AAA to AA battery adaptor

thingiverse

This thing is a sleeve for AAA batteries so they can be used in devices requiring AA batteries. You also need a small amount of Aluminium foil or similar to scrunch up and shove in the bottom to form the contact. I have portable phones that are always on charge around the house, and my kids always use the AA batteries without ever recharging them, so this way I can simply put flat AAA's into a phone and use the charged ones in my AA devices. Instructions I print out six at a time using multiply in RepG. Some AAA batteries are fatter than others, so I've been reasonably generous with the size of the inner tube. You might like to make the walls thicker on yours - I've included the SketchUp file. I've created a narrower tube at the bottom to form a shelf for the battery to sit on at the right height, and where the Al foil should be inserted. I just scrunch up a piece about the size of 50 cent piece (Australian - about two thumb nails worth) into a rough cylinder and shove in the narrower hole at the bottom. Voila!