What’s the worst thing that can happen when you are trying to show off a project? Dead batteries might not be the absolute worst thing, but it is pretty close to the top of the list. [KermMartian] has this problem every year at World Maker Faire with demos based around calculators. At first, he tried wedging power supply wires into the calculator using dead batteries to hold the wires in place. However, it didn’t take much wear and tear before the wires would pull out.
The solution? A 3D printed battery form that accepts metal hardware that can connect to the external power supply. The AAA-sized plastic batteries insert into the calculator’s battery compartment and the small machine screws and washers form the connection points.
Then again, you don’t have to get this fancy. We’ve seen people do the same with a piece of wood several times (although we don’t recommend putting 5V into a 3V device). Still, the 3D printed forms might have some other interesting uses like embedding instrumentation or other goodies inside.
If you want to print working batteries, you’ll need to wait for some different printer technology (unless you count filling a plastic form with metal electrodes and electrolyte). However, the video below shows some Harvard research about printing tiny batteries with special printing techniques.