Convoy C8+ New look for an old favorite

Much higher output, somewhat higher throw, much higher efficacy (lm/W). And fully regulated boost allowing it to get full output from half-discharged cell.
You pay for that with much lower throw-efficiency (cd/W), higher price, larger drivers and worse driver availability.

Come on, don’t compare XHP35 HI to XP-L2.
Lumens may be similar, but the latter has terrible tint and doesn’t throw.

BTW, I wouldn’t drive XHP35 to 2.5A in any of the hosts discussed in this topic. I’d rather do 2.1-2.3.

XHP35 is Pareto optimal in throw vs. output. And by a large margin. You can best it in either, but by sacrificing disproportionally lot of the latter. It is also quite efficient from medium currents up, has good tints and doesn’t require dedoming. They only drawback is that it’s 12V.
And I can’t stop thinking that with a larger package and better thermal path it would be even more awesome…

Maybe. I don’t know. Lone Oceans has shown his driver to output more power than XHP35 can take, so maybe not.
Anyway, I stopped holding my breath. :weary:

I didn’t think such currents were possible with XP-L HI and FET.
According to Texas Ace that’s over 4.08 Vf.
Did you win the Vf lottery or did Texas Ace lose it?

Anyway, that “higher throw” of XHP35 HI that I wrote above doesn’t seem right now. In a low resistance host, with a powerful cell XP-L HI might offer a bit better throw.

Wow over one million candela! I assume it has a jumbo size reflector?

Thanks for all the info and explanation, it was going to be considerable hassle and extra cost involved in trying to use the XHP35 HI, so I’m going to take your advice and keep it simple with an XP-L HI and FET driver.

Since you mentioned it, I remember now it was the larger hot spot (not more spill) that had my interest in the XHP35 HI, which would be nice. But even though I do have a 20mm driver space, after reading all this I see it’s still isn’t worth chasing after the 12V emitter. I’m happy this got sorted out before I ordered any parts.

I guess because there’s so many newer production lights using XHP35’s that had me thinking it was the better way to go. The XHP35 C8’s from Kai reportedly get hot quite fast compared to their XHP50.2 version C8’s, now I understand why.

My lights that use XHP35 HI put out about the same lumens as a FET-driven XP-L HI, but they can do it fully-regulated. My XP-L FET lights suck when the battery gets about 50% drained, whereas my boost-driver XHP35 lights still have their full output.

For example, my Zebralight that uses XHP35 HI will provide full maximum output until the battery voltage drops to about 2.9v, which is almost its entire capacity. Also, since I don’t think Zebralight overdrive’s it, it’s more efficient.

So, I think there are advantages to using an XHP35 HI with a boost driver, even if it’s not any brighter than a XP-L HI with a FET driver.

That’s what I was thinking would be the case. I don’t have either in a light right now, so I can’t compare. But, I can’t imagine the XHP-35 HI would ever switch over from being more efficient than the XP-L HI to being less efficient than the XP-L HI just because you go past the CREE max current rating. Both of them will lose efficiency, but the XHP-35 HI should still always be the more efficient of the two.

The emitter will be more efficient. But the emitter-driver combo?
At high current GXB172 is 90% efficient.
At high current FET driver is nearly 100% efficient.
Now, if we’re talking driving lights with a fresh powerful batteries (and that’s what most of this topic is about), XP-L HI V3 driven to mere 5A does 1500 lm with 80 lm/W.
XHP35 HI E2 is doing the same 1500 lm has 120 lm/W. Drop it by 10%, it’s still much better.
With higher currents the difference will be larger.
So with a weak or not-fully-charged cell XP-L HI may be more efficient. Or maybe not….
At high current….not really.

beam0, you can use an XP-L HD (dome on) and get a larger hot spot if throw isn’t everything, which it really can’t be in a light the size of the C8 anyway.

I didn’t like the ringy beam profile in my ArmyTek Barracuda Pro with XHP-35 HI, for example. So I put an HD variant in it and it’s got a very nice beam profile now.

Zebralights are so cheap, think I’ll pick up a few of em and try em out…. (NOT!) :stuck_out_tongue: So yeah, regulated gives the full output level til the cell dies, but what does that do in the long run to the cell? And you get so little warning before it shuts down, at any rate, compromise rears it’s ugly head…

Put an XM-L2 U4 in the C8+, the lower forward Voltage will keep the FET from allowing too much current draw while it still gives out a lot of light, run time is longer, output is similar, large hot spot for a great general purpose light. :wink:

(Edit, 114 lumens per watt vs 109 lumens per watt, are those few lumens difference really worth worrying about? You can’t see 50 lumens difference on the top end anyway.)
(Edit II, what makes the difference for me isn’t efficiency or sheer lumens, it’s the available UI. I can use the FET+1 and TK’s firmware and have a UI that can back up, not go through all the modes but reverse back down to lower modes and conserve the cell when Turbo isn’t needed. That ability, start on moon and long press for Turbo, that is the game changer as far as I am concerned and it’s why I don’t use a boost circuit… even why I use TK’s FET set-up in lights that came with a boost/35 to begin with.)

Dale, the single cell light I’m modding isn’t a C8, but it is an old favorite, an original UltraFire HD2010, which already has pretty amazing throw for having an outdated emitter (XML T6) with east-092 driver (DD but crappy mode arrangement)

I have one of these copper pills:

Takes up to a 26mm MCPCB, and a 22mm linear/FET driver.
I plan to use a Maxtoch XP 26mm Copper MCPCB to keep the wires away from shorting on the reflector.

And yes throw isn’t everything in my plans for it, I want good throw, but with some useful spill / larger hot spot / extra output.

It’s one of my favorite lights and one of my first purchases when I got into this, and I’d like to make it into something special and useful, so I thought it would be a good candidate for an XHP35 HI, don’t want to derail too much here but I’d love to hear any other suggestions.

I’m also considering an XP-L2 HD (dome on) I have a few (stock) lights equipped with it and the tint looks fine to me.

I’d use an FET driver from Richard paired with an SST-40, I think. That is a good combination for this C8+ or the HD2010 either one, where the parameters are as you outlined. I think I’d use thermal paste to begin with, try it out, and if the spot was too large I’d pull the pill and remove the emitter then slice/dice/shave the SST-40. Would probably re-flow the emitter/mcpcb into the pill then, might would reinstall it with thermal paste and double check first but I’d probably go straight to the re-flow. (test it first, make sure it isn’t ringy and that it’s to your satisfaction, then go from there.)

Thanks, then I’ll use a MTN-22DDm.

Versus using only thermal paste, what does reflowing the mcpcb to the pill result in? Better heat dissipation?

I had thought about the SST40 but wasn’t sure I’d be okay with the tint since I’m pretty firm on neutral tints only, and everyone seems to comment on how cold/bluish it is, interestingly just today I received my first SST40 light! (Jetbeam E20R). I wasn’t able to get outside with it tonight but inside it’s not too horrible, I don’t see any bluish tint at all, even on white walls, it looks very yellowish to me, with a hint of green.

I also plan to get the C8+ tan host version and run a MTN-17DDm so maybe the SST40 for it as well. I see Richard offers the Slice LED option, how’s the tint on it after slicing?

The SST-40 doesn’t exhibit the tint shift we’re used to seeing from Cree, it does drop some but not like the XM-L2’s. I’ve found the 40 to have a nice creamy color once the dome is taken off. Richard seals them though, so it’s a bit different than a naked die.

Does anybody know if the old bezel ring will fit to the new C8+?

I saw a picture of a C8+ with stainless bezel so yes.

But what about a nude gnu?

Thanks, curious though now to see that photo :slight_smile: (no luck with google etc.)

Gnude Gnu’s haven’t been legalized for power use to date, not in the US anyway. Testing is underway to put them to work under AR confinement but the results are not in… Gnarly Gnude Gnu’s will be next. Mark my words. :wink:

I only asked because you mentioned creamy colors and naked dies. :innocent:

Naked makes news, always! :slight_smile:

Still though, it’s true, the XM-L2 U4 with a clean de-dome on it throws further and burns less current than a pushed XP-L HI, MaxToch found that out in the Shooter 2X.

Found it. It was in a facebook flashlight group.

Thanks Zozz, a small gap but it looks pretty good!