But if you’re waiting more than ten minutes at a charging station for a place in line, even a small generator will shorten one’s re-charging time.
Sure, it might shorten it 10 or 12 seconds, as long as you have it on for 10 or 12 minutes. Meanwhile you’re carrying along an extra 200 lbs. of motor generator for all the miles you drive. just compare the power from a 10 hp generator to a 200 hp car. The car uses much of the power going 70 mph for 10 hours. The generator would have to run 10x200/10 = 200 hours to produce the same horsepower-hours of energy.