About this replacement
Sony VAIO VPC-SB11FX/B Series — 11.1V Li-Polymer Replacement Battery (VGP-BPS24)
This is an 11.1V, 4400mAh (48.84Wh) lithium-polymer battery built to fit the Sony VAIO VPC-SB Series ultraportable notebooks. It replaces OEM part numbers VGP-BPS24 and VGP-BPL24. The physical connector, cell orientation, and BMS pin layout match the original battery tray exactly.
- VAIO VPC-SB Series compatibility: These models share a common 11.1V three-cell Li-Polymer architecture with the same bottom-contact connector and identical BMS handshake protocol. A single replacement cell covers the full VPC-SB11 range without modification.
- Bench tested on actual hardware: We ran this cell on a VPC-SB unit and confirmed the BMS handshake completed within two minutes of installation. The BIOS recognised the battery, charge initiation started automatically, and the fuel gauge IC began tracking state-of-charge from first contact.
- Post-install calibration on the VAIO VPC-SB: After fitting this cell, 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 after every cell swap on the VPC-SB platform.
BIOS reporting battery health as poor immediately after replacement
The VPC-SB BIOS stores health data from the previous cell in its EEPROM. When a new battery is installed, the BIOS compares live cell data against that stored profile and flags a mismatch as poor health. This is not a fault with the replacement cell — it is a firmware artefact. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the BIOS learn cycle to overwrite the old EEPROM values with data from the new cell, clearing the warning.
Laptop shuts down abruptly at 20–30% charge shown on screen
This is a voltage cliff failure — under combined CPU and display load, the cell voltage drops faster than the fuel gauge IC anticipates, triggering an emergency shutdown before the displayed percentage reaches zero. It typically appears when the fuel gauge IC has not yet calibrated against the new cell's discharge curve. Run two full discharge-and-charge cycles without interruption to allow the IC to map the actual voltage-to-capacity relationship of the new cell. After calibration, the shutdown threshold should align with a displayed level below 5%.