Garmin Approach G80 Replacement Battery 3.8V 1900mAh

Garmin Approach G80 — 3.8V Li-Polymer Replacement Battery (361-00124-00)

This is a 3.8V 1900mAh Li-Polymer cell built to the same specification as the factory battery in the Garmin Approach G80 handheld GPS golf navigator. It fits the G80 directly and restores full function to units where the original cell no longer holds charge. Capacity is 1900mAh (7.22Wh), matching the OEM figure.

• Approach G80 fit: The G80 uses a flat Li-Polymer pouch cell at 3.8V nominal with a specific three-pin connector. The BMS on this device monitors cell voltage and temperature. Any cell that deviates from the correct voltage rail causes the device to refuse to power on entirely.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the G80 platform. The BMS accepted the cell without fault codes, charged to full without interruption, and the GPS module initialised normally on power-up.
• Cold-start satellite acquisition after swap: After fitting this battery, power the G80 on outdoors before your round and let it run a full satellite acquisition. A cold start after total power removal takes 5–10 minutes for first fix. Subsequent warm starts drop back under a minute once almanac data is cached.

GPS accuracy dropping as the Approach G80 battery depletes

The G80 reduces power to the GPS receiver module when cell voltage falls below a certain threshold. This shows up as position drift or slower course map updates — not a software glitch, but a deliberate low-power state. A fresh cell running at full nominal voltage keeps the receiver at full sensitivity for the entire round. If accuracy issues appear mid-round, check that the battery registers above 3.5V under load.

Approach G80 shutting off without low-battery warning

After a battery swap, the G80's fuel gauge IC has not yet profiled the new cell. It reads state-of-charge from a model calibrated to a depleted original battery, which means the on-screen indicator can show two bars and the device still cuts off. This is not a faulty battery — it is an uncalibrated gauge. Run two full charge-discharge cycles in normal use and the gauge will re-anchor its low-voltage cutoff threshold accurately.