1. A power conversion apparatus comprising:an inverter that converts a DC voltage supplied from a battery into an AC voltage;
a DC-to-DC converter that steps up or down the DC voltage supplied from the battery; and
a case that includes a plurality of walls surrounding the inverter, an inverter input terminal to which a power line from the battery is connected so as to input the DC voltage to the inverter, and a converter input terminal to which a power line connecting to the DC-to-DC converter is connected so as to input the DC voltage to the DC-to-DC converter, wherein
the plurality of walls includes a reference wall and an opposed wall that is opposed to the reference wall,
the inverter input terminal is disposed adjacent to the reference wall with respect to an imaginary plane that bisects the case between the reference wall and the opposed wall, and
the converter input terminal is disposed adjacent to the opposed wall with respect to the imaginary plane.