Hi Randy, I use 2, 5 cell packs in series, I use Thunder Power Extreme and they are 5000 mah. I can get 2, 5 min flights no problem. But everyone fly different so I would fly a 5 min flight and see what mah you put back into the packs. You wont want much more than 4000 mah going back in to stay on the safe side. I fly like I stole the plane and the motor only gets a little warm. I swing a 20/12 prop. Not sure about the weight. I have a new in box Great Planes 1/3 scale pitts I need to assemble soon. Now the 1/3 scale pitts is going to get the 5345/middle one with 12 cells,,,look out when that goes up!