1. A charging device that is mounted on an electrified vehicle, the charging device comprising: a first charger configured to convert alternating current power supplied from outside to direct current power to be supplied to a battery of the electrified vehicle;

a second charger configured to convert the alternating current power supplied from the outside to the direct current power to be supplied to the battery, and configured to convert direct current power supplied from the battery to alternating current power to be supplied to the outside;

a direct current-to-direct current converter configured to convert the direct current power supplied from the battery to low voltage direct current power to be supplied to an auxiliary battery of the electrified vehicle;

a relay configured to electrically connect and disconnect a direct current charging inlet of the electrified vehicle to and from the battery; and

a housing including a first chamber that houses the second charger, a second chamber that houses the first charger and the relay, and a third chamber that houses the direct current-to-direct current converter, wherein

a first cooling medium channel configured to cool the second charger and a second cooling medium channel configured to cool the direct current-to-direct current converter are provided in the housing,

the first charger and the relay are cooled by a common cooling medium channel provided in the housing,

the first chamber is located above the second chamber,

the second chamber is located above the third chamber,

the second charger is attached to an upper surface of the first chamber,

the first cooling medium channel is provided in an upper wall of the housing that forms the upper surface of the first chamber,

the first charger and the relay are attached to a lower surface of the second chamber,

the direct current-to-direct current converter is attached to an upper surface of the third chamber, and

the second cooling medium channel is provided in a partition wall of the housing that forms the lower surface of the second chamber and the upper surface of the third chamber.