Convoy C8+ New look for an old favorite

I agree it should have a little more lumens and take bigger batteries wouldnt hurt but i guess since convoy is about budget u cant expect that perhaps idk but then again whats the point calling it + if just the host changed? not much need imo. i have 2 c8 already.

J-dub:
Can Simon make the led shelf thicker? In the old C8 it was only 2mm thick. Nowadays many of us put SST40 leds and fet drivers in these hosts and I will be happier if it will have a 4mm thick shelf. It doesn’t really a big change and it is not even make the machining time longer. It even make it shorter as you need to remove less material from driver side.
The old shelf can handle well the stock 2,8A current but with 6-8A it will be better with more mass. Also like the 21700 battery idea.

I’m thinking maybe around $30?

http://www.kaidomain.com/p/S027411.KDLITKER-C8_2-Cree-XHP35-HI-Neutral-White-5000K-2000-Lumens-5-Mode-LED-Flashlight-Black

Nice! I wonder if that is really 2000 lumens, or somewhat exaggerated. Anyone know?

If it’s putting 1500mA into that LED, it might be 2000 lumens.

If that’s the light I think it is my buddy in H town got one and it was quite a bit short of the advertised lumens.

Edit: With the 12V emitter a single cell has to be boosted 3x and then some, so if the limit is 1500mA then the 35 isn’t going to do all that much more lumens than a well driven XP-L HI. Current overall will end up very comparable.

1500mA is overdriving the 12v XHP35, but it should be do-able with good heat-sinking. The XHP35 is more efficient than an XP-L. It might produce 2000 lumens at that current, but I’m not sure. The XHP35 HI, perhaps not.

But, yeah, specs are often over-stated, so 2000 lumens has me suspicious.

I thought the XHP35 HI had a slightly different beam (a bit more spill) than XP-L HI?

I also thought it used less current than XP-L HI to produce similar output, in other words I thought an XP-L HI had to be driven harder to produce the same output as an XHP35 HI, and thus XHP35 HI is more efficient?

Looking at these (Mfg. Specs) below there isn’t much difference in output/throw. Is there any reason to use an XHP35 HI at all? Why is Thrunite and Utorch using it for their single cell throwers instead of XP-L HI?

Emisar D1S…………18650…………XPL-HI…………1300lm……………720m
Maeerxu M8…………26650……….XPL-HI…………1200lm……………800m
Utorch UT02……….26650……….XHP-35 HI………1300lm……………700m
Catapault V6……….26650……….XHP-35 HI………1700lm……………750m

I need to learn about this because I had been planning on modding a single cell light with XHP35 HI instead of XP-L HI because I understood it would have slightly more spill and slightly higher lumen output, using less current from the cell.

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The efficiency I was basing from the Cree specs:

Cree Data:

XP-L High
Maximum Drive Current………3 A
Max Power (W)………………10 W
Max Light Output…………….1095 lm

XHP35 High
Maximum Drive Current…….1.05 A
Max Power (W)………………13 W
Max Light Output…………….1483 lm

The XHP-35 can make around 2500-2600 lumens at 2.5A-2.8A, will burn up somewhere North of 3A usually. Anything over 2.5A or so is typically just making more heat without making noticeably more lumens.

The XP-L HI can do around 6.5-6.7A and make up to 1700-1800 lumens. It’s forward Voltage will limit it on a single cell so that it will not burn up.

So if you look at what the single cell from a boost driver is actually being asked to provide, the current from the cell is upwards of 4.5A or more, the driver itself producing heat to go along with the pushed emitter. You’re really not gaining much going 12V XHP-35 on a single cell. That’s what I find in the lights I’ve looked at. Most boost drivers won’t push the 35 to 2.5A from a single cell, so it’s lumens is down around where the XP-L HI is, begins to look like a lot of work to get back to where we started…

Spec sheets? Do we use those here?

BeamO:
The UT02 putting out a pathetic 900 lumens in real world in stock. But the Emisar D1S putting out about 1500 lumens stock. See my measurement google tables. You will fi d various flashlights with a lot of led type and beamshots.

XHP35 will rock once GXB172 or Shocki’s boost driver are out. Which can happen at any time…either close or far, they are a quarter late already.

Thanks, so if I understand correctly this is current draw at the emitter not current draw from the cell? And when the emitter pulls this current, the boost driver is actually pulling nearly twice that from the cell?

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It was all I could find to see the numbers. :person_facepalming: I guess I need to ignore those cree specs and look at real specs here like ZozzV6’s measurement tables.

Thanks I didn’t know! You’re tables are a great reference I should have been looking at.

It really looks like the SST40 dedomed comes out on top over both XHP35 HI and XP-L HI, so I have to also consider that emitter for my mod.

I don’t. I use the CREE PCT. And what I find is that counting the LED only, the highest bin XHP-35 HI is more efficient than the highest bin XP-L HI along its entire rated range. The needed boost driver would have to be less efficient in order for the flashlight to end up less efficient. I thought it’s been said that a boost circuit is more efficient because it’s using the whole voltage output of the cell instead of burning up the voltage difference from the cell to the emitter like linear drivers do. But, I don’t know. Just going off what’s been said around here. I’m curious how real life differs from these widely held BLF beliefs. You mentioned heat, but I’m just looking at efficiency as power in, light out. Heat just makes up the difference in lost power.

In reference to what Dale wrote (post #43 above) how will this new boost driver make the XHP-35 HI an advantage over a FET driven XP-L HI?

Does the PCT go to 2.5A for the XHP-35?

Does the PCT go to 6.6A for the XP-L HI?

If not, on either one, the efficiency numbers are skewed.

The boost driver is converting the ~4V of a single Li-ion cell to ~13V for the 12V rated emitter, so it’s more like 3x or a little more when the cell is fresh. When the cell is dying the driver is pulling even higher amperage to convert 3A to that same 13ish. So the boost driver will pull 5-6A on a fresh cell and up to 9A or more as it dies, that is of course if it’s a regulated boost.

Our FET Direct Drive drivers are very efficient at Turbo as they are virtually direct off the cell, again though we have to consider how far over rated max the emitter is being pushed to get an idea how much more heat it’s making and what that might be doing to the emitter and it’s output. The FET driver doesn’t make heat on it’s own, whereas the Boost circuit does. So that is added into the equation as well.

In the end, if a FET driver is used with an XP-L emitter (HI or otherwise) the output is close enough to the XHP-35 at reduced current levels (those the single cell boost drivers are capable of achieving) that it’s really a waste of money to go with the more complicated circuit.

The SST-40 from Luminus is another not very efficient driver, although it IS capable of 2600+ lumens and from a single cell with an FET driver, the downside to this one to date is the limited tint availability, only available in a blue-white cool tint so far. It’s capable of hitting the cell for 9.8A or so to make the big lumens, so yeah, there’s a lot of heat going on there as well.

Richard worked very hard to make a 17mm boost driver happen, but it just isn’t feasible at that size as it can’t make the 2.5A optimum current requirement for the XHP-35, get’s hot and acts wonky, ends up failing in the long run if pushed that hard. So it’s expensive, difficult to pull off, and the gain is a mere 500 or so lumens IF you can get it work. The XP-L2 is capable of 2300 lumens on the FET driver/single cell configuration so there go the XHP-35’s advantages…

Now, if you’re going to run 4 18650’s in series and Buck the current down to the XHP-35, then the lumens output makes it worthwhile and the throw stays high while adding in a larger hot spot. A clean de-domed XM-L2 will best the 35 in throw, with a considerable lumens disadvantage. So it’s again about compromise and trade-offs.

The UTorch UT02 lights are a good example, using a 26650 cell they still can’t get the driver to boost decent current to the 35 without overheating. They’re giving around 1300 lumens in stock form these days. I pulled the 35 and piggybacked an FET+1 With Anduril running an XP-L HI and am getting 1700 honest lumens for over 200Kcd throw, much mo bettah! :smiley:

Perhaps those new highly touted boost drivers are over a quarter late already for a reason? :wink:

If we could run with a 22mm or 26mm driver, then larger and better components can be used and it might just work, the driver ends up in the $25 range instead of $5 or 6 but there it is, gotta pay to play.

For the record beam0, I have an XP-L HI V3 3A running 6.4A and making 1538 lumens for 1.05Mcd…. from a single 32650 cell.

Yes, that’s 1,050,000 candela, as measured at 50M.

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: