Abstract: An electric source noise pattern analysis method for vehicle battery protection and power management and device thereof provides ignition status recognized against battery discharge due to electric equipment requirement. This device is connected in parallel with the main battery and backup battery of a vehicle. This device features the addition of a source characteristic sensing unit which analyzes voltages, currents, power noises of main battery and backup battery, a pattern analysis method which utilizes the sensing characteristics to recognize the running and power used situation of vehicle, and a power management and control unit which employs at least one adjustment timer to manage main battery and backup battery relied on the vehicle situation. The device which operates to connect and disconnect the main and the backup battery from the load based on a sophisticated management algorithm to control to prevent from power exhausted by electric appliances.