SkyGolf SG1 GPS Replacement Battery 3.7V 1350mAh

SkyGolf SG1 / SG2 Series — 3.7V Li-Polymer Replacement Battery (GP50301HG026)

This 3.7V, 1350mAh Li-Polymer cell replaces the original battery in the SkyGolf SG1, SG2, SG2-USB, and SG0003 handheld golf GPS navigators. It matches the OEM part number GP50301HG026 and fits the same 50.81 × 34.28 × 7.81 mm footprint. When the original cell degrades and the device stops holding a charge through a round, this swap restores full GPS and display operation.

• SG1, SG2, SG2-USB, and SG0003 compatibility: These models share the same battery bay dimensions, connector pinout, and 3.7V supply rail, so one cell covers the full lineup without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SG1 platform, confirmed BMS cutoff at the correct low-voltage threshold, and verified the GPS module received stable voltage through a full satellite acquisition sequence.
• First-fix satellite acquisition after fitting: After fitting this cell, power the SG1 fully on outdoors and let it run a cold-start satellite acquisition before you head to the first tee. A cold start — triggered by any full power interruption — can take 5–10 minutes for the initial fix. Subsequent warm starts drop to under a minute once the device has cached its almanac data.

GPS accuracy dropping as the SG1 battery runs low

The SG1's GPS receiver draws the most current of any subsystem in the device. At low battery voltage, the firmware reduces receiver sensitivity to stay within power budget, which can increase positional error — particularly under tree cover or in valleys where signal strength is already marginal. Keeping the cell charged above 3.5V maintains full receiver gain. If you notice distance readings jumping or satellite count dropping late in a round, that's the sensitivity reduction kicking in, not a faulty antenna.

SG1 shutting off without a low-battery warning

After a battery swap, the SG1's fuel gauge is uncalibrated — it hasn't yet mapped the new cell's discharge curve. The device may show two or three bars of charge and then cut off with no warning when voltage drops past the BMS protection threshold. This resolves itself after one or two full charge-to-discharge cycles, which allows the gauge to recalibrate to the new cell's actual capacity. Run the first cycle by charging to 100% via USB and using the device until it powers off on its own — don't interrupt mid-cycle.