Case for AA, AAA, cylindrical batteries

3D-printable storage boxes for small sets of cylindrical batteries.

Designed to be leak-resistant: the body and lid have full-length overlap and there are no unnecessary openings. They are also a very snug fit so they should be secure without any additional fasteners.

Modify the second argument to `battery_case()` to set the number of cells the case should contain. The largest sizes that I have tested out are 6 × 1 cells and 4 × 2 cells.