In my leo, I cut away some of the plastic that supports the normal stick pack to make room for the wires, thus in doing so, the underside of the turret doe snot bulge out at all. I think its the top turret halve that is pushing against teh wires when you try to close it that pushes the bottom back of the turret out.

Anyway i have been using Lipos (2S 7.4V) in all my tanks ever since I started playing tanks becoz I had some spare packs lying ard that I used to use them for my planes. I have been tanking for 4 years and now, almost all my club members use lipos due to teh size of the packs and the 'charge today and play next month' properties of lipos.