This guy actually makes real electric superchagers, but their power draw is similar to that of three starter motors. It takes thousands of watts to pump several hundred CFM of air at more than several PSI. The weight of the batteries and motors makes it a bit impractical compared to a turbo or regular supercharger.

http://www.boosthead.com/home.php

http://www.turbomagazine.com/tech/0406tur_knight/