18650 Spare Battery Holder

[grindill]

Since I couldn't find anywhere to purchase a holder for 18650 batteries, I decided to make my own. At this point I only needed to be able to store batteries, not actually connect them but I'm sure that the design could be modified with some springs and wires.

I got some 7/8" OD x 3/4" ID Acrylic Tubing and some 3/4" Clear Extruded Acrylic Rod from www.usplastic.com. I bought the wrong plastic endcaps so I stopped off at Home Depot and grabbed some 7/8" Plastic Endcaps for furniture legs. I'm glad I ordered the wrong size though because the ones from usplastics were orange and the ones from Home Depot were white. Much nicer. I already had some nice little Felt Feet stored away so I used some of those for cushioning.

I had to do all the cutting by hand since I don't have a shop or any real power tools. This required a bit of sanding afterwards but I think everything turned out quite nicely. I secured the rod ends inside the tubes with some super glue and that's about it. Nice and tidy.

The little spacer I made for the 2x tube had to have it's sides sanded down so it slides nicely. Otherwise the fit is too tight and it'd get stuck there.

Hope you like it.

Later

 

[alphazeta]

I like the idea. Seems promising for making wired external battery packs (headlamps, bike lights, etc). Very clean looking.

For some reason I always thought those keep2go tubes would hold 2 18650s.
https://www.4sevens.com/index.php?cPath=82
I know they can hold 4 cr123s but am not sure if the diameter will accommodate the 18mm diameter cells. Can anyone verify?

 

[NoFair]

I like the idea. Seems promising for making wired external battery packs (headlamps, bike lights, etc). Very clean looking.

For some reason I always thought those keep2go tubes would hold 2 18650s.
https://www.4sevens.com/index.php?cPath=82
I know they can hold 4 cr123s but am not sure if the diameter will accommodate the 18mm diameter cells. Can anyone verify?

Mine hold 2 18650s. Might be smart to specify that to store so they can check..

Very sturdy and pretty cheap

 

[Tomcat!]

I like the idea. Seems promising for making wired external battery packs (headlamps, bike lights, etc). Very clean looking.

For some reason I always thought those keep2go tubes would hold 2 18650s.
https://www.4sevens.com/index.php?cPath=82
I know they can hold 4 cr123s but am not sure if the diameter will accommodate the 18mm diameter cells. Can anyone verify?

This is a yes and no answer. It all depends on which ones you buy. I got an assorted set with all of the colours, and can tell you that the internal dimensions vary. My dark blue tube will fit 2 18650 Pilas (which I believe are a tad fatter than other 18650s) just fine. However they will not go in to the dark green one more than about 10mm so the cell will jam at the top. My 17500s on the other hand will fit nicely into the green one. Some of the tubes taper quite severely near the top so are not suitable for 18650s. I have four colours, dark green, dark blue, light blue and clear. All will take 17500s and 17670s. The dark green and clear tubes will not take 18650s. I've tried them with Pila and AW cells. Other people have noticed the same issue and confirmed the size variation between the colours. [Jump in anybody with a different colour/size combination.]
If you are buying from 4Sevens you could ask him to check the fit first. Hope this helps.

 

[rantanplan]

same experience here: "crystal clear" only fits 16340 (CR123A), light and dark blue tubes can hold two 18650s fine

... these tubes are nice, but still a bit "bulky". I would like to have something smaller for 2 or 4 cells, like a BATUCA BATTERY CASE, but of a bit better quality, maybe with a seal so that it is "water resistant" too ...

 

[alphazeta]

Awesome, thanks for confirming the variation of the inner diameter on those keep2go tubes.

 

[Tomcat!]

same experience here: "crystal clear" only fits 16340 (CR123A), light and dark blue tubes can hold two 18650s fine

... these tubes are nice, but still a bit "bulky". I would like to have something smaller for 2 or 4 cells, like a BATUCA BATTERY CASE, but of a bit better quality, maybe with a seal so that it is "water resistant" too ...

How about going to a hardware/DIY/automotive store and buying lengths of clear PVC tubing of the appropriate bore size. Cut to required length for the number of cells, jam a rubber stopper in one end and glue into place, and just jam a dry stopper in the other end. Presto! The tube will be a lot slimmer than a keep2go, can be made any size you like, make as many as you like and very cheap. Only downside is that it wont be pretty.

 

[grindill]

Yes, I'd seen the keep2go tubes in my searches for a holder. There were a couple of things I didn't like about them which pushed me to make my own. First off I didn't like that they only came in 2x mode. What if I just wanted to carry one spare battery just in case my bike light happened to run out of juice while riding home. No reason to carry two extra batteries. The other thing I didn't like was the screw-on top. this adds extra length to the tube whereas using a cap that slips on over the top keeps the length to a minimum. And one more thing would be that the keep2go tubes would be difficult to modify to make an external battery pack.

So, I guess I just wanted something that I could customize. The keep2go tubes look like a very nice product, it just wasn't for me.

Later

 

[Tomcat!]

Sometimes home brew is the only way to get exactly what you want, the way you want it. Your tubes look really good. Also like they way you've thought this out one jump ahead into potential battery packs.

I was going to go the PVC tube route until I happened to come across some acrylic laboratory bug specimen tubes. They look a lot like your tubes but a bit fatter. They will comfortably take a single 18650 or any cell size below, which is perfect for when I only want one cell. The caps are screw on which means they are quite fat but I can live with that. While double checking my facts before my previous posts I discovered that the bug tube caps are compatible with the Keep2Go so I can either hang a single tube around my neck or backpack, or make a K2G a bit shorter. Caps from 2 or 3 litre soda bottles are compatible with K2G because they are really just industry blanks from which they make soda bottle out of anyway. There's another thread somewhere here that explains all that.

 

[LuxChaser]

FYI
the Coghlans-Waterproof-Plastic-Battery-Tube-Match-Holder--Orange part no. CG8746 going for $1.99 @ lighthound is $0.95 all day everyday at walmart. it's located in the outdoors aisle next to the coleman lanterns. a bit of foam at the bottom of the holder along with some paper wrapped(i used 1/4 of an index card) makes for a happy 18650! no rattle+waterproof = win!

 

[siggy]

I haven't read all the responses so I don't know if mine has been mentioned but what I'm gonna do is go to my local tackle shop (****s or Gander Mtn) and get a plano box the appropriate size with dividers and get some sponges from the dish washing section of the kitchen aisle at Wally World or my nearest grocery store and glue them to the box. Hope this helps.