My Stik 30 underwent significant surgery this week and lost nearly 10 ounces as a result. The wing area is around 450 squares, so that's a significant amount. Part of that weight was SIX ounces of lead in the tail. I put in a larger battery and moved it as far aft as it would fit.

I made this hatch yesterday. Under the battery is a piece of foam that comes with Hitec receivers. The rails are not full-length because as the fuselage becomes narrower, the battery would not fit between the rails.