Not sure either, but hear goes. Most modern radio systems can handle 6v now. Weather you need it, is another thing. I generally don't run it unless i'm looking for more speed, and or, power. Aerobatic planes will react better from the speed, and the giant scale birds I fly, like the added holding power. I run LiPos in some planes and regulate it down to 6v. With most 120 size and smaller, everyday planes, 4.8 is all I feel they need. Lotts of schools of thought hear. That's just my 2 cents.