Objectives : have a 4G capable drone and a long flight time
Constraints : conserve CG position and flight characterics.
The battery is composed of 9x 21700 cells mounted in 3s3p (11.1V ans 15000mAh).
Each battery cell is a d21mm*h70mm cylinder of 63g.
The 4G dongle is a huawei (see uavpal softmod).
The CG of the original [canopy + battery] is located, of course, next to the CG of the original battery. Inertia axis are influenced by the canopy. Thus one axis has a "pitch" angle that need to be imitate. The cells positions had been chosen so as to conserve CG position and conserve the orientation of inertia axis. The battery cells had also been placed so as to have the best compromise without modifying the others parts of the drone.
Here you can find a video of the project. NB : I will not share design for obvious reasons. PS : scotch = tape