A power supply device for vehicles, output units (10a, 10b) thereof are connected to a motor (5), includes a fuel cell (1) which is connected to the output units (10a, 10b), a capacitor (2) which is connected in parallel to the fuel cell (1), a lithium ion battery (21) which is connected in parallel to the capacitor (2) through a DC/DC converter (20), and a current control means (32) which limits an output current of the lithium ion battery (21) to at most an output upper-limit current (Ibout_lmt) when power is supplied to the motor (5) from the lithium ion battery (21) during a power running operation of the motor (5), and limits an input current into the lithium ion battery (21) to at most an input upper-limit current smaller than the output upper-limit current (Ibin_lmt) through the DC/DC converter (20) when regenerative power of the motor (5) is recovered into the lithium ion battery (21) during a regenerative operation of the motor (5).