Feasibility of using secondary props to generate power on an electric model aircraft Beginning with the aeroplane itself, it is a small, fixed wing model aeroplane, reminiscent design-wise to a Cessna 172. It is completely battery powered and has a primary prop attached to a motor housed in the nose of the aeroplane.

I was wondering how feasible it would be to attach two props behind the wings of the aircraft, one on each wing, connected to a generator which would then connect to the main battery, so as to recharge the battery while the aircraft is airborne. 

I haven't been able to find much information regarding this, so any ideas would be greatly appreciated.
It seems to me to be somewhat pointless - your extra 2 props will create more drag, thus the main drive motor will need to work harder for the same result as without them. They're effectively cancelling each other out, and the laws of thermodynamics tell us that energy will be lost from the overall system.

It's much like connecting a solar panel to a lightbulb; physics just doesn't allow for a 100% efficient system, so it can't work.