Triple XP-L Convoy S2 MTN Edition BLF17DD Review

I tried to put solder paste on the threads, figuring to reflow it together. I couldn’t get it to thread or screw in with the paste on there. Probably would have been a PITA to keep all the wires in place. It took a long time to clean out with an old tooth brush and paper towels.

Is it worth running a triple xpl on a sensible current that would allow you to run it constantly without heat issues in an Convoy S host? How much current would that be and what output would we be expecting? I like the setup but always prefer to have safe runtime on a high mode and then all-out turbo with stepdown.

aoeu, it might be worth looking into as the Cree datasheet shows a more efficient 350mA to be an ideal. So if 1A or a little more were provided to the 3 XP-L’s then the triple should be in an ideal working range. This could, of course, be configured into the UI at the second or third level to offer a choice of efficiency, while maintaining a more robust high and 100% turbo. (can’t give up the all out blast of awesomeness!) :slight_smile:

I would think output would be in the 500-600 lumen range at those levels.

Thankyou I checked it out. Seems you do get a ~20% advantage from driving same current through 3 XP-L than that current through one XML. I suppose that would mean the triple would produce less heat with the same current and lumens?

Okay, wait. You’re saying that thermal paste, something that is supposedly made for helping to conduct heat between two surfaces, is just barely better at conducting heat than air? That is hard for me to understand. According to Engineering Toolbox, even Styrofoam (made to NOT conduct heat) conducts heat better than air. Plain ole Epoxy has a thermal conductivity that is almost 15 times that of air. Insulating brick (didn’t know that existed) conducts heat at a rate 6.25 times that of air. Yes, these are still relatively tiny amounts, because the only thing that air conducts heat better than is a vacuum. But, we’re talking about thermal paste. It should be pretty good, I’d think, at doing what it was made for - especially compared to leaving the air void that would be there if the paste wasn’t!

edit: to clarify, there are several gases on the list that are less heat conductive than the air we breathe, but I call them all ‘air’ for the purpose of these comparisons.

David, for me it’s a moot point…2 bare pieces of metal in contact with each other will conduct heat between each other. period. Are there microscopic gaps that hold air at the junction? Most assuredly. It becomes a matter of quantity I would think. Microscopic air gaps between surface contact leave how much percentage of contact at a loss? Can’t be much, if the gaps are microscopic in nature, right?

It’s really a question of efficiency, and the effort to increase efficiency might be more than the net gain in these applications. We struggle to max out the emitter performance, while the cell sags and loses power…effectively killing all of our efforts in the first half minute anyway. Vicious circles.

The bigger point is that if the thermal paste is not applied as it was intended then it could be more detrimental than beneficial. The idea is to fill the air gaps and leave the metal to metal contact. By using too much, you separate the metal to metal and only have paste…losing more than you gain.

I saw someone recommend applying the paste to each surface and then scraping the surface clean of paste with a razor blade. The two surfaces would then mate with the best possible contact.

Almost all of these considerations are extreme examples of taking things to the Nth degree. Something we’re getting pretty good at in our search for flashlight Nirvana. :wink:

I keep saying we need ray-gun-type cooling fins.
I just found the ideal hardware to mod with the latest, hottest emitter:

Uh, yeah, it needs some work:

Yes, that's exactly what I'm saying. Your ideal insulator, styrofoam, could very well be a very good conductor at a thickness of 1-3 microns.

edit: And this is why these reference charts are misleading at best. You have to know how to interpret the data as it applies to a specific situation, and if you don't know how to do that, you'll think you understand something you really don't.

what is that?

what kind of wires you used for this triple ? 18-20awg?

You know I have no idea. Whatever wires rmm connects to the blf17dd

Should be 22AWG.

i assumed that for 10Amps you will needed thicker wires .

3000+ lumens on a single 18650 EDC format light?! Me likey :open_mouth:

How many lumens could you get with only 3 amps driving this?

You know it’s not clear, but 10 amps is really great

At 4.0v and a distance of less than 3 inches, 22AWG will carry close to 20A, assuming 5% loss

Bort, that was an attempt at humor, about cooling fins: the link is to http://www.rayguns-r-us.com/

It was a rare non attempt at humour, it just looks futuristic, thanks for the link, i thought it might have been the gun marvin the martian used.

i just built one of these lights and i get 6.2a with a blf17dd and sony vtc5. does anyone else get more?? i would like 10a. lol maybe il try changing the standard wires to 18 gauge.