holesep=19;
holedia=2.4;
slotwidth=4.2;
slotlen=9.5;
freespace=33.71;
freestart=22.52;

centerx=freestart+(freespace/2);
centery=20.88/2;

difference() {
   union() {
      import("battery-repaired.stl");
      cube([59.5,20.88,2]);
   }
   translate([centerx-(holesep/2),centery,-1])
      cylinder(h=4,r=holedia/2);
   translate([centerx+(holesep/2),centery,-1])
      cylinder(h=4,r=holedia/2);
   translate([centerx-(slotlen/2),centery-(slotwidth/2),-1])
      cube([slotlen,slotwidth,4]);
}