Patent attributes
A utilization index IDX is calculated based on one or more parameters (the number of times of charging/the number of trips, total battery charger connection time/total vehicle stop time, total EV traveling distance/total HV traveling distance, total EV traveling time/total HV traveling time, total EV traveling distance/total traveling distance, total EV traveling time/total traveling time, total charge amount/total fuel supply quantity) obtained based on a ratio of an EV traveling utilization level to an HV traveling utilization level or a total traveling utilization level, and the utilization index IDX is stored. Since the utilization index IDX is calculated such that as each parameter is larger, utilization of charging of a battery by a battery charger is performed more sufficiently. Accordingly, the utilization index IDX can be used as an index that offers more accurate determination regarding a utilization status of the battery charging.