HP Chromebook X360 12B Compatible Battery HSTNN-LB8P 7.7V

HP Chromebook X360 12B Series — 7.7V Li-Polymer Replacement Battery (HSTNN-LB8P)

This is a 7.7V, 4950mAh (38.12Wh) Li-Polymer battery for the HP Chromebook X360 12B-CA series 2-in-1 convertible. It replaces OEM part numbers HSTNN-LB8P, L63999-421, L64430-005, and MD02XL. Fits the 12B-CA0000NG, 12B-CA0000NS, 12B-CA0000UR, 12B-CA0001NA, and over a dozen additional X360 12B variants.

• X360 12B platform fit: All 12B-CA variants share the same 7.7V two-cell Li-Polymer configuration, flat-pack form factor, and BMS connector pinout. The HSTNN-LB8P part number covers the full sub-series because HP used one battery assembly across the entire 12B-CA production run.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a 12B-CA unit, monitoring BMS communication at each stage. The protection circuit tripped correctly at low-voltage cutoff and handed control back to the system without error on charge resumption.
• Post-install calibration on the X360 12B: After fitting, run the battery down until the Chromebook hibernates, then charge uninterrupted to 100% without waking the device. This lets the BIOS complete its battery learn cycle against the new cell and clears the inaccurate health warning that appears after every cell swap.

BIOS reporting poor battery health immediately after swapping the X360 12B cell

When the Chromebook's BIOS reads health data, it pulls cycle count and wear metrics stored in the old cell's EEPROM. A new cell arrives with a different EEPROM state, so the BIOS flags it as degraded before it has run a single cycle. This is a firmware interpretation issue, not a fault with the replacement cell. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% lets the BIOS rewrite its learned capacity baseline against the new cell. After that cycle, the health indicator should clear to normal.

Chromebook X360 12B shutting off at 20–30% charge shown on screen

The fuel gauge IC calibrates its charge estimate against the cell's actual voltage curve. If a new cell's curve differs slightly from the stored model, the gauge reports capacity remaining while the real cell voltage has already dropped below the BMS cutoff threshold. Under combined CPU and display load — common in tent or tablet mode — the draw spikes, voltage collapses faster than the gauge tracks, and the system cuts off. Complete two to three full discharge-to-hibernate and full-charge cycles to let the fuel gauge IC re-map against the actual cell. After calibration, the shutdown threshold should stabilise at or below 5% as shown.