My invention : The alternative power source for an automobile

I am proposing a simple working model for an alternative battery source for automobiles (preferably four wheelers).
It works on the basic faraday's law of induction and might be a valid substitute for a car battery or a car alternator at moderately high contant speeds.
It might need the car battery to run the car to a certain point where the induced emf from this device is large enough to drive the components of the car. After that an automated control, that is contantly getting feeds from the accelerometer, gear box and the alternative battery, will pass on the control to this alternative source. This automated control will also take care while the car is being driven in "reverse" gear.
I do not know how economical this system is, coz the control might be a little pricey but not that much. If its all digital all we need is a bunch of C code lines to start the automation.
Though the battery costs 40$ each and is good till 3-4 years. It might extend the battery life to maybe 10 years. I still have to do the math based on the statistics.