module cr18650() {
  d = 18+1;
  l = 65+3.5;
  nl = 1.1;
  nd = 6;
  rotate(90, [0, 1, 0]) {
    cylinder(l, d/2, d/2);
    translate([0, 0, l])
      cylinder(nl, nd/2, nd/2);
  }
}