A load system includes a power supply input unit for load test of an external power supply, a charging circuit or a charger to which electric power from the power supply is supplied via the power supply input unit, a plurality of loads to which the electric power from the charging circuit or the charger is supplied, and a control circuit that switches selectively and connects the plurality of loads to the charging circuit or the charger. The plurality of loads is a plurality of storage batteries as a load resistance. The control circuit is configured to switch selectively and connect the plurality of storage batteries to the charging circuit or the charger such that the storage battery connected to the charging circuit or the charger among the plurality of storage batteries is charged by the charging circuit or the charger.