About this replacement
Sony VAIO Tap 11 — 7.5V Li-Polymer Replacement Battery (VGP-BPS39)
This 7.5V, 3860mAh (28.95Wh) lithium-polymer battery replaces the OEM VGP-BPS39 cell in the Sony VAIO Tap 11 hybrid laptop-tablet. It fits the SVT11215CW, SVT11215CGB/W, and SVT11213CGW alongside the base Tap 11 lineup. Voltage, connector pinout, and BMS communication protocol match the original specification.
- SVT11 series fit: All SVT11 Tap 11 variants share the same 7.5V two-cell Li-Polymer configuration and the same 10-pin board connector. The BMS on each model handshakes identically, so one cell covers the entire platform without firmware conflicts.
- Bench tested on actual hardware: We ran the VGP-BPS39 replacement through charge and discharge cycles on an SVT11 board. The BMS accepted the cell without error flags, charge termination triggered correctly at full voltage, and the protection circuit tripped as expected under overcurrent conditions.
- Post-install calibration on the Tap 11: After fitting this cell, run one full discharge until Windows hibernates, 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 SVT11 platform.
BIOS reporting poor battery health immediately after fitting the VGP-BPS39
The SVT11 BIOS stores learned charge data from the previous cell in non-volatile memory. When a new cell goes in, that stored data no longer matches the actual chemistry, so the system flags health as poor or unknown. This is a firmware state issue, not a fault with the replacement cell. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% — after two or three cycles the BIOS recalibrates and the health warning clears.
Tap 11 shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. The percentage readout looks healthy but the actual cell voltage drops below the BMS cutoff threshold under CPU and display load before the gauge catches up. The result is a hard shutdown with charge still showing on screen. Run two full discharge-to-hibernate cycles at normal working load — the fuel gauge IC tracks the new cell's voltage curve and the shutdown point drops back toward the correct low-battery threshold near 3.0V per cell.