ORIGINAL: jrcaster
Being pushed in is not going to be your problem. Since your hatch is on the bottom, any time you make a turn, or do a loop, the weight of the battery pack is going to be pushing out on the hatch. I don't see any stiffeners running lengthwise on the hatch.
I don't believe that will be the case as the battery pack will be velcroed onto the battery tray and removable scrap wood will be going across the battery pack widthwise.
Also on picture 1 you have a hole for 1 hatch, but on picture 3 you have two hatches.
In photo 3 only the forward section of the fuselage is the hatch. Behind the hatch is two holes drilled into the fuselage to vent the ESC.
Instead of running the ESC in the fuselage, why not have it in the cowl with the motor? That will solve two problems at once. It will be easier to keep cool, and the weight will help balance the plane.
Can not do, there is a harness switch connected to the ESC with a very short wire. I did not want to cut out a 2nd hole for a switch (this plane was originally a glow plane so it already had a switch cutout) I wanted to use the switch cutout that was already there.
The conversion is completed, I will be posting photos later of the completed project. Just waiting to order the proper battery pack now.