I glued 3/4" triangular balsa to increase the gluing area flush to the outside of the LG bulkheads and added a 1/4" X 1/2" AC plywood plate to the fuselage sides 2-3 inches behind the rear most LG bulkhead. Then I glued the CF/wood battery platform (in the kit) to the LG bulkheads & triangular stock and ply plate. I use 2 X 1" velcro straps around the tray to hold the batteries. So far nothing has come loose.
Dave