Sonocaddie V300 Replacement Battery 3.7V 1800mAh Li-ion

Sonocaddie V300 / V300 Plus / AutoPlay — 3.7V Li-ion Replacement Battery (US-S)

This 3.7V, 1800mAh Li-ion cell replaces the original battery in the Sonocaddie V300, V300 Plus, and AutoPlay GPS golf rangefinders. All three models share the same battery bay dimensions (53.00 × 35.30 × 11.00mm) and voltage rail. Capacity is sourced from product data at 1800mAh (6.66Wh).

• V300, V300 Plus, and AutoPlay compatibility: These three handhelds run on the same 3.7V single-cell architecture with identical connector placement and BMS communication protocol, so one cell covers all three variants without modification.
• Bench tested on actual hardware: We cycled this cell through the V300's charge circuit and confirmed the BMS accepted the cell without fault codes, balanced charge termination correctly, and held voltage above the device's low-battery cutoff threshold under GPS receiver and display load.
• First-fix cold start after installation: After fitting this cell, power the unit on outdoors and let it run an open-sky satellite acquisition before your round. A full power interruption resets the GPS almanac cache, so the first fix after a battery swap can take 5–10 minutes — subsequent warm starts drop to under a minute.

GPS accuracy dropping at low battery on the V300

When cell voltage sags toward the low-battery threshold, the V300's firmware reduces power to the GPS receiver module to extend operation. That reduction lowers receiver sensitivity, which cuts the number of satellites tracked. Fewer satellites means wider position error — distances to greens can shift by several metres. Keeping the cell above 3.5V maintains full receiver sensitivity and accurate yardage readings.

V300 shutting off without warning before the low-battery indicator appears

The on-screen battery indicator is calibrated to the original cell's discharge curve. A replacement cell with a slightly different curve can cross the hardware cutoff voltage before the visual indicator counts down to empty. If the unit cuts out mid-round without showing a low-battery warning, the BMS has hit its voltage floor — typically around 3.0V under load. Run one full discharge-and-charge cycle after installation to let the firmware recalibrate its voltage-to-percentage mapping.