Magellan RoadMate 1200 Replacement Battery 3.7V 1100mAh

Magellan RoadMate 1200 / 1210 Series — 3.7V Li-ion Replacement Battery (384.00015.005)

This 3.7V 1100mAh (4.07Wh) lithium-ion cell replaces the original battery in the Magellan RoadMate 1200 and RoadMate 1210 portable GPS navigators — specifically the 3-wire connector variants. It matches the OEM part number 384.00015.005 and fits the 53.934 × 34.27 × 5.70mm battery cavity.

• RoadMate 1200 and 1210 (3-wire) compatibility: Both models use the same 3-wire connector and BMS handshake — the third wire carries thermistor data to the charge controller. This cell includes that thermistor line. A 2-wire cell will not charge correctly in these units.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a RoadMate 1200 chassis. The BMS accepted the handshake without fault codes, and the charge controller reached full termination voltage at 4.2V as expected.
• First satellite fix after fitting: After any full power interruption, the RoadMate 1200 performs a cold start. Power the unit on outdoors and leave it stationary — first satellite acquisition takes 5 to 10 minutes. Subsequent warm starts run under a minute once ephemeris data is cached.

GPS accuracy reduced at low battery on the RoadMate 1200

When the RoadMate 1200 battery drops below roughly 3.5V, the unit begins reducing GPS receiver sensitivity to conserve power. This shows up as position drift or longer re-acquisition times — the GPS signal icon may still appear, but fix accuracy degrades. It is not a hardware fault. Keeping the cell above 3.6V during active navigation prevents the unit from entering this reduced-sensitivity mode.

RoadMate 1200 shuts off without a low-battery warning

After a battery swap, the fuel gauge IC inside the RoadMate 1200 loses its calibration data — it no longer knows the cell's true state of charge. The unit tracks voltage instead, and if the on-screen indicator is out of step with actual voltage, the device hits the hardware cutoff threshold before any warning appears. Run two full charge-discharge cycles after fitting this cell. That re-exposes the fuel gauge to the real voltage curve and restores accurate low-battery warnings.