For custom sizes and container options, try the Online Generator

This is an OpenSCAD script for coin cell storage based on Gridfinity Rebuilt. The advantage over existing gridfinity-compatible coin cell storage models is that this model can use the full Gridfinity Rebuilt feature set, including the press-fit magnets.

The model is fully parametric to allow for custom coin cell sizes and box dimensions. The script will automatically fit as many coin cells as possible in the available space.

GitHub is more up-to-date.