Its for the sundowner 50. It already a bit nose heavy as the 91 surpass is a little to big for the plane. Only way to not add dead weight is get that battery behind the wings. There is no room for adjustment anywhere else. Thanks guys. And to secure the battery I was going to cut a couple "dents" or slots in the ply wrap the battery in faom and throw velcro all around it. When Im done with it Ill mount everything but the battery and see how much weight I can play with.

I was just afraid of those stringers. They feel very soft and I wouldnt want any high g maneuvers to break them out with the weight of the tray and battery on them.