HP 412789-001 Replacement Battery 10.8V 4400mAh

HP EliteBook 2530p / 2533t / 2540p — 10.8V Li-ion Replacement Battery (412789-001)

This 10.8V, 4400mAh (47.52Wh) Li-ion battery replaces the original cell in the HP EliteBook 2530p, EliteBook 2533t, EliteBook 2540p, and 2533t. It matches the OEM voltage rail and connector pinout for these ultraportable business notebooks. Cross-references include BJ803AA, HSTNN-XB21, HSTNN-XB22, HSTNN-XB23, and MS06XL.

• EliteBook 2530p / 2533t / 2540p compatibility: These three models share the same battery bay dimensions, 10.8V three-cell voltage rail, and six-pin SMBus connector. The BMS on each communicates charge state over the same protocol, so one cell fits all three without adapter or modification.
• Bench tested on actual hardware: We ran this cell on a 2530p and 2540p chassis. The BMS handshake completed on first insertion, charge accepted immediately through the standard CC/CV cycle, and no thermal flags triggered during load testing at full CPU and display draw.
• Post-install calibration on the EliteBook platform: After fitting this cell, run a full discharge to hibernate cutoff, then charge uninterrupted to 100% without powering on mid-cycle. This forces the BIOS battery learn cycle to reset against the new cell chemistry and clears the false "poor health" warning that appears after every cell swap on these notebooks.

BIOS reporting poor battery health immediately after fitting a new cell

The EliteBook BIOS stores learned capacity data from the old cell in EEPROM. When a new cell goes in, that stored data no longer matches actual cell behaviour, so the BIOS flags health as poor or unknown before it has run a single charge cycle. This is not a fault with the replacement cell — it is a calibration state. One full discharge-to-hibernate followed by an uninterrupted charge to 100% rewrites the EEPROM baseline. After two or three cycles the health indicator reads accurately.

Laptop shutting down abruptly at 20–30% charge shown on screen

This happens when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. The gauge reports 25% remaining, but the cell voltage has already dropped below the BMS cutoff threshold under combined CPU and display load. The system shuts down to protect against over-discharge, even though the screen shows charge left. Run two full discharge-to-hibernate cycles and the fuel gauge IC will map the new cell's voltage cliff correctly — after that, shutdown aligns with the percentage shown.