I've heard this a lot from people who use a Minkee backing and no batting. The solution is to use batting. You could also try a layer of cotton between the Minkee and the top, but I can't say if that's worked for other people.
I'm not sure what kind of batting you tested with, maybe try a thicker cotton or poly. It will be a warm quilt for sure.
Why does your son not want any batting?