While the "20 volts" part might not be correct, I've been a fan of using these small Dewalt drills for personal and robotics projects.
http://www.homedepot.com/p/DEWALT-20...71C2/204279858
While its not used as much, a right angle drill can be really useful especially during those "crisis" moments of a last second fix or redesign late in the year when most of the robot is assembled to get into some tight spots.
http://www.homedepot.com/p/DEWALT-20...740B/203316372