A more generic version of my "V393 to V303 Button Cell Adapter" http://www.thingiverse.com/thing:8410

The file is set up to create a simple crescent shaped V393 to V303 Button Cell Adapter but you can insert sizes for whatever button cells you have on hand into the user_variables section.

Please note if the smaller battery is not as tall as the larger battery this holder will not work for top & bottom type contact holders as a thin layer of plastic will be in the way!

Also... you can't use this script to adapt a large battery to fit into the space intended for a small one!

0. Insert height & diameter values into .scad file for your batteries
1. Generate .stl file
2. Ensure item is correctly oriented and placed on build platform
3. Print Raftless
4. Clean off nasty plastic, check fit and adjust if necessary
5. Insert small battery into recess (tape/glue may be requried to keep it in place)
6. Insert into gadget with gap between crescent points facing the side contact
7. Reduce battery waste, save the planet