Power supply system

A power supply system that supplies power to a load, the system comprising:

• a high-potential end to which a positive voltage is applied from a DC power source;
• a low-potential end that outputs the power along with the high-potential end;
• a power storage element including a positive terminal and a negative terminal, the negative terminal being connected to the low-potential end;
• a diode including an anode and a cathode, the cathode being connected to the high-potential end;
• a power source line connected between the anode and the positive terminal;
• and
• a first switch, connected in parallel, to the diode, the first switch turning on when the power storage element is to be charged from the DC power source through the high-potential end or when a current value of discharge current flowing in the power source line from the positive terminal toward the anode is greater than, or equal to a positive threshold, and the first switch turning off when the power storage element is not to be charged and the current value is less than the threshold.