There are 'A' cell batteries that can have as much as 2700mAh capacity. 'A' cells are slightly larger diameter than 'AA' cells and just barely longer. [link=http://www.hangtimes.com/rxpacks.html]NOBS[/link] sells rx packs made with these batteries. These are NiMH batteries. Be sure to use a good charger to get the most out of them.

-Mark