I have something called "the Brick" it is about as thick as a brick and is 10,500 mah! I was going to use another phone I had as a spare, but the controller clamps on that baby tight, if it is rubbery, it will grip well! Extend the clamps all the way!

Pretty good pics on the Amazon store page:

http://www.amazon.com/Warranty-Zerolemon-10000mah-Extended-Protection/dp/B00Q7C6FTA