AAA to AA Battery Adapter

I ran out of AA batteries, but had a bunch aging AAA batteries laying around so I created an adapter to use AAA batteries in products requiring AA batteries.

Just print the STL, grab some aluminum foil, aluminum duct tape, or copper duct tape, and wrap it around the negative terminal extender. Slide the now conductive negative terminal extender into one of the ends of the adapter, and slip in your AAA battery, and —voilà— you've got a AA Battery.