XHP-35

Very nice indeed! :bigsmile: Will you be creating a build thread for this one?

Just got lux readings, mind you I didn’t bother to charge the little 18500’s first….

331.75Kcd for 1151.96M throw, and I haven’t even fine tuned the focus! This reflector has a wide base, I’m using a 20mm Noctigon at the moment, so I can’t get the reflector to sit down on the mcpcb like the HI series seems to prefer. I’ve got a ring showing from the thickness of the reflector at the emitter opening, but all in all it’s pretty amazing for this kind of die! It acts like a much smaller die surface actually. I’m impressed where I was expecting to be disappointed.

I didn’t take pics along the way or anything, went out of town today and came home to find the components I needed to modify the LD-2 had arrived in the mail, jumped on it and got it done after figuring out how to re-flow this odd emitter.

Remember DO NOT GO BY THE BOND WIRES! Reflow it according to the anode mark on the base. (Actually the thermal pad has a triangular cut out on the anode side)

Which XHP-35? HI or HD and bin?

HI, the first one’s Mouser had, they were on order and just came in the other day.

941-XHP35AH10D0BC4E3
XHP35A-H1-0000-0D0BC40E3
Neutral White, 475lm

I pulled the 20mm Noctigon and used a 32mm Noctigon soldered to a copper disc of the same thickness. So now the HI sits on 1/4” of copper that fills the pill of the light. Took a little trial and error to get the nice hot spot back but in the end I got it. And the base of the reflector sits higher than I would have figured, with this reflector anyway.

This 5000K is a nice white with a hint of the warm side. Crazy that the hot spot is so unified, no sign of it being 4 dies whatsoever.

XHP35 HI C4
Comparing results from this thread and what is available on CREE PTC.
VOB 2.5A - 1370 lumens
Dale 2.39A - 2018 lumens

Dale 0.48A - 648.6 lumens

CREE PTC 50C 0.45A - 633 lumens

It looks Dale's number are kind of matching CREE's at around 0.45A current and 50C, not using the unrealistic 25C numbers which generally are used.



LOL well I have to say that's a little embarrassing. It may well be that I am further out of calibration than I though when using the bare emitter on a slug.

Althought the lux testing I did had nothing to do with this. I still got nearly identical from the de-domed XML2 U4 as I did from the XHP-35


Dale are you using a sphere or one of the light pipes? Did you have to make any adjustment to your divide by for this test?



I'm not really sure yet. The fact remains it does have an amazing beam. Nice hot spot and good throw, I guess I was just expecting a lot more is all.

VOB, the more data from more people the better.

Maybe you guys can accurately measure the die (the multi-de) size of the XHP35, it is exactly XM-L2 size or bigger?

It’s easy to know what twice the lumens is going to look like. Take a second identical light, point it at the same spot and turn it on. To me, it’s never an “OMG” difference, but it is a difference. It is easy to have too high of an expectation and if that is the case, it is easy to be dissappointed. Nevertheless, the XP35 will be a lot brighter, go for it!

I know that second identical light test sounds obvious, but how many have never thought of doing that?



I get about .105" (2.66mm)with my calipers for the total die size of the XHP-35.

i paused my MM18 review and try to test my xhp35 in my lightbox at different amps…

since i have no adjustable power supply i think i try to DD it with different length and thickness cables :wink:

my setup seems to read too high i am afraid ( a 1000 lumen Fenix gets around 1200 in there)
a quick test of the xhp35 showed near 3k Lm @2.5 A
(–20% = 2400 Lm which is still good)

Thanks, that means a larger die size than XM-L (2mm)

Measuring a mule is ALWAYS going to be much different than measuring a thoroughbred.

The reflector collimating output makes all the difference in the world in how the sphere or lightbox reads the result.

I use a light pipe as built and calibrated by manxbuggy1 and rdrfronty. They used 20 something ANSI lights to determine the multiplier, which for me is .345 x the meter reading. If I have to figure anything and shift or make adjustments, then the game is over and they’ve already turned the lights off cause that ain’t happening! :stuck_out_tongue:

Yes, these measurements are in a built light, I should have gotten beam shots last night but was exhausted after a very long and hot day out and about.

PS: Let me also add that holding a Couri D01 reflector over this emitter gives spectacular results with an even tighter hot spot and very smooth spill. :wink:

VOB,did you drive led with some current source,or did you adjust pwm of DD driver for each current?

Well - i have some numbers...

my not scientific "setup" (man! - i really need a 30/20 bench power supply....)

i used several cells in 3S and 4S to simulate different input voltages (due to sag)

(the 3,3A could only be reached with full HE2)

i think my "lightbox" given readings are about 15-20% high (1000 Fenix-Lumens are displayed as ~1200)

Volt mA "Lumen"
10,5 19 43
11,03 110 263
11,95 520 1050
12 590 1170
12,12 620 1250
13,7 1700 2560
13,9 1900 2700
14,12 2230 2900
14,5 2500 3000
14,9 2700 3100
15,2 2980 3200
15,8 3300 2800

as Graph:

Volts from left to right are meassured at the cells

numbers are taken after 10 seconds (fast drop due to heat above 2 A !)

i let the LED and copper heatsink cool down to ~25° after each meassurement

i tried severall cables and even SMD resistors (holding by hand between the contacts) so get Amp-readings around 2A - but i ran out of time.

i think led4power guesstimated the sweet spot at 2.5A just perfect ;)




I have a mastech bench power supply.

Right now I have a U4 XML2 in the gas for de-doming. Tomorrow I will run this in my setup and see what I get apples to apples. I will do a test both on a copper sink and inside identical lights.




FWIW, the light I used is a Maxtoch SN50. The Luminus SST-50 had to go, of course, and I had already put an SST-90 in it. This Cree XHP-35 is tighter, whiter, and more powerful and probably a good deal more efficient. :wink:

Edit: Beamshots…

First, a comparison shot… my EDC Eagle Eye X6 Triple with V2 1A XP-L HI emitters and a polished CUTE-3 optic…

And the same scene, same settings, with the Maxtoch SN50 and XHP35, using LED4POWER’s LD-2

The above 2 shots were at 28mm, here’s the XHP-35 zoomed in to 112mm for detail…

And aimed at a little barn 610 yds away, first at 28mm then at 112mm

Works for me! :slight_smile:

Oh yeah, forgot to say… the X6 Triple is making ~3880 lumens while the SN50 XHP-35 is doing 2060.

I can’t believe the beam this XHP-35 is making, this isn’t exactly the best host for this but it’s still pretty dang nice, I can only imagine it being that much better in a bigger better reflector.

has anyone a word to my results?

M4D M4X, looks like you did a fairly exhaustive testing set on this and other than the lumens reading on the high side it all looks fabulous! I wish I could chart like that! :slight_smile:

Did you get the lumens numbers with the emitter in a light? Or how did you derive those? Do you use a lightbox or sphere? Curious, is all.

I used the components Neven suggested, except for the resistor at the moon set, I didn’t have the correct one and frankly I don’t like a super low moon on a light like the SN50 anyway. So the 32 lumen moon is fine with me. I used a 270Ohm in place of the 154Ohm.

I stacked 3 (I think, 2 tall and 1 beside em laying on it’s side) of the 750KOhm resistors at the battery set-up side and engaged the 2 cell button. Then, with a 180KOhm sense resistor (I had already pulled the stock one, so I put on a new one) and the new big resistor at 2M instead of 1M, I got really close in-light reading’s to what was expected. I didn’t want to push it REALLY hard, but wanted it up there fairly close to top end. So far so good. I’ve run the light 5-10 minutes at a time and it seems just fine. When all was done with the assembly and I was happy with it, I smothered the inside of the board with Arctic Alumina Thermal Adhesive and topped it with a new 16mm Noctigon, masked side out. The driver itself is soldered into a thick copper disc (same thickness as a Noctigon), as this light requires like a 24mm driver (didn’t measure, just cut to fit) so the driver has heat sinking through the thick copper adapter it’s soldered to, which in turn is clamped into the lights heavy pill with a thick brass retaining ring.

I have no idea if all that will help anything, but it occurred to me to give it the benefit of doubt and add that copper for a bit of a sink. Whatever, it’s working and I’m very pleased with it.

The light has a 3 cell tube, so 4 18500’s fit nicely. I don’t know what it’ll do with hotter cells, but you’re showing the best output from HE-2 or HE-4 cells. Are we giving it too much Voltage with 4 big dog cells? That’s what I was afraid of, so I went with the Sanyo lap pulls. Figured they’d sag pretty much at load and then be within reasonable realms for this modification.