A power supply device includes converters, a command circuit, and a setter. The converters correspond to loads. The command circuit controls the converters. The setter sets a magnitude of an output of at least one target converter of the converters in accordance with an output characteristic representing a relationship between an input voltage of the at least one target converter and an output limit value which is an upper limit value of the output from the at least one target converter. The output characteristic is a characteristic that the output limit value decreases as the input voltage lowers when the input voltage is lower than a threshold. The setter varies the threshold of the output characteristic in accordance with an operation status of the converters and sets the magnitude of the output from the at least one target converter in accordance with the output characteristic whose threshold has been varied.