battery 124 is also configured to recharge the lv battery 128 the dc dc converter 126 converts the output of the hv battery 124 into an input to charge the lv battery 128 typically the lv battery 128 provides electrical power for low voltage vehicle sub systems 129 such as lights radio and the like the control system 116 is now described in further detail the control system 116 includes a control unit 130 that is configured to control the throttle 122 the spark timing and the electric machine 112 in some embodiments the control system 116 is connected to the mechanical accessories 114 such as in cases in which it is needed to activate an ac compressor clutch or some other actuator it will be appreciated that the control unit 130 may in practice communicate with various other automotive systems and that the system shown in fig1 is simplified for clarity furthermore while the systems shown in the drawings are incorporated into an automotive vehicle the system is not so limited and may be incorporated into an aircraft a marine vessel or any other application in which an internal combustion engine may be used the control unit 130 includes a processor 140 a computer readable medium e g.