I am currently trying to cheaply build a robot that will have to power the following:
2x 12 v Window motors (the kind that lifts your car window) http://www.robotmarketplace.com/products/AME-210-1009.html
2x windshield wiper motors http://newsgroups.derkeiler.com/Archive/Comp/comp.robotics.misc/2007-07/msg00091.html
4x 5v servos http://www.hobbypartz.com/12exiseb1.html
5v ip camera http://foscam.us/products/foscam-fi8910w-wireless-ip-camera.html
plus an arduino uno ethernet with 2 motor controllers
All in a small package with at least 10 minutes of battery life, hopefully more
Thing is, i have no idea how to power all these things. What kind of battery/power supply do i need? Oh, also, I intend to have it be able to drive into a docking station to charge itself.