Battery Box 18650

Here is my battery box for two 18650.
Print two lids and one body.
Assemble using M3 screws and M3 nuts. Insert M3 nuts according to image.

Make metal contacts using i.e. scrap can of tuna and cut it 5mm wide, solder wires as you need.
Lid_v2 can be used if you prefer springs instead of the above scrap tuna can, in this case use the longer body.

If you have a well tuned 3D printer you do not need support (maybe just at the bottom, see image).

If you cannot find M3 button-screws and nuts....
https://www.aliexpress.com/item/1005002275589280.html
https://www.aliexpress.com/item/1005002856385340.html