High Current (1A+) XR-E builds?

Curious... DIY noob gust getting my feet wet.

What success / failures have you all had running XR-E emitters at high current?... 1-1.4 Amps?

Please feel free to elaborate and include build up and failure pics... anything GOES!! I am trying to scope out my own projects and get a better feel for what works and what does not.:thinking: I have already experienced enough failures(LOL) to know theres more to this science than just blasting the LED with a bunch of 7135 chips... (noob mistake... MOre power.. .MORE JUICE... hahahaha... PFFFFT!:candle

thanks in advance!!

no problems with a XR-E on a star board at 1,4A so far.

Data has mentioned running an XR-E at 2A in his newest Spy flashlight, albeit for only about a minute before cutting back on the current.

i'm running a q5wc at 1.5-1.6 amps with no issues behind a dereelight smooth reflector. DD off an 18650, 1 C mag. d2dim is going in tomorrow.

i know this isnt a cree, but Photonfanatic's K2's rock.
i'm running the TVOD 200 TFFC at 2.2+ amps in a peak night patrol

Garrett,

If you recall my Nailbender 1D Mag XR-E LEDw/1.4A driver did only 170 out the front, but was around 140ish after 3 minutes as tested by MrGman.

Then I had Nailbender put a 1A driver and the lumens went up to 180 and after 3 minutes it stayed at 180 Lumens.:twothumbs

Granted; on paper I am 50~70 lumens short, but it is what it is. FYI: I used an IMR 18650 and KD "D" li-on and the results were the same.

More current should have given me more lumens;espeically in the Maglight with a dedicated heatsink. Hope this helps others choose their current wisely.

See this post for some discussion of thermal management.

In addition, the temp you might measure on a heat sink or flashlight body is not the junction temperature (Tj). Tj is going to be higher. If your MCPCB is at temperature T, your junction temperature can easily be 10C higher. The Cree docs contain a graph of relative luminous flux vs junction temperature. Output drops as the junction heats up. At Tj=100C, you can lose 20%. IMO, unless you have a good heat sinking solution, overdriving is a waste of time. You aren't going to get greater output. You will get shorter LED lifetime and shorter run time. It's not just some simple extrapolation of the Cree relative luminous flux vs forward current graph, where 1.4A forward current should give you 300+ lumens.

Unless you actually measure lumens for 1A forward current vs overdriving at say 1.4A forward current, the fact that the eye is a poor light meter works both ways. You also are not going to be aware of any drop in lumens due to excessive junction temp, even if it is there. You might even believe you are getting more output. And you very well might, for very short bursts only such that the LED doesn't heat up. If that is how you will use the light, then overdriving might be for you.

no problem here either, running 5xCree Q2 at 1.2A using Maxflex. I wish maxflex can reach 1.4-1.6A.

I run 4 Q5's at 1.4a in a water cooled mag.
Even with out water cooling it works with no issues.

Packhorse said:

I run 4 Q5's at 1.4a in a water cooled mag.
Even with out water cooling it works with no issues.

Click to expand...

Packhorse,

Krammer5150 is my co-worker and he voluntered to help put one of those 1.4A drivers from DX on the Q5 IST light you made for me. Do you think this would work out or will the Q5 turn blue

Thanks,
Jose

I make my own led lights..simple ones...and have run several at 1 amp and 1 and 1.4 amps. To be truthful, there wasn't a big difference. It's there, and I can see it, but for the added heatsinking needed, I'm happy with the power I get at 1 amp, and I'm using mostly p4 leds.

bigchelis said:

Packhorse,

Krammer5150 is my co-worker and he voluntered to help put one of those 1.4A drivers from DX on the Q5 IST light you made for me. Do you think this would work out or will the Q5 turn blue

Thanks,
Jose

Click to expand...

Actually, I think we are safer running it at 1A. by de-populating one of the 7135 drivers.

The bigger potential problem I can predict is... us messing around with someone elses design (and a $$$$ one at that). That kind of makes me uneasy.

bigchelis said:

Packhorse,

Krammer5150 is my co-worker and he voluntered to help put one of those 1.4A drivers from DX on the Q5 IST light you made for me. Do you think this would work out or will the Q5 turn blue

Thanks,
Jose

Click to expand...

I wouldnt guarantee it.
But in saying that I have done it my self and it didnt turn blue.
Problem was it didnt run at 1400ma for long. Maybe 20- 30 minutes then the voltage dropped and so did the current drawn by the LED.
The IST has a ship load of aluminium to help with sinking and it is supposed to be use under water which helps even more.