Ultrafire C1 Direct Drive

I just got my new Ultrafire C1 R2-WC from DX and am not happy about the output of the light.
http://www.dealextreme.com/details.dx/sku.14601


Here are the output results on my meter:

TEST MODE BATTERY VOLTS AMPS OUTPUT
High with CKT TR18650 3.7 0.26 0.962
Medium with CKT TR18650 3.7 0.13 0.481
Low with CKT TR18650 3.7 0.06 0.222
Direct to LED TR18650 3.7 0.65 2.405

The light is running the Cree R2-WC LED
http://www.dealextreme.com/details.dx/sku.14442

This light seems to be way under powered when compared to my Ultrafire C3 running on a single AA battery. A ceiling bounce test showed a lot more light coming out of the C3 than the larger C1. My meter tests confirm I am getting more output.

TEST MODE BATTERY VOLTS AMPS WATTS OUTPUT
High with CKT 1xAA 1.32 0.92 1.2144
Medium with CKT 1xAA 1.32 0.67 0.8844
Low with CKT 1xAA 1.32 0.3 0.396


I am thinking about running the light direct off the battery to get the most juice to the LED. I have read on some other threads that this could lead to "thermal meltdown", where as the LED heats more current is drawn which in turn heats up faster...starting a cycle that burns out the LED.

My observations start at the fact that most of the other Direct Drive posts show a much higher amerage on the direct drive, where mine is still only down arout 650mA (which according to the specs on the website, is still way under the 1000mA rating the light has from factory) (which it clearly is not getting).

Also what is the danger to the batteries? I am running the protected TR18650's and don't want to damage the batteries.

Well, I gone and done it. I wired up the light as a direct drive system. It sho-is-bright now. A little pocket rocket. Figure that I can always replace the LED pretty cheaply and will try to use the same battery always. If I get trouble with the battery, that will be replaced too.

Here is some more info on my mods. Quick and dirty.

This is the base package that I started with. The smaller Ultrafire C3 was initially brighter than the larger C1.


Here is a close up on the original Cree RC-W2 LED emitter. You can see that they used very small wires to connect the positive and negative terminals.


Here is my modification. I used a very small drill bit and drilled down from the top, through the LED. Then also from the bottom of the LED, I drilled through the circuit board. This gave a nice little hole going from the bottom up to the LED on top.

Afterwards, I used a boat-load of solder to join my positive wire to the center of the circuit board on the bottom where the spring joined. On the right side picture, that large blop of solder runs right into the solder holding the spring to the circuit board. (The spring did pop off during the process and I just added more solder to get it back onto the center of the board.) I didn't have any red wire on hand, but the wire I did have was a pretty thick guage when compared to the wire that came with the LED. After I finished soldering, I used a dremmel to file down the solder joing on the top of the LED as the aluminum cone wouldn't screw in all the way. Now the LED sits in nice and deep and I have a good spill pattern.



I don't have any pre/post pics to compare on the output, but it did increase dramatically. I had tried my light in the back yard and pre-mod it was usable to about 80 ft (my back porch to the tool shed). After that range it was pretty weak. Now I can light up a good 50% farther. The beam isn't as focused as the WF-600 Thrower, but it is more compareable in power to that one now.

No idea on how long the LED is going to last, but I have other lights. I was looking forward to having a little pocket cannon. This has been really fun to mod and play with. You can tell you are getting to be a flashoholic when you get excited about increasing the performance of you light by 40%. (Yes - I need to improve my soldering skills. Please don't hate on my for the crappy joints.)

I know old post, but wondering how your light is holding up. I'm ordering one of these, even though I see everywhere it has horrible performance stock. My intent is to mod the crap out of it. I just don't know whether to get a current regulating circuit board or just DD it with a resistor. how is it holding up with DD and 18650 blue tape?

The light has worked great. I don't use it every day now, but I did use it quite a bit over the winter. Never had any issues with the direct drive (wiring the LED to the batteries). The light is quite a bit brighter than when it came from the factory and I never had problems with it.

The 18650 blue batteries I use seem to work pretty well. I don't have any good quality AW's in 18650 to compare. I do have both in the CR123A and the AW batteries are much better, but I haven't had any problems with the blues in my C1. Even now with the light pulling double the juice, it is holding up well.

I carried the light as a tactical pocket light. I realized that when I am carrying with this in mind, I don't want to be messing around with different brightnesses. If I pull this out while on a walk (against a dog or person) I want max brightness with one push and nothing else involved. If I want to read at night or be more discreet, then I have other choices. (I currently have it mounted on my rifle and it seems to be very happy there).

Good luck with your mod. I'm happy with mine.

Hmm got the same light in my car and also another one with p60 drop-in, and when i was measuring current i also figured out that it was only pulling ~650mA...Way too low for a cree in my opionion, so i think i'm going to have a look for a simple + fitting driver...

I wouldn't even worry about a driver. No problems for about a year on mine direct. They are pretty cheap. If it burns out, then look for a replacement.

I dd'd one of my cheap drop-ins for this light off of DX, little apparent difference, doesn't seem any less stable either.