I did test 4, 5 and 6 again with a 7 x 4 inch folding prop. With this prop I got less thrust, but a higher RPM. This means that the accelartion of the aircraft will be slower due to less thrust. But eventualy the max airspeed will be the same due to the higher rpm. The 7x4 folding prop also draws less amps compared to the 8x4.5 folding prop. So if I would just make some training flights, nothing special. Then acceleration is no must and I could choose this 7x4 prop and extend my flight time.
I hope I can test my modified setup as soon as possible and upload a video. First in air test flight will be the modified setup with the 8x4.5 prop and the 2cell Lipo. Second thest will be the modified setup with 8x4.5prop and two Nimh batteries