Untested design, please report any issues!

A holder for a single button cell. It can be adjusted to almost any battery, or multiple cells if you add the height of the cells.

Usage: Print and stick two pieces of wire through the holes in the sides. Slide in the button cell. If the fit is too tight, modify the parameters, starting with tolerance. Likewise if the fit is too loose, set tolerance to a smaller value.

Example files:

CR1225 cell holder:
diameter=12mm
height=2.5mm
tolerance=0.5mm
wall thickness=2mm

CR2032 cell holder:
diameter=20mm
height=3.2mm
tolerance=0.5mm
wall thickness=2mm