About this replacement
HP Pavilion 500 / 520 Series — 14.4V Li-ion Replacement Battery (434045-141)
This is a 14.4V, 2200mAh (31.68Wh) Li-ion battery for the HP Pavilion dv5-500 and dv5-520 notebook series. It replaces OEM part numbers including 434045-141, 438518-001, HSTNN-IB39, and HSTNN-FB39. If the original cell no longer holds a charge or the laptop drops off abruptly under load, this is the direct swap.
- 500 and 520 series compatibility: Both model lines share the same 14.4V battery rail, connector pinout, and BMS handshake protocol. The EEPROM on this cell carries the correct identification data so the HP EC recognises it without triggering an unknown-battery error on boot.
- Bench tested on actual hardware: We cycled this cell through full charge and load discharge on the dv5-520 platform. The BMS held protection thresholds correctly, and the EC registered accurate state-of-charge data from the first complete cycle.
- First-cycle conditioning on HP Pavilion: After installing, run a full discharge to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on the first boot after every cell swap.
Why the dv5-500 shuts down at 20–30% remaining after a battery swap
The HP Pavilion EC uses stored voltage-curve data from the old cell to predict remaining charge. When a new cell goes in, that stored map is stale. Under full CPU plus display load, the new cell hits a voltage cliff the EC wasn't expecting, and it triggers an immediate shutdown to protect the board. This is not a fault with the replacement battery. One full discharge-to-hibernate followed by an uninterrupted charge to 100% gives the EC enough real data to rebuild an accurate curve. After two to three full cycles, the shutdowns stop.
BIOS reporting 0% or "unknown" battery immediately after installation
The HP EC reads battery identity and state-of-charge from the cell's EEPROM before displaying anything in BIOS or Windows. If the EEPROM handshake doesn't complete on first connect — often because the contact pads weren't fully seated — the EC returns a zero or unknown value. Re-seat the battery, ensure the latch clicks, then do a hard reset: remove the cell, hold the power button for 15 seconds with no power connected, reinsert, and boot. If the BIOS still shows 0%, boot into Windows and let the battery learn cycle run at least once before drawing conclusions. The target after a full charge is 14.4V at the terminals.