Magnetic Battery Charging Coupler Extender

I wanted a way to charge or check a cell from a cell pack or charge a larger cell that would not fit into a AA/AAA charger. I also needed a way to electrically connect the positive and negative flat ends. By using neodymium magnets, that made it quick and easy.

Parts needed are two sections of wire, 3mm screws (button head and flat head preferred), Two magnets each size (3 x 3mm, 6 x 3mm).

Printing: When printing the battery, I just changed filament at a random level. I did not purge the previous color. That gave it the gradual change. I chucked it in a hand drill and sanded the layer lines. This is what I did, make it your own style. I used general print settings except for the screw. Use 100% infill, 0.1 layer for strength.

Assembly: Positive terminal, wrap wire around button head and screw in top with wire aligning in slot. Bottom wire the way same with flat head screw. This should prevent electrical contact if put in charger with poles reversed as such with a regular battery. The 6mm diameter battery should press into the screw hole in the block clearing the side holes for the wire. The 3mm magnet should snap into the small hole making contact with the other magnet and slightly protruding from the block. When doing the other block set magnets so the positive and negative block ends repel to prevent accidental electrical shorting when battery is in the charger. Insert wire ends through side holes and use screw to tighten wire against magnet. 

I did not glue the small magnet in for fear the glue would isolate the two magnets electrically. The small magnet has a tendency to come out attached to the battery. I am just sliding the connector off the end of the battery to keep it in.