About this replacement
Sony VAIO Pro 13 — 7.5V Li-Polymer Replacement Battery (VGP-BPS38)
This 7.5V Li-Polymer battery replaces the VGP-BPS38 cell in the Sony VAIO Pro 13 ultrabook. It fits SVP1322YCW, SVP13229PW, SVP13218PW, and over 90 additional Pro 13 variants sharing the same connector and voltage rail. Capacity is 4740mAh (35.55Wh) — matched to the original specification.
- VAIO Pro 13 platform fit: All listed SVP13 models run the same 7.5V two-cell Li-Polymer architecture with identical BMS handshake and flat ribbon connector. The VGP-BPS38, VGP-BPS37, and VGP-BPSE38 part numbers cross-reference to the same physical cell format and EEPROM profile.
- Bench tested on actual hardware: We cycled this cell on a Pro 13 unit and confirmed the BMS accepted the new cell without error flags. Charge termination triggered correctly at 8.4V and the protection circuit tripped cleanly at the low-voltage cutoff threshold.
- First-cycle calibration on the VAIO Pro 13: After installing, run one full discharge until the laptop hibernates, then charge uninterrupted to 100%. This forces the VAIO's fuel gauge IC to recalibrate against the new cell and clears the inaccurate battery health warning that appears after every cell swap.
VAIO Pro 13 shutting down at 20–30% after a battery swap
This is a voltage cliff issue, not a faulty cell. Under combined CPU and display load, the new cell's voltage drops faster than the BIOS fuel gauge expects based on the old cell's discharge curve. The BIOS reads the voltage drop as critically low and triggers an emergency shutdown before the displayed percentage reaches zero. Running two to three full calibration cycles — discharge to hibernate, charge to 100% — lets the fuel gauge IC remap the new cell's actual discharge curve and eliminates the premature shutdown.
BIOS reporting battery health as poor immediately after installation
The VAIO BIOS reads health data from EEPROM registers written by the original cell's charge history. A new cell carries different cycle count and state-of-health values in those registers, which the BIOS flags as degraded. This is a data mismatch — not a physical fault with the replacement cell. To clear it, enter VAIO Care or the battery diagnostics utility and run a full battery learn cycle; the BIOS will rewrite the health registers against the new cell's actual capacity and the warning will not return.