Nissan Altima Electric Supercharger Photo
this is the only example of an electric supercharger i have ever seen that works. but it's fiercly debated, primitivly tuned, you need a massive battery pack, and in the end it's just a little eaton driven by 3 rewound starter motors with a primitive on off controller and it's similar to using a very small shot of nitrous yet it adds like 300lbs of weight to the car. It shows the concept works somewhat but electric motor and battery technology just isnt there to put out the kind of power you need. for the people considering buying the little mini electric superchargers just remember that no way in hell is a 30-50hp electric motor going to be smaller than a large shoebox, and require you to put at least 4 more batteries in your car. i used to mess around with dc electric race cars in highschool and believe me the amount of power you need to drive a supercharger would be very hard to generate from current electric motor technology may in 10 years.