A charging device of an aspect of the present disclosure includes couplers and control circuitry that controls a charging operation. If the number of one or more secondary battery-equipped devices to be charged is smaller than a set number, the control circuitry charges each of the one or more secondary battery-equipped devices to be charged with a continuous current. If the number is greater than or equal to the set number, the control circuitry intermittently repeats charging of each of the one or more secondary battery-equipped devices to be charged with a stopping interval placed between charging operations while selectively and sequentially switching the one or more secondary battery-equipped devices to which a charging current is supplied at the same time, and the control circuitry increases the charging current and shortens an application duration of the charging current per charging with an increase in the number of secondary battery-equipped devices to be charged.