Help Ultrafire C2 protected batteries don't fit !

So I built my first light.

I got the Ultrafire C2 from DX.

A Nanjg 105A 2.8 H,M,L driver from shiningbeam.

A KD T6 XML 1000 lumen star.

I popped in a freshly charged trustfire 18650 flame and it's to long. It works if I screw both ends of the battery tube in about one turn. I was thinking maybe a spacer or some washers could do the trick. How much shorter are the unprotected cells? Does anybody have any ideas or tricks how to make this work?

Easiest thing to do would be to shorten the springs, both on the driver and on the tailcap. That should buy you a bit more room, although not having any experience with that host it still may not screw down all the way.

I've used that same SB 2.8 driver a bunch, and on a few builds I removed the spring completely and replaced it with a blob of solder tall enough to clear the 7135's.

OK I could desolder the spring in the tailcap trim it and resloder a smaller piece on and I should be in business, great idea. Anybody else?

Make sure the tail switch retaining ring is screwed all the way down.

It is tight it has a monsterous spring. I have had it apart about a dozen times trying to find a different lower profile switch to fit it.

i am coufused about the problem it brings, The C2 can not fit the 18650 at the beginning? and the monster spring show the durable itself and a bad news for DIYer?, Then shorten the batteries! LOL!

That's probably about as small as you want the switch to be to handle the current.

On a protected cell if you look at the bottom end of the cell you will see there are some intentations in the wrapper a couple of millimeters from the bottom, that's the protection circuit.

Here is the problem I have a 12.9 mm switch and a 10.5 mm clearance after subtracting 1 mm for the metal on top of the switch housing.

This battery is the one I use in a solarforce L2i because it is shorter than any other battery I have. Works great.

Thanks Lang, I was hoping for a battery recommendation. I guess I will order 2 of those batteries trim the spring on the driver and replace it with a blob of solder replace the rear spring with a smaller one and that should give me just enough room to get my baby working 100%.

Thanks everyone for all the help, that's what makes this such a great forum.

Over and out E

OK so just for future reference I will give this thread some closure. I did not get the light to work with protected cells, but I found two unprotected trustfire flames that I recieved by accident. So with the spring on the driver removed and replaced with a blob of solder and an unprotected trustfire flame 18650, it fits perfectly and works great. Still not as bright as the manafont drop ins or the KDC8 but it does have a nice hot spot, a really low low, no PWN and I made it myself, so I am pretty happy. Total cost under $25.

It's good to hear you got it working :)

These kits were on sale a couple of weeks ago for six bucks. I bought one and should have bought more. Its a pretty decent light. I put in one of the new KD drivers and an XML of unknown origin. I really like that driver. The kit that I got has a nice plastic isolator disk. Nice touch there. It still will not fit protected batteries but that’s no big deal for me as I rarely use them anymore. If you are looking for a nice little project, even at $12 its a good deal.

You can always put a metallic ring under the pill to screw it down perhaps 1mm less (to preserve heat dissipation) if the head permits. I've done that on a few F15 and all was good. No particular experience with the c2 as i never owned one since i dislike the design.

I got one of the new C2s also I could not resist for $6 bucks. I have not had time to put it together yet, but I did notice it has an improved tail cap similar to a C8 which adds a couple millimeters of clearance for bigger batteries. Other improvements include a plastic isolation disc and a slightly nicer coating.