On all my profiles of all sizes, and at least 2 full fuse models, I have been making a special effort to install the pack on the inboard side in order to use centrifugal force to seat the battery and a strap just to keep it from falling out. Unfortunately that is not always feasible. I am currently modfying a Shark 402 with a battery pocket in the wing - like the Electric Super Clown. I also made it so it can slide a total of about 3 inches fore/aft for balance.
The small electric motors are actually quite a bit lighter than reedies, so it is hard to balance them without getting the battery forward som but be careful. I like the idea of keeping the battery back and lengthening the nose to get the motor out front to get the balance.