Control method for vehicle mounted GPS terminal two times lowering electricity

The present invention discloses a secondary power supply control method for vehicle-mounted GPS terminals, which includes processing procedures below: 1) A power supply device of an vehicle battery for a vehicle-mounted GPS terminal is divided into two branches respectively to supply electric power to a main load and an auxiliary load of the vehicle-mounted GPS terminal; 2) As the vehicle-mounted GPS terminal detects that vehicle power-off exceeds a specific time, the present invention cuts off the vehicle battery and rejects power supply for the auxiliary load; (3) As the vehicle-mounted GPS terminal finds out voltage of the vehicle battery is lower than a lower limit of a set power supply voltage, power supply of the vehicle battery to the main load and the auxiliary load is cut off. The present invention can reduce power consumption by cutting off the main load while vehicles berthing for long, thus increasing service life of the vehicle battery. As the power supply voltage of the vehicle battery is worsen