A charger according to one aspect of the present disclosure includes a current outputter, a first charge controller, and a second charge controller. The first charge controller receives a first required information from a first device in accordance with a first communication protocol. The first communication protocol requires at least a first minimum volume of communication to acquire the first required information from the first device. The second charge controller receives a second required information from a second device in accordance with a second communication protocol. The second communication protocol requires at least a second minimum volume of communication to acquire a second required information from the second device. The second minimum volume is smaller than the first minimum volume.