This is another AAA battery conversion for a LR44G button cell 6 inch caliper. Design goals were to maintain the full usable length of the caliper, maintain full use of the locking screw, maintain full use of thumb wheel, minimize additions to footprint, minimize modification to caliper, and minimize impact on the "feel" of usage. I think this works well.
Print the AAA housing with supports in the default orientation, higher layer heights will be easier to clean. Everything else can be printed without supports. The 45 degree rotation will make the corners better.
Use the button cell adapter to bring plus and minus wires out.
Put the button cell cover on over the wires to hold the button cell adapter in place.
Remove locking screw, then slide on the AAA battery housing. Feed the wires through the holes. Now put the locking screw back in before you lose it.
Plus goes to plus, minus goes to minus, you got this.
I used tin foil to make the battery contacts.
Pictures for reference.
Update 9/30/2018: Increased thickness of battery lid clips by .1 mm for a snugger fit.