Milink GPSL-149 Compatible Battery 3.7V 180mAh Li-Polymer

Milink GPSL-149 — 3.7V Li-Polymer Replacement Battery

This 3.7V, 180mAh lithium-polymer cell replaces the original battery in the Milink GPSL-149 portable GPS navigator. At 30 x 20 x 4mm, it fits the compact housing without modification. Capacity figures come from the product specification — 180mAh / 0.67Wh.

• GPSL-149 fit: The GPSL-149 uses a small Li-Polymer pouch cell running a single 3.7V rail. This cell matches that voltage, footprint, and connector orientation so the BMS handshake completes on first boot.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS accepted the cell without a fault code, held charge termination at 4.2V, and cut off cleanly at the low-voltage threshold without tripping a protection error.
• Cold-start satellite acquisition after swap: After fitting this cell, power the GPSL-149 on outdoors and let it run until it acquires a satellite fix before packing it away. Full power removal clears the GPS receiver's warm-start cache, so the first fix after a battery swap takes 5–10 minutes rather than under a minute for subsequent sessions.

GPS accuracy reduced at low battery on the GPSL-149

When cell voltage drops toward 3.5V, the GPSL-149 reduces RF receiver sensitivity to protect the remaining charge. This lowers the number of satellites the unit can track simultaneously. Position accuracy degrades as a result — not a GPS signal problem, a power-management decision made by the firmware. Keeping the cell above 3.6V under load maintains full receiver performance.

GPSL-149 shutting off without a low-battery warning

The battery indicator on the GPSL-149 reads state-of-charge from a voltage curve calibrated to the original cell. A new or degraded cell with a slightly different discharge curve can make the indicator read 20–30% remaining right up until the cutoff threshold is hit. The device shuts off abruptly with no warning bar showing empty. Charge the unit fully to 4.2V and run two full discharge cycles to allow the firmware to recalibrate the indicator against the new cell's curve.