ON-VEHICLE POWER SUPPLY DEVICE AND VEHICLE HAVING ON-VEHICLE POWER SUPPLY DEVICE MOUNTED THEREON

An on-vehicle power supply device according to the present disclosure includes an electricity storage, a charge circuit, a discharge circuit, an input unit, an output unit and a controller. When the controller decides that an emergency operation condition is satisfied, the controllers causes the charge circuit to stop charging power to the electricity storage, then sets an output instruction voltage that is a target voltage value of an output of the discharge circuit to a first voltage value, the controller further causes the discharge circuit to discharge the power charged in the electricity storage, and, when the power output from the discharge circuit becomes higher than a power threshold, the controller lowers an output instruction voltage from a first voltage value to a second voltage value.