What is the most powerful rocket man has ever built?
it depends, many argue the Rocketdyne F-1 is the most powerful single cell rocket in history. But it depends on what the limitations are. These are the rockets designed by NASA for use on the space shuttle booster's. http://www.primeportal.net/space/miles_lumbard/rocketdyne_f1/
The batmobile ?
The most powerful rocket that has ever been built was the N1 rocket. It was used for space race, moon mission as it has five stages. The first flight that it made was on 21st February 1969.