ORIGINAL: luis_hac
You don't have to solder them. If I remember right there is a "battery holder", holds 4 AA batteries and looks like a square pack with a universal connector you can get.
This is very bad advice for an airplane application. Putting foam around it won't be enough to isolate it completely from vibrations. The vibrations can cause the battery cells to lose contact in the pack which can cause loss of control of the plane. Any battery that goes in a plane needs to have the connections to the cells properly soldered or spot welded.
Ken