Globalstar BT-300 GPS Replacement Battery 3.7V 1000mAh

Globalstar BT-300 / BT-308 Bluetooth GPS Receiver — 3.7V Li-ion Replacement Battery

This 3.7V 1000mAh Li-ion cell replaces the original battery in the Globalstar BT-300 and BT-308 Bluetooth GPS receivers. These are compact handheld units used for satellite positioning and tracking in remote field conditions. Capacity is 3.7Wh — matched to the original specification.

• BT-300 and BT-308 platform fit: Both units share the same battery bay dimensions, voltage rail, and connector orientation. The BT-308 added Bluetooth output but kept the same power cell — one replacement covers both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the BT-300 platform. The BMS held cutoff at the correct low-voltage threshold and accepted a full charge without fault flags from the device firmware.
• Cold-start satellite acquisition after swap: After fitting this cell, power the unit on outdoors and let it run until it acquires a full satellite fix before navigating. A full power interruption forces a cold start — first fix after a swap takes 5 to 10 minutes, compared to under a minute on a warm start once the almanac is rebuilt.

GPS accuracy reduced at low battery on the BT-300

When cell voltage drops below roughly 3.5V, the BT-300 reduces RF receiver sensitivity to protect remaining charge. This shows up as position drift or a weaker satellite signal count — not a firmware error. The receiver is deliberately throttling its draw. Keeping the cell above that threshold restores full signal acquisition performance.

Device shuts off without low-battery warning

The BT-300 battery indicator is calibrated to the original cell's discharge curve. A new cell — or one the unit hasn't profiled yet — can cause the indicator to read inaccurately for the first few cycles. The device hits its hardware voltage cutoff at 3.2V before the software indicator reaches the final warning bar. Run two or three full charge-to-cutoff cycles and the indicator will recalibrate to the new cell's curve.