HP Elite Folio 13.5 2-in-1 HSTNN-OB1U Replacement Battery 7.7V

HP Elite Folio 13.5 inch 2-in-1 — 7.7V Li-Polymer Replacement Battery (HSTNN-OB1U)

This 7.7V, 6150mAh lithium-polymer battery replaces the original cell in the HP Elite Folio 13.5 inch 2-in-1 convertible. It fits across OEM part numbers HSTNN-OB1U, M07389-AC1, M07392-005, MA04046XL, and MA04XL. Capacity is rated at 47.36Wh, matching the original specification for this device.

• Elite Folio 13.5 2-in-1 compatibility: All five OEM part numbers listed above share the same 7.7V voltage rail, connector pinout, and BMS handshake protocol. The Elite Folio uses a single battery configuration regardless of whether the unit was sold in laptop or tablet orientation mode — one cell covers both use cases.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Elite Folio platform. The BMS handshake completed without fault codes, and the charge controller accepted the cell without triggering a protection cutoff or unknown-device flag.
• Post-install calibration on the Elite Folio: After fitting this cell, run the battery down to the point where the system hibernates, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that nearly every replacement cell triggers on first boot.

BIOS reporting poor battery health immediately after replacement

The Elite Folio's BIOS reads health data from the EEPROM embedded in the old cell. When a new cell goes in, that EEPROM data does not transfer — the BIOS has no prior cycle history to reference, so it flags the battery as degraded or unknown. This is a firmware read issue, not a fault with the replacement cell. Running one full discharge-to-hibernate followed by a full uninterrupted charge gives the BIOS enough data to rewrite its internal battery learn table. After one to three cycles, the health indicator updates to reflect actual cell condition.

Laptop shutting down with 20–30% charge still showing on screen

This happens when the fuel gauge IC calibration has not yet aligned to the new cell's discharge curve. The original cell and the replacement do not have identical internal resistance profiles, so the fuel gauge misjudges the voltage cliff — it reads 25% remaining but the cell is already at a voltage the BMS treats as cutoff under load. The fix is to complete two to three full discharge and charge cycles without interruption. After calibration cycles complete, the reported percentage at shutdown should stabilise above 5%, confirming the fuel gauge IC is tracking the correct curve for this cell.