I don't have a problem with the battery compartment size. You don't need a battery that fills the whole space perfectly, and there are tons of SMALLER batteries that should fit just fine. I've got a few 2200, 1000, and 600mah 3s's that should give an acceptable amount of runtime for the day's needs. I think the most expensive of those was only $16 from Value Hobby. The 2200 gives me about an hour (more if it's just trail cruisin') in my 8lb+ Wraith, so should do much better in a ~5lb Capra, and keeping a backup in my back pocket would be no big deal if more runtime was needed (I rarely burn through more than a 2200 on a single outing due to my limited mobility.) The smaller packs will be reserved for backyard driving and/or competition use where less weight up high would be appreciated more. In my opinion, the con of having to swap out multiple smaller packs is more than offset by the pros of less weight and a lower center of gravity.
