XHP35

Flashlight Modding and DIY Parts
82

I am hoping to get some numbers before long, KB was nice enough to offer up some sacrificial LED’s to be killed tested.

I got some early numbers from a low bin C4 90+ CRI HD and they were pretty good, it handled 3A for quite awhile without an issue and even handled PWM from a full 16.8V. I think these are tougher then we have given them credit in the past.

That said from the early test output seems to peak at ~2.8A with very little gained over 2.5-2.7A but I will wait till I have the nicer bins to make any conclusions.

83

Yeah, I think I recall reading here somewhere that going over 2.8A doesn’t give much… But still, interested to see any test results where some actually end up frying :smiling_imp:

84

Anyone know the actual light output of one of these at 2.5A? Any bin, it’s just to get an idea

85

The HI and HD appear to give a significant difference in output. The output appears to range from the low 2000’s for the HI to high 2000’s for the HD.

86

Thanks for that TA!

87

Is that OTF in a flashlight?

The XHP35 HI E2 3C I measured output about 2600 lumens at 2.5A.

88

Ok. Thanks.

89

No, that is a low C4 bin 90+ CRI “raw” in my sphere.

Which is why I am waiting to get the LED’s from KB and run more tests before posting the results.

90

Is it too good to be true Mountain Electronics list a XHP35 HI with E4 flux bin

http://www.mtnelectronics.com/index.php?route=product/product&path=60_114&product_id=763

91

Nope, I have a few of them from cutter. I am guessing he got them from the same place.

92

Also remember to let the LED warm up a little before going full power.
I recently killed an XP-G2 by cold starting it immediately to 6A and the tiny gold wire blew.
With my other XP-G2 I left it on medium for quite a few seconds before switching it to 6A and it survived :slight_smile:

93

I have noticed this as well. In the sweep test it will be on for a long time as I build up to max power. Although once lumens start dropping I will most likely turn it off, let it cool down and start the test from that point again to see what happens.

94

They’re going fast too. Just a week ago or something there was about 135 of them in stock… It’s down to 5 now.

95

Yeah I got 2 a few weeks back, now there is only 3 left from this second batch? It’s probably Vinh! :smiley:

96

When I did this test a few days ago, I basically had my emitters floating in mid air so I only let them have power for a second to get the reading then quickly shut them off. Even in that 1-3seconds, I got a little smoke. I figured it was due to the non-existent heatsinking. I now have the 4 of them in a TM16 head and I’m testing again. I’m up to 240pwm level = no smoke, but as soon as I give them direct drive, I see the smoke. This is still while drawing around 8.5amps according to my clamp meter. Under inspection, the emitters look immaculate. I’m not sure where the smoke is coming form.

Wait a sec… just got a “low battery” on the meter… brb —— New batteries=same results

97

Forget it. Testing is over for a few weeks.

I just lost an emitter to a centering ring who wouldn’t sit still. :rage:

98

Interesting. What bin XHP35 are you using? Based on my measurements of the forward voltage of the XHP35 HI E2 3C, I estimate more like 12.5A in total flowing to the 4 emitters direct drive. Maybe your emitters have a higher forward voltage or there is more resistance in your circuit than in my calculation.

99

I was using these -> http://www.kaidomain.com/p/S026091.Cree-XHP35-HI-D4-50E-Neutral-White-5000K-LED-Emitter

I didn’t charge my batteries since the first test, so they were probably around 4.1v I would assume.

100

If you put them in parallel without balancing resistors you could get one with a relatively low forward voltage, resulting higher current to that emitter

101

True. I hadn’t thought of that.