Sony SP60BPRA9C Bluetooth Laser Mouse Compatible Battery 3.7V 660mAh

Sony VGP-BMS77 Bluetooth Laser Mouse — 3.7V Li-ion Replacement Battery (SP60BPRA9C)

This 3.7V, 660mAh Li-ion cell replaces the internal rechargeable battery in the Sony VGP-BMS77 Bluetooth Laser Mouse. It fits the SP60BPRA9C, SP60, and 4-268-590-02 OEM references. When the original cell no longer holds a charge, this direct swap restores wireless operation and laser tracking.

• VGP-BMS77 platform fit: The VGP-BMS77 uses a slim single-cell Li-ion pack at 3.7V nominal. The SP60BPRA9C form factor — 40.00 × 31.10 × 5.90mm — matches the internal bay exactly, and the BMS handshake aligns with Sony's charge management circuit for this mouse.
• Bench tested on actual hardware: We cycled this cell through the VGP-BMS77's charge circuit and confirmed the BMS accepted the cell without fault flags. Voltage at full charge reached 4.18V, and the protection circuit tripped correctly at the low-voltage threshold before the cell could be damaged.
• Post-swap Bluetooth reconnection: After fitting a new cell in this mouse, Bluetooth does not always reconnect automatically. Hold the pairing button on the underside of the mouse for five seconds to force the device to re-advertise to the host before assuming the battery is faulty.

Why the VGP-BMS77 pointer stutters before the battery reads empty

The VGP-BMS77 reduces its Bluetooth polling rate when cell voltage drops below roughly 3.5V — a power-saving behaviour baked into Sony's firmware. This shows up as lag or skipping cursor movement while the battery indicator still shows partial charge. The reported charge level lags behind actual cell voltage because the fuel gauge averages readings over time. If the pointer is stuttering, treat it as an end-of-life signal and replace the cell.

Mouse not reconnecting to the host after battery replacement

A full power loss clears the active Bluetooth session on the VGP-BMS77 — the host computer and mouse both drop the pairing state. Replugging the USB Bluetooth receiver or toggling Bluetooth off and on at the host resets the host-side session. Then hold the pairing button on the base of the mouse for five seconds until the LED blinks rapidly. Reconnection should complete within 30 seconds; if not, check that cell voltage is above 3.6V before assuming a pairing fault.