Decided to join the Altoids tin insert cult. Came up with these inserts you can use to transport batteries. Included are inserts for AA, AAA, 9V and 18650 batteries.
Prints easily. The overall dimensions are tight intentionally so you can pop these in without adhesive and it'll work fine.
3/19 edit: Added a version with 2xAA + 4xAAA batteries. Nice for having a backup set of batteries wherever you go.
3/29 edit: Added a 21700 version by request.
- Replaced the 9v version with one that is just open at the top (too much sample variance to make it "clever")
- Added "new" versions of the AAA holders. These are higher and make it easier to remove the batteries.
- Added an insert for Insta360 One X batteries
4/20 edit: Added a blank insert so you can create-your-own.
Doesn't matter. I used 0.28