The law of conservation of energy precludes the possibility of a perpetual motion machine. In a nutshell, the vehicle requires a certain amount of energy to keep it moving. If you wired up a system that charged the battery when you were moving through a set of alternators attached to the wheels, the alternators would exert a drag on the vehicle which you would need to overcome by drawing the same or more power from the battery in order to keep the car moving.With any new technology it takes time to perfect it.
I wouldn't be surprised if they came up with a system that charges the battery while you drive as the wheels are turning.
What you're thinking of can work. But only when braking. The so called regenerative braking what uses the drag from the alternators to slow you down.