A power supply system for an electric powered vehicle capable of generating a driving force of said electric powered vehicle from electric power supplied on an electric power line (MPL, MPN), comprising: a plurality of chargeable and dischargeable power storage devices ( 6-1, 6-2, 6-3,...); a plurality of converters ( 8-1, 8-2, 8-3,...) connected between said electric power line (MPL, MPN) and said plurality of power storage devices ( 6-1, 6-2, 6-3,...), respectively, and each configured to include a plurality of power semiconductor switching elements (Q1A, Q1B/Q2A, Q2B) for converting electric power between an associated power storage device of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) and said electric power line (MPL, MPN) bidirectionally; and a control device for controlling turning on and off each said power semiconductor switching element of each said converter, wherein: said plurality of power semiconductor switching elements (Q1A, Q1B/Q2A, Q2B) include a first switching element (Q1B/Q2B) electrically connected between said electric power line (MPL, MPN) and said associated power storage device, characterized in that said control device, in a predetermined mode allowing said plurality of power storage devices ( 6-1, 6-2, 6-3,...) to be charged with electric power supplied on said electric power line (MPL, MPN),: is configured to select at least a part of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) as that to be charged and also to hold on said first switching element (Q1B/Q2B) unconditionally in said converter associated with the power storage device selected as said that to be charged to avoid turning on/off said switching element, and on the other hand to hold off said first switching element (Q1B/Q2B) in said converter associated with a remaining power storage device of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) other than said that to be charged, to charge said plurality of power storage devices ( 6-1, 6-2, 6-3,...), wherein in said predetermined mode said electric power line (MPL, MPN) is configured to receive charging electric power originating in electric power supplied from a power supply (90, 90#) external to said electric powered vehicle. a plurality of chargeable and dischargeable power storage devices ( 6-1, 6-2, 6-3,...); a plurality of converters ( 8-1, 8-2, 8-3,...) connected between said electric power line (MPL, MPN) and said plurality of power storage devices ( 6-1, 6-2, 6-3,...), respectively, and each configured to include a plurality of power semiconductor switching elements (Q1A, Q1B/Q2A, Q2B) for converting electric power between an associated power storage device of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) and said electric power line (MPL, MPN) bidirectionally; and a control device for controlling turning on and off each said power semiconductor switching element of each said converter, wherein: said plurality of power semiconductor switching elements (Q1A, Q1B/Q2A, Q2B) include a first switching element (Q1B/Q2B) electrically connected between said electric power line (MPL, MPN) and said associated power storage device, characterized in that said control device, in a predetermined mode allowing said plurality of power storage devices ( 6-1, 6-2, 6-3,...) to be charged with electric power supplied on said electric power line (MPL, MPN),: is configured to select at least a part of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) as that to be charged and also to hold on said first switching element (Q1B/Q2B) unconditionally in said converter associated with the power storage device selected as said that to be charged to avoid turning on/off said switching element, and on the other hand to hold off said first switching element (Q1B/Q2B) in said converter associated with a remaining power storage device of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) other than said that to be charged, to charge said plurality of power storage devices ( 6-1, 6-2, 6-3,...), wherein in said predetermined mode said electric power line (MPL, MPN) is configured to receive charging electric power originating in electric power supplied from a power supply (90, 90#) external to said electric powered vehicle. said plurality of power semiconductor switching elements (Q1A, Q1B/Q2A, Q2B) include a first switching element (Q1B/Q2B) electrically connected between said electric power line (MPL, MPN) and said associated power storage device, characterized in that said control device, in a predetermined mode allowing said plurality of power storage devices ( 6-1, 6-2, 6-3,...) to be charged with electric power supplied on said electric power line (MPL, MPN),: is configured to select at least a part of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) as that to be charged and also to hold on said first switching element (Q1B/Q2B) unconditionally in said converter associated with the power storage device selected as said that to be charged to avoid turning on/off said switching element, and on the other hand to hold off said first switching element (Q1B/Q2B) in said converter associated with a remaining power storage device of said plurality of power storage devices ( 6-1, 6-2, 6-3,...) other than said that to be charged, to charge said plurality of power storage devices ( 6-1, 6-2, 6-3,...), wherein in said predetermined mode said electric power line (MPL, MPN) is configured to receive charging electric power originating in electric power supplied from a power supply (90, 90#) external to said electric powered vehicle.