40volt black and Decker printable mount

My first build, I used laptop batteries. I could go about 10 miles at 17 mold an hour. Next I had my son-in-law print mounts for black and Decker 40 volt batteries. I get speed wabble at about 17 miles an hour. But I can go around 10 miles and two 3Amh batteries. I carry a second set and finish my ride. Works great.!