Control method of information terminal

A battery pack leasing system for managing battery pack leasing reservations, the battery pack leasing system comprising:

• a battery leasing device configured to:
• store and manage a plurality of battery packs;
• electrically charge one or more of the stored plurality of battery packs;
• acquire charge information relating to a remaining charge of each of the plurality of battery packs stored in the battery leasing device;
• acquire deterioration level information indicating a deterioration level of each of the plurality of battery packs stored in the battery leasing device, the deterioration level being different from the remaining charge of a battery pack;
• and
• determine battery class information for each of the plurality of battery packs based on the deterioration level information;
• a server device configured to store information related to the battery leasing device,
• wherein the battery pack leasing system allows a user to reserve a target battery pack stored at the battery leasing device, by an information terminal which is connected to the server device via a network,
• wherein the information terminal specifies battery class information of a battery pack associated with the user,
• wherein the battery leasing device transmits the battery class information including the deterioration level information indicating the deterioration level of each of the plurality of battery packs stored in the battery leasing device, to the server device,
• wherein the server device receives, from each of a plurality of battery leasing devices, battery class information including the deterioration level information indicating deterioration levels of the plurality of battery packs,
• wherein the server device stores battery management information including the battery class information that includes the deterioration levels of the plurality of battery packs,
• wherein the battery pack leasing system is configured to perform:
• identifying, among the plurality of battery packs, a candidate battery pack available for leasing to the information terminal when battery class information of the candidate battery pack matches with the battery class information of the battery pack associated with the user,
• displaying, on a display screen of the information terminal and only for the candidate battery pack matching the battery class information of the battery pack associated with the user, a deterioration level of the candidate battery pack available for leasing,
• transmitting candidate information that identifies the candidate battery pack available for leasing with corresponding deterioration level information to the information terminal of the user, the candidate information further including information which identifies a candidate battery leasing device that has the candidate battery pack, and
• displaying, on the display device of the information terminal of the user, information of the candidate battery leasing device, and
• receiving, via the network and from the information terminal, a reservation request for the target battery pack stored in the candidate battery leasing device, and the target battery pack being the candidate battery pack and having battery class information matching the battery class information of the battery pack associated with the user,
• wherein the information terminal of the user transmits the reservation request, requesting reservation for the candidate battery pack, to the server device.