voltage battery 170 is greater than a predetermined value which is able to start the engine in a s 610 if it is determined that the state of charge of the high voltage battery 170 is greater than the predetermined value in the s 610 the engine 100 is started via the first motor 120 in a s 680 if it is determined that the state of charge of the high voltage battery 170 is less than the predetermined value in the s 610 the control portion 200 generates an emergency signal to notify the driver of an emergency charging mode then the two way converter 180 dc dc converter boosts the voltage of the low voltage battery 190 to charge the high voltage battery accordingly once the state of charge of the high voltage battery 170 exceeds the predetermined value in a s 630 the second motor 140 is operated to start the engine 100 once it is determined that the engine 100 is operational the voltage boosting of the two way converter 180 is stopped in a s 640 and the engine 100 charges the high voltage battery 170 through the second motor 140 the state of charge of the high voltage battery 170 is then monitored by the controller until it is determined that the state of charge of the high voltage battery is greater than a predetermined value in a s 650 here the predetermined value can be varied depending on the design specification the control portion 200 then generates an emergency release signal to notify the driver of an emergency charging mode release.