A system for setting a shutdown voltage for an electronic device having a power source with an internal resistor includes a temperature sensing module and a processing module. The temperature sensing module is configured for measuring a temperature of the power source, and the temperature sensing module includes a reference resistor with invariable resistance, and generates a reference voltage across the reference resistor based on the temperature of the power source. The processing module is configured for generating a voltage across the internal resistor of the power source based on the temperature of the power source, and setting the shutdown voltage of the electronic device according to the reference voltage and the voltage across the internal resistor.