A low power DC-DC converter (LDC) control circuit is provided and includes a detector, a storage, and an LDC. The detector detects an output voltage of the LDC and characteristic factors in a vehicle. The storage receives the characteristic factors and cumulatively stores the characteristic factors. The LDC controller initializes the characteristic factors cumulatively stored in the storage when a state of charge (SOC) of a battery of the vehicle is maintained to a preset value for a preset time while the LDC output voltage is maintained to be the same as in a refresh operation.