Twin ignition and twin electrical start system for a vehicle

An electrical circuit arrangement for a vehicle which permits the starting voltage and/or the ignition voltage for the vehicle engine to be derived from the vehicle battery or from an attached camper battery, and which permits simultaneous charging of both batteries comprising in combination:

• a vehicle battery having one terminal connected to ground;
• a vehicle starter relay;
• a starter motor having one terminal connected to ground and its other terminal connected via the controlled current path of said vehicle starter relay to the other terminal of said vehicle battery;
• a vehicle alternator having is output connected to said other terminal of said vehicle battery;
• a conventional vehicle ignition switch having a battery voltage input terminal and at least an ignition voltage output terminal which is connected to the ignition coil, and a starter control voltage output terminal;
• a first switch connecting said starter control voltage output terminal of said ignition switch to the control terminal of said vehicle starter relay;
• a camper battery having one terminal connected to ground;
• first circuit means, including the controlled current path of a further starter relay, for connecting the other terminal of said camper battery to said other terminal of said starter motor;
• a second switch connecting said starter control voltage terminal of said ignition switch to the control terminal of said further starter relay;
• a single pole double throw switch means, having its movable contact connected to said battery voltage input terminal of said ignition switch, for selectively connecting said battery voltage input terminal to said other terminal of said vehicle battery or said other terminal of said camper battery, whereby the position of said switch means determines which of the batteries supplies the voltage for the vehicle motor ignition coil and for control of said starter relays and the closure of one or both of said first and second switches determines which one or both of the batteries supplies the starter voltage;
• and, second circuit means for connecting said output of said alternator to said other terminal of said camper battery only when an output voltage is present at said ignition voltage output terminal of said ignition switch and no output voltage is present at said starter control voltage output terminal of said ignition switch.