About this replacement
HP ProBook 450 G8 / 650 G8 / 430 G8 — 11.4V Li-Polymer Replacement Battery (RH03XL)
This is an 11.4V, 3850mAh (43.89Wh) Li-Polymer replacement battery for the HP ProBook 450 G8, 650 G8, and 430 G8 series notebooks. It fits using OEM part numbers RH03XL, HSTNN-IB9P, HSTNN-OB1T, and M01524-171, among others. It restores full portable operation when the original cell has degraded or failed.
- ProBook 4x0/650 G8 platform fit: These three notebook lines share the same 11.4V three-cell Li-Polymer architecture, connector pinout, and BMS communication protocol — which is why a single part number covers all of them. The fuel gauge IC talks to HP's BIOS over the SMBus using the same EEPROM register map across the range.
- Bench tested on actual hardware: We ran this cell in a ProBook 450 G8 and confirmed the BMS handshake completed correctly, charge accepted through all three charge stages, and the SMBus reported state-of-charge without errors. No thermal events occurred across three full charge-discharge cycles.
- First-cycle calibration after install: After fitting this battery, run the laptop down to hibernate cutoff on normal workload — do not force shutdown — then charge uninterrupted to 100%. This forces the HP fuel gauge IC to re-learn the new cell's capacity curve and clears the inaccurate health warning that appears in HP Support Assistant after every cell swap.
BIOS reporting battery health as poor immediately after replacement
HP's BIOS reads health data from the battery's EEPROM on first boot. When a new cell arrives, the EEPROM cycle count is at zero and the full-charge capacity figure does not yet match the BIOS's learned value from the old cell — so it flags the battery as unknown or poor. This is not a fault with the replacement unit. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100%, and the BIOS battery learn cycle will update the stored capacity data. After one or two calibration cycles, HP Support Assistant should report normal health status.
Laptop shutting down at 20–30% charge shown on screen
This symptom means the fuel gauge IC's charge map is out of sync with the new cell's actual voltage curve. The gauge reports 20–30% remaining, but the cell voltage has already dropped below the BMS cutoff threshold under combined CPU and display load — so the system shuts off hard. It is a calibration gap, not a defective battery. Force a full discharge to hibernate (not sleep — hibernate) so the BMS logs the true empty voltage, then charge to 100% without interruption. After two full cycles the gauge should track accurately and the premature shutdowns will stop.