A voltage control device in one aspect of the present disclosure includes an appliance connector, a voltage output circuit, a manual switch, and a controller. The voltage output circuit outputs an operating voltage based on a direct voltage received from a direct-current power source. In response to a first electric appliance being connected to the appliance connector, the controller controls the voltage output circuit so as to fix the operating voltage. In response to a second electric appliance being connected to the appliance connector, the controller controls the voltage output circuit so as to vary the operating voltage in accordance with a manual operation applied to the manual switch.