Motor vehicle starting system

In a motor vehicle haivng a first wet-cell battery, a motor-operated recharging generator, a motor starter, a starter relay, an ignition system, and a key-operated switch having a starting position for operating the starter relay and the ignition system, and a running position for operating the ignition system exclusive of the starter relay, and first circuit means connecting said starter relay, ignition system and key-operated switch to said first battery, a cold weather starting system including a second wet-cell battery, second circuit means connecting said first and second batteries in parallel to said generator, and third circuit means for connecting said first and second batteries to said motor starter through said starter relay, either in series for cold weather starting or in parallel for warm weather starting, said third circuit means including a switching relay which, in normal non-energized position, connects the first and second batteries in parallel, and which in an energized position, connects said first and second batteries in series, and a switch to energize said switching really, series connected between the solenoid of said switching relay and said ignition system and being an automatic switch responsive to the ambient temperature and taking an open and a closed position above and below a predetermined ambient temperature.