Battery box for 3 AG13/LR44 cells

Instead of real DROs I use calipers on my lathe and milling machine . These operate with AG13/LR44 batteries and as I only hacked Chinese models the current consumption even in standby isn't the lowest. For this reason I quite often end up with empty batteries when I want to do some work. So far I took the batteries out and taped them somewhere to the machines but that quite often left some glue residue which prevented good contact.

Simple solution: a tiny battery box. The hole on the bottom is for an optional Ø10x2mm magnet which can be glued in with Epoxy.