18650 Battery holder with reverse voltage protection

thingiverse

Yet another 18650 battery holder. I figure I could find one that's good enough, but the ones by enif are really popular and I worry about the plastic as a spring if it gets hot. I only use stranded wire so wrapping it as a connector would be a real pain unless I tinned it, I guess. But the main reason I dove in is because I couldn't find any that provided reverse voltage protection. I give my projects to all kinds of people and it's just a matter of time before they put in the battery backwards. This provides protection for the now popular 18650 batteries with buttons on the positive end. It uses a faucet spring and .01 inch, .3 mm brass as the contact surface providing reliable contact. I use some of these in environments that vibrate a lot so I made a clip that will keep the battery securely in place. I use an 8mm and a 10mm strip, cut to length and bend as shown in the pictures. The 10mm wide strip is for the positive non-moving end. Make sharp bends and make sure it seats below the raised portion that provides reverse voltage protection. I always put a battery in backwards and measure to see if I have no voltage. You can glue them side by side or back to back but you'd lose the clip retainer. I just use my soldering iron to burn a hole for the wire to come out and CA it in place. Have fun and thanks for looking. Cheers, Kisssys