testing a red XP-E, and comparing it to a red XR-C, 22/4/'14: XP-E2 results added in post #32

I ordered a Philips Rebel ES 660nm Deep Red LED, as discussed in another thread. Probably not as bright but redder.

Rmm at 1.9a would the red xpe2 make a Roche f12 get hot on high quickly? Or a tank007 e09?

I did the red XP-E2 (630nm) test (with big thanks to MRsDNF who sent me a few leds for free, coming from Cutter), above stereo-picture is after the testing. I also re-tested the red XP-E because it was sitting there reflowed on the Noctigon already, and I wanted to re-check everything, now that I use a new power supply. Below are the results. BTW: the XP-E results match reasonably the former results of that same led in the OP, so my two (both lineair) power supplies more or less agree on their current measurement (jay!).

So, another improvement over the the XP-E, although the Vf of the XP-E2 seems to have raised, compared to the XP-E.

But, although I think what I see is mostly the real difference between XP-E and XP-E2, also keep in mind that the XP-E was an unknown bin bought from Fasttech, and the XP-E2 was the top P3 bin bought from Cutter. (EDIT: the Cree tool mentions there is a P4 bin, but Cutter's bin is P3)

Wow, that’s an impressive difference, even considering that it’s an unknown bin XP-E vs top bin XP-E2. It is fortunate that it started with such a low Vf. I can’t see the higher Vf being an issue for running a single emitter on a single li-ion.

Great work!

Your results match what I've seen and what my customers have reported; a very significant increase for sure. More than what I think we've seen going from XP-G to XP-G2 and XM-L to XM-L2.

May I ask why you test voltage, current and lumens? :slight_smile:
I think http://pct.cree.com/ can give you this data from all Cree LEDs.
So am I the only one who knows this or did I ignore something?

I also did a test on a blue XP-E2 (also from Cutter), but no comparison to a blue XP-E. In short: 390 lumen at 2A, maximum=440 lumen at 3A (the absolute lumen numbers are not worth much when measured with a cheap chinese lux-meter that is especially off in the shorter wavelengths of the visible spectrum). I will post a graph later some time (if there is interest in that at all?). I have no green XP-E2, so no test on those I'm afraid.

I have not followed your link now (sorry, internet here is slow at the moment), but the last time I checked Cree's numbers, they had not measured the leds on copper boards, and gave no numbers on the higher currents we like to run the leds at.

Sometimes leds perform better than the manufacturers let us know :-)

EDIT: I had time to look into the Cree tool just now, and they indeed only give numbers for the red XP-E2 up to 700mA. Looking at the tool, a bit odd is that the Vf that they give is a bit higher than what I measured over the led wires (at 500mA it is 0.17V higher). My current setting in these measurements is not more precise than 100mA but still then the numbers that I measure are low compared to the tool (I checked, I did nothing wrong here, my voltmeter is correct within 10 mV, and any set-up inaccuracy would only make the voltage higher, not lower).

nice, thanks for the results ,now we need to find a place to buy those red xpe2.

thank you thank you for these tests! do put the blue one in a thread whereever you see fit =) very very helpful

I will do a blue post ;-)

And the test XP-E2 is in my favorite AA-zoomie for the time being, drawing 1.5A from the stock driver with an Efest 14500 battery :-) :

nice, a red zoomie, you can become the new cat emperor 0:)
settling with my focus adjustable red laser pointer until i can get around to some new builds for now :wink:

Wow, I’ve been looking for how to make an amber zoomie, just like your red one.
Amber ought to work the same as the red — if an amber is available anywhere.
Oh, please …. pointers welcome any time.

I have this one : Luxeon REBEL yellow on PCB - LXML-PL01-0030 on aluminium PCB

NOT powerful, but really nice tint.

Djozz, I love that AA-zoomie you show above. What’s the host and where did you get it?
(I can find what looks like that several places but nowhere that describes what’s inside)
I’d like to put an amber into a host using the stock driver (figured I’d blow up the LED if I tried that with most lights)

http://www.tinydeal.com/focus-highlight-180-lumens-3-modes-cree-r2-flashlight-with-strap-p-100672.html

It is optically identical to a lot of 18650 zoomies, but with AA-size battery. The lens is a larger diameter than the sk68, so it throws a bit better, and IMO it is better looking too. The build quality is very decent.

(are you overdriving that red XP-E2 at 1.5A, or is the driver protecting the LED? getting hot? don’t know what driver is in it, obviously, I’ll get one and try)

The driver in this flashlight is a standard budget AA boost driver that goes sort of direct drive on 14500 li-ions. On li-ions the current is limited by resistances in the system, including on the driver board. 1.5A is ok for the XP-E2, as you can see in the graph above, I would like the led to be driven at 2A so I may swap the driver sometime, or put the led in another host (I have a C8 host doing nothing yet...)

Maybe the Osram Oslon SSL 80? I found them here: OSRAM Oslon SSL 80 amber on Star - Oslon SSL 80 LACP7P-KPKR (KR)

> Osram

mA typ.: 350 mA
mA max.: 1000 mA
V typ.: 2 V
V max.: 2.6 V
Watt: 0,7 W

That’s a higher maximum than the Cree — searching for that available near me.

While searching, that led me to a wonderful collection of LED spectra:
http://www.1023world.net/diy/spectra/

that may be useful for comparisons (much in Japanese I can’t read