[Piwoslaw]

Originally Posted by sprkthead2

You mean a series hybrid. GM coined the phrase range extender, which is a series hybrid.

I think there is a difference between those two. A series hybrid is an electric car with a generator engine large enough keep a charge for as long as it has fuel, no matter how you drive. A range extender is an electric car with a small engine which adds some juice to the batteries (or actually slows down their rate of discharge), but not enough to allow any type of drive for an indefinite time. At a slow speed the small genny may barely charge the batts, but the generator will supply only, say, 80% of the power needed to sustain highway speed. The car will have to slow down when the batteries discharge, though this will happen after a distance 5 times greater than without the engine.

I think the undersized genny is better, since it will work great in a typical driving scenerio: drive some, stop, drive some more. The batteries recharge during the stop. Even on the highway you could go 12-15h, with stops every 3-5h for lunch+pee, then sleep while the genny recharges. But a series hybrid isn't the most efficient set-up for highway driving.