Callaway uPro MX+ GPS Replacement Battery 3.7V 750mAh

Callaway uPro MX+ / uPro MX / uPro G1 — 3.7V Li-ion Replacement Battery (8M100003282)

This 3.7V, 750mAh Li-ion cell replaces the original battery in the Callaway uPro MX+, uPro MX, and uPro G1 golf GPS rangefinders. It fits the internal battery bay and connects to the same BMS circuitry as the factory cell. Dimensions are 53.90 × 33.80 × 4.60mm — measure your existing cell before ordering if your unit is a late-revision model.

• uPro MX+ / MX / G1 platform fit: These three models share the same battery footprint, connector pinout, and BMS handshake protocol. One cell covers the full range.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a uPro MX+ unit, confirming BMS acceptance, stable 3.7V nominal output, and correct charge-termination behaviour at full capacity.
• Cold-start satellite acquisition after fitting: After installing this cell, power the device on outdoors before your round begins. The GPS runs a cold start after any full power interruption — first satellite fix takes 5–10 minutes. Subsequent warm starts resolve in under a minute. Plan for this before teeing off.

GPS accuracy dropping at low battery on the uPro MX+

As cell voltage drops toward the BMS low-voltage cutoff threshold, the uPro MX+ reduces power to the GPS receiver to protect remaining charge. Lower receiver sensitivity means the unit locks onto fewer satellites or relies on weaker signals. Yardage readings can drift by several yards under these conditions — enough to matter on an approach shot. Keep the cell above 3.5V during play to maintain full receiver performance.

uPro MX+ shutting off without warning before the battery indicator hits zero

The battery indicator on the uPro MX+ is calibrated to the original cell's discharge curve. A new or aged replacement cell may have a slightly different voltage profile, so the indicator can read one bar remaining while the actual cell voltage is already near the BMS cutoff. The BMS cuts power abruptly at its threshold — typically around 3.0V — with no warning screen. After fitting this cell, run two full charge-discharge cycles so the device firmware can re-calibrate its fuel gauge against the new cell's actual curve.