Getting ready to order my car and I have all kinds of questions. I live at the top of a hill. If the first thing I do everyday is coast downhill a mile and a half, can I charge to less than 100% so I can recapture all that potential energy? Seems like a waste to charge fully during the night and then go downhill. Will the car let me tell it when to stop after it gets to 90% or do I have to experiment with trial and error and figure out the optimal duration of time to charge so that I start out the day with less than a full charge but have regenerated enough to have a full charge at the bottom of the hill?