4x AA battery holder / case

thingiverse

You can buy this thing for 76 euro cents at ALiExpress, but hey, we're makers, so I designed a classic one that fits perfectly into my OTTO robot. For the + contacts, I used 4 pushpins that I pushed through the holes with a hot solder iron. For the - contacts, I had some springs lying around and Hot Glued them into the little rings to center them. You can probably figure out the rest yourself? Have fun!