Power supply system for electric powered vehicle and control method thereof

摘要

A power supply system for a hybrid vehicle includes a main power storage device and a plurality of sub power storage devices used selectively. When an SOC of one of the plurality of sub power storage devices decreases to a predetermined value or smaller, an ECU selects this sub power storage device as a sub power storage device to be charged. The ECU controls a connecting unit such that the sub power storage device to be charged is connected to a second converter. Furthermore, the ECU selects the HV mode as the travel mode. In the HV mode, electrical energy stored in an electric powered vehicle is maintained because of electric power generation by an engine.