The car has a average voltage of 14.4vdc, and will not start below 13vdc.
IS THIS A GOOD CHOICE FOR A POWER SUPPLY?
Average voltage is 14.4v is it?
Car refuses to start under 13v
And who took these measurements? Average voltage from the alternator is around 14v the car would have issues if the battery read 11.5v (starting it) but 12.5v to 13v is plenty to turn the starter motor...
your values seem off.