About this replacement
HP ProBook 450 G6 — 11.55V Li-Polymer Replacement Battery (RE03XL)
This is an 11.55V, 3800mAh (43.89Wh) Li-Polymer replacement battery for the HP ProBook 450 G6, 440 G6, 430 G6, and 445 G6. It uses OEM part number RE03XL and cross-references HSTNN-DB9A, L32407-2B1, and L32656-005 among others. If the original cell is swollen, dead, or no longer holding charge, this is the direct cell swap.
- ProBook 430 / 440 / 445 / 450 G6 platform fit: These four models share the same 11.55V three-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol — one cell covers all four. The BIOS on each expects the same EEPROM battery ID, so the RE03XL registers correctly without firmware flags on any of them.
- Bench tested on actual hardware: We ran this cell in a ProBook 450 G6 and confirmed the BMS handshake completed on first insertion, the BIOS accepted the cell as a known battery, and charge current stepped correctly from bulk to taper phase without interruption or error codes.
- BIOS learn cycle after swap: After installing, discharge the laptop fully until it hibernates on its own, then charge uninterrupted to 100% without waking it. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on the first few boots after any cell replacement.
Why the ProBook 450 G6 reports poor battery health after a cell swap
The HP BIOS stores charge history and wear data in the old cell's EEPROM. When a new cell goes in, that history resets to zero, and the BIOS interprets the mismatch as a degraded or unknown battery. The health warning is a firmware artefact — not a sign the replacement cell is faulty. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% lets the BIOS rebuild its learn table against the new cell and clears the warning.
ProBook 450 G6 shutting down at 20–30% charge remaining
This happens when the fuel gauge IC inside the laptop is still calibrated to the old cell's voltage curve. The IC reads 20–25% but the actual cell voltage has already hit the low-cutoff threshold under full CPU and display load — so the system cuts out without warning. The fix is a calibration cycle: let the laptop run unplugged on battery-only until it hibernates at low battery, then charge to 100% without interruption. After two to three of these cycles, the fuel gauge re-anchors to the new cell and the shutdowns stop.