Typhoon MyGuide 3100 GPS Replacement Battery 3.7V 1100mAh

Typhoon MyGuide 3100 — 3.7V Li-Polymer Replacement Battery (BT553759)

This 3.7V, 1100mAh Li-Polymer cell replaces the BT553759 battery in the Typhoon MyGuide 3100 portable GPS navigator. It matches the original cell's dimensions at 58.70 x 35.95 x 4.96mm, so it seats correctly in the battery bay without modification. Voltage and capacity are sourced from the OEM spec — 4.07Wh total energy.

• MyGuide 3100 fitment: The BT553759 is specific to this navigator's form factor. The connector orientation and cell thickness are matched to the original housing dimensions, so the rear cover closes flush without pressure on the cell.
• Bench tested on actual hardware: We cycled this cell through charge and discharge under GPS-active load conditions. The BMS held the charge curve stable and cut off cleanly at the low-voltage threshold without false shutdowns.
• Cold-start preparation after fitting: After installing this cell, power the unit on outdoors with a clear sky view and let it run until it acquires a satellite fix. The GPS performs a full cold start after any complete power interruption — first fix can take 5–10 minutes; subsequent warm starts drop to under a minute once almanac data is cached.

GPS accuracy reduced at low battery on the MyGuide 3100

The MyGuide 3100's receiver draws more power during active satellite tracking than during standby. At low cell voltage, the unit can throttle receiver sensitivity to reduce draw — this shows up as position drift or a weaker signal bar reading even with clear sky overhead. It is not a hardware fault with the antenna. Keeping the cell above 3.5V during navigation holds the receiver at full sensitivity.

MyGuide 3100 shuts off without warning during navigation

This happens when the battery indicator is no longer calibrated to the actual cell — the on-screen gauge still shows one or two bars, but the cell voltage has already dropped below the BMS cutoff threshold. The BMS protects the cell by cutting power abruptly at around 3.0V rather than allowing a damaging deep discharge. After fitting a new cell, run two full charge and discharge cycles during active navigation to let the device recalibrate its voltage-to-percentage mapping. The shutdowns should stop once the indicator tracks the real cell curve.