Gumstick Battery Eneloop Charging Adapter

prusaprinters

<p>An adapter for charging NiMH gumstick batteries in an Eneloop AA/AAA charger. I didn't want to buy a charger just for my Walkman gumstick batteries, so I came up with this adapter instead -- NiMH AA/AAA batteries have the same voltage as a gumstick, so the Eneloop charger doesn't know the difference. This adapter would likely work with other AA NiMH chargers as well.</p> <h3>Print instructions</h3><p>In addition to the printed adapter, you'll need:<br/> --Two #4-1/2" pan-head screws<br/> --Two #4-1'2" flat-head (countersink) screws<br/> --A length of 22 AWG (or smaller) wire</p> <p>There are channels inside the adapter to route the wires for a clean appearance. The screws act as the battery terminals -- inside the gumstick compartment, use a pan-head at the top (positive) and flat-head at the bottom (negative). On the AA side that interfaces with the charger, use the opposite -- a flat-head on the top (positive) and pan-head on the bottom (negative). No soldering needed, as long as the wire is making contact with the screws then you'll get a good connection. You can tighten or loosen the screws to adjust the fit.</p> <p>To minimize overhangs, the adapter is best printed upright. Take care to get good bed adhesion as there isn't much surface area in this orientation. A potential future revision might allow for printing the adapter on its side.</p> <p>I designed this model from scratch, but some inspiration came from this similar adapter (great minds think alike, and all that): <a href="https://www.thingiverse.com/thing:3047798">https://www.thingiverse.com/thing:3047798</a></p>