I might be misinterpreting your question, but are you asking why there isn't an alternator included which can run off the lithium battery? Sorta like a perpetual motion type deal where the battery could turn another shaft other than the axles which would have an alternator attached to it and constantly continue charging battery by using same battery's power.
I am not an electrical engineer by any means but have fixed enough vehicles in my time to think that the power it takes to turn this type of ac alternator may cancel out any benefit in charge to the same battery. I may be wrong in this assumption but would figure this is the reason you don't see this type of setup on any electric vehicles as of now. Perhaps this may change with future innovations.
Good thought though.
-Ken
