Sig does a pretty good job with the balancing. This is my third sig plane (two kits and one arf), the first two are still flying, the third being this hog. Both of the flyable ones balanced without any lead, putting the batteries in the recommended places. I checked the balance on my hog to see where i should put the servo tray in, and the thing balanced PERFECTLY on the CG. Great planes has a knack for this too. I have two planes made by Great Planes (one kit and one arf) that needed zero lead, putting the batteries right on the CG.