Gumstick Battery Eneloop Charging Adapter

thingiverse

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. In addition to the printed adapter, you'll need: --Two #4-1/2" pan-head screws --Two #4-1'2" flat-head (countersink) screws --A length of 22 AWG (or smaller) wire 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. 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. I designed this model from scratch, but some inspiration came from this similar adapter (great minds think alike, and all that): https://www.thingiverse.com/thing:3047798