Suggestions for homemade holder for 18650 cells

[Fallingwater]

I want to run my mp3 player on 18650s. I therefore need a holder, but shops around here don't have holders for this cell format.
I tried cutting up a C-size holder and gluing back together in the appropriate size, but I made a huge mess and it fell apart anyway.

Soldering wires to the cell is not a solution, because I need to be able to use the cells elsewhere, and to replace them as needed.

Any ideas?

 

[sysadmn]

I've used clear plastic tubing from the hardware store. When split, it holds 2 18650 securely in a D host. There's also a size of heater hose that might work. 18mm is .708 inches, so a 3/4" ID hose will rattle a little, and a 5/8" ID is too small unless you split it. If you can find 23/32" you're set!

FWIW, a D is something like 33mm (OD) which is ~1 19/64"; just come close without going over, and wrap it in paper if it rattles. I bought a foot, and used a piece just under 5" so the ends would protrude enough to get the batteries out easily.

Decimal to Fraction
Battery Size

 

[Windscale]

I want to run my mp3 player on 18650s. I therefore need a holder, but shops around here don't have holders for this cell format.
I tried cutting up a C-size holder and gluing back together in the appropriate size, but I made a huge mess and it fell apart anyway.

Soldering wires to the cell is not a solution, because I need to be able to use the cells elsewhere, and to replace them as needed.

Any ideas?

Soldering wires to cells is dangerous. Please consult the battery experts before you do this.

 

[jbierling]

I'm looking for the same thing.

Maybe hack at this?

http://www.dealextreme.com/details.dx/sku.5837

-Joel

 

[Fallingwater]

I managed to build one from parts of the aforementioned C cell holder, two solder wire reels and two releasable fasteners.
Maybe I'll post a few pictures tomorrow, now it's late and I'm off to bed.

 

[jbierling]

Maybe I'll post a few pictures tomorrow, now it's late and I'm off to bed.

If its not too much trouble, I'd like to see some pics

-Joel

 

[Fallingwater]

Heh. Sorry, completely forgot.

Before I post them, a word of warning: as always with my homemade creations, this is a hacked-together monstrosity that follows my philosophy of not giving two hoots about how something looks as long as it performs as desired.
If you do care about looks, you're probably better off not looking at the pictures.

In my search for tube-shaped objects that could hold a 18650 I found two suitable ones: solder wire reels and an old plastic bycicle pump. The tube of the pump was a bit too wide, so I decided to go with the reels.
I dremeled off the round plastic things on the ends of two reels and taped the tubes together.
I got the two terminals off the C cell holder and I used liberal amounts of melt glue to glue the positive one to one end of the tube. I also soldered a clip-on connector to the terminals.
Yes, yes, I know clip-on connectors aren't great for cells that really don't like to be shorted, but I only had those, and I always insulate them when they aren't used anyway.

I then took two releasable fasteners, cut their heads off and glued the heads together. I took the two strips and glued them to the tube, and used a normal non-releasable fastener to secure them in place so that the glue wouldn't be weakened by the movement.



More detail of the two glued heads:



Inserting a cell:



Putting the negative terminal in place:



Everything closed and ready to go:



Sorry for the lousy pictures, but I didn't feel like dragging out the halogen floodlights and tripod.

Future plans include removing the clip-on connector and using a screw-type terminal glued on the positive end (so that the holder can be connected to anything by simply undoing two screws), and using JST or similar connectors whenever I manage to find any at non-preposterous prices.