Lets talk battery adapter tubes...

[mattlward]

@Lightbringer

Most cases, as long as the length is compatible, you can just drop in a smaller-diameter cell as-is, no rings or spacers or anything, and the internal springs will hold it in place without rattling around. I’ve even used an 18650 in a 26650 light without issue.

Still, anyone who’s anal-retentive enough to “need” the “proper” spacers can do it as above, a sheet of paper folded over and wrapped around the cell would be enough, else a thick rubber-band (like those fat ones that go around broccoli stalks) would keep the cell centered and cushioned nicely.

I try to find things like o-rings and such. It is not anal retention… I had a flat top 18650 in one of my favorite 26650 lights, fit tight and seemed to work well but it shifted and scuffed up the wrapper and dead shorted on the positive end… Talk about exciting!

I have several proper 18650 to 26650 tubes now, but the one I need the most is 18mm to AA for something I am working on.

Where it does get anal… I hate anything that rattles. Flashlight, shotguns, cars… should not rattle!