Holux GR-230 GPS Replacement Battery 3.7V 900mAh

Holux GR-230 / GR-231 GPS Receiver — 3.7V Li-ion Replacement Battery

This is a 3.7V, 900mAh Li-ion cell built to fit the Holux GR-230 and GR-231 portable GPS receivers. Both models share the same battery bay dimensions and voltage rail, so one cell covers either unit. Capacity matches the original spec at 900mAh (3.33Wh).

• GR-230 and GR-231 compatibility: Both receivers use the same 52.90 × 32.50 × 7.50mm cell with an identical 3.7V nominal rail and matching connector orientation. The BMS in each unit reads the same charge profile, so no handshake issues occur on first boot.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the GR-230 platform. The onboard BMS accepted the charge curve without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• First fix after a battery swap: After fitting a fresh cell, power the unit on outdoors in clear sky view and let it run a full cold start. The GR-230 has no cached almanac data after a full power removal, so the first satellite fix takes 5–10 minutes. Subsequent warm starts drop back under a minute once the almanac rebuilds.

GPS accuracy dropping as the GR-230 battery runs low

At low charge states, the GR-230 reduces RF receiver sensitivity to keep the processor running longer. This shows up as fewer satellites tracked and wider position scatter on the map. The receiver may still display a fix, but the HDOP value climbs and reported accuracy degrades. Keep the cell above the low-battery indicator to hold full receiver sensitivity — once the icon appears, recharge before relying on the position readout for navigation decisions.

GR-230 shutting off without a low-battery warning

The fuel gauge on the GR-230 calibrates against the original cell's discharge curve. A new cell — or an aged one with shifted internal resistance — can hit the hardware voltage cutoff before the on-screen indicator reaches the last bar. The result is an abrupt shutdown with no visible warning. Run two or three full charge-discharge cycles after fitting this replacement to let the gauge re-calibrate. After recalibration, the warning should appear at approximately 3.55V, giving you enough time to save position data before shutdown.