So I decided to make my first 5v box mod. I wanted a long run time so I ordered a pair of 18650s. When they arrived I realized my mistake. These things are HUGE! I decided to just deal with it and went to Radio Shack in search of a suitable box to put it in. Long story short is.. I made the box mod and it works well, but it's way too big. I would like to know what the largest capacity battery is that will still fit in a AA size enclosure.