Finally the XHP70.2 emerges!

I have seen just over 22amps with the SD75 board on the sink directly hooked up to a 2S2P battery carrier with 4 VTC5a’s, and it still works, so a 2S set up might be the way to go, until somebody tests it, no sense running it past it’s useful out put. The heat this thing throws off is amazing, the host might be getting hot fast, wonder how hot the board is getting?

Notice I kapton taped the heck out of it, wasn’t worried about shorting off the reflector, machined the reflector so I have plenty of clearance, just that red wire de-soldering itself :person_facepalming:

Better to error on the side of safety, I guess, it is a beast of an emitter that’s for sure!

It is also the only thing stopping me (2S2P carrier) from putting this emitter in this thing, Beast Light needs a Beast emitter! :frowning:

Is someone able to mod a Acebeam K60 with driver mod and XHP70.2.

And has someone a power supply witH 20A to test the LED and measure Lumens.

I have been wanting to test the 50.2 and 70.2 for awhile but just have not been able to free up the funds to get my hands on them. I think djozz mentioned he was thinking about testing them, don’t remember if he is or not though.

I got bored so I did a few non scientific/ professional tests.Checked a few 2S 26650 and 20700 battery set’s in the JX6Hunter 70.2 P2-1A

All straight off the charger at 4.20v

KP26650 15.15a

Basen I 16.20a

PEfest 4200 16.65a

Basen II 16.70a

Sanyo 2700A 19.70a

IJoy 2700 20.20a

Topped them off again, and I measured LUX at 2M just to see “IF” it made a difference in LUX readings, just to check the out put in my light with bypassed tail cap. And to see if LUX topped out in between? It didn’t, not from my very rough checks!

KP’s measured 38,000lux

Basen II/ Purple Efest4200’s 44,400lux

IJoy’s measured 51,500lux

Even at 20 amps the LED did not turn blue, pretty amazing! :person_facepalming:

20 amps is basically the same as 10 amps to an XP-L2, which from my own testing, it can handle.

So the real issue is heat, at over 125W worth of heat, it is pretty insane for almost any host. Particularly for the amount of light you get. An XHP70 can make around 6500-7000 lumens and only needs about 80W to do it.

The real benefit is the higher efficiency at lower outputs. It should work great with buck drivers, although they will most likely need to be run in 12V mode to keep the amperage down. For example the GT driver should work great with the xhp70.2 in 12V mode (or 50.2 for that matter)

The "lux" numbers are all directly off the meter at 2m? So x4 for converting to candela, so 44,400 lux is 178 kcd. Think that's about right compared to mine. You have an L6 SMO reflector in that light, I believe what you said earlier?

This is good cause it indicates at 18A to 20A, throw, and therefore lumens, is still rising, at least initially assuming you are taking readings at 30 secs or so.

Thanks for the info!
I assume this was in a flashlight host, right? No big heatsink and fan cooling?

If so, these lux measurements you took were probably within a few seconds of turning it on right?
Unless you had the LED cooled extremely well, the output will drop dramatically the hotter it gets, because a flashlight host sucks for dissipating heat.
Most people wait for the output and heat to stabilize before recording the numbers, which usually takes ~30sec.

Correct Tom, on all counts, Same light I posted. Reflector on the board no centering ring, the L6 smooth reflector center’s up nicely in the X6.

I was just looking to see where this LED might plane or stabilize. I moved it around till I got the best/highest LUX reading, just off center, then held it there, plus what it took for my eyes to adjust to the initial blast at 2m, to see the meter, then my normal count of 10 seconds more or less? I wasn’t concerned with ANSI testing, just give it some time to stabilize.

Bottom Line from what I witnessed, is the emitter IS making more Lumens/LUX at 20AMPS then at 15amps. Regardless of anything else, I’m not that Highly Testicle when it comes to flashlights, I’m happy as hell if it turns on! :smiley:

That is T/A’s and Djozz’s GIG! :+1:

I did change the reflector out to the L6 OP reflector tonight and the beam is rather quite nice, very smooth, and floody, I personally prefer it over the smooth.

It sounds like a 26mm or 30mm copper DTP star combined with machining the flashlight head to match might be a good option with this emitter.

Also Narsil, so you can ramp it down just slightly for more practical usage and longer run times (thermally limited).

Your welcome! :+1:
Yep, the X6 has a brass pill, I bored it out and pressed a copper plug into it, machine the surface flat and then soldered the 32mm Maxtoch DTP board on it. Not much room for the driver. Soldered up the threads on the pill and used the host to re-cut them, it’s a pretty tight pitch now.

I’m not most people and I could give less then a shit what anybody else thinks, my test were not for techies,pros or gurus, just for my own experience and out of boredom! So I thought I would post it, that’s all. It’s just a hobby to me! And it sure beats the hell out of doing nothing, at all! :wink:

Hey, the test was a heck of a lot better then anything else that has been posted so far and I don’t think djozz has one to test and I know I don’t so most likely the best results we will have for awhile.

Interestingly the results are virtually exactly what you would expect from 4x XP-L2’s put together from my own tests. They also peaked at 10A (which is what each die is getting in the XHP70.2 @ 20A).

I wasn’t saying that those tests should have been made with proper testing standards for everyone to see.
I was just wondering how long it was on when you took the measurement and what cooling you used so that I could guesstimate how well it would perform for me if I used a big heatsink.

Something to think about:
Every LED has a thermal resistance, the XHP-70.2 has an Rth of 0.9°C/W, so maybe 1°C/W to the solder joint. This means that for every Watt of heat converted power the LED is 1°C hotter compared to the solder joint. In addition to this you have the heat path to the outside of the flashlight.

At 20A and maybe a Vf of 7.5V (I’m guessing here) the LED gets 150W! EDIT: of which around ~80% is converted to heat (see posts below).
So the LED will be 120°C hotter than the the solder joint on the PCB is.
So if your lights are too hot to hold (pain threshold is at 60°C), the LED is at least 170°C hot.

At this temperature, which is outside the range of the datasheet, the LED loses around 25% of it’s output. Basically a big part of it’s high efficiency is wasted at this point.

The relevant power when considering the thermal resistance is the thermal power. Some of the input power leaves as light and so doesn’t contribute to the heating of the die. So only roughly 50-80% of the input power heats the die.

Right, forgot about that.

At these power levels it might be 20%.

So it’s “only” 120°C more.

I have corrected my post.

I think I have one on order from KD but it has not arrived. But I’m not sure anymore now, I have never made an account there so I can not see an order history, and KD does not send order confirmation emails with details of the items.

If it arrives after all I will do a test, but my power supply does not go over 20A and, as I read above in Kawiboy’s posts, that that is not enough, it is quite a performer!! :smiley:

If you have a 12V mcpcb then you can run it in 12V mode which would only need 10A to max it out.

Although while it may survive that high I can guess that running it above ~15A is going to be a matter of quickly diminishing returns to the point of silliness when you factor in the heat it will produce.

[quote=Texas_Ace]

The 15A buck driver you developed is starting to make a lot more sense now. :wink:

You flashlight mad scientist!

Meh, it came as expected . there was so many naysayers saying it wont happen but knowing Cree , getting Xhp70.2 was only a matter of time and cost.

Now i plan to pop one into a Boss with 4x26650 16v DD on a beefy 50mm thick chunky heatsink to get a whopping ~10k lumens single emitter compact thrower worthy of a flasholic envy. :+1:

This is what i call ‘Pushing on the limits of existing technology’. Doing anything less would be better off going the way of buying a production light.Why bother……