge IC resets its reference point and the shutoff behaviour corrects from that cycle onward.