LED emitter confusion!! Why the low rating?

I am one Digikey looking to buy 6 new emitters for my SRK and thought the XP-L emitters where Hi lumen output. In the top part of the chart it says. FLUX@ 85 degree C, current-test. 450 lm (440lm-460lm) Does this mean these emitters will only put out 450 lumens? I am very new to the game but love learning. I will be using a SRK V2 FET + 7135 Driver and want 6 emitters that will handle it. I am a very hands on type of person and need to know the whys even though I can do or fix something, analytical brain I guess. Thank you, Any help would be highly appreciated :slight_smile: Texas Ace, I you read this i’ll take the FET driver. I’ll PM you later.


That’s not on max. rated current.
I don’t know, looks like 1.25 Ampere.

It’s very Greek to me and I would like to understand how to read it :smiley:

Take a look at the XP-L data sheet. XP-L bin ratings are stated at 1050 mA (~1 amp). We typically run then at 3x or more than that.


Also, take that”manufacturer part number” and look it up in the data sheet. It’ll tell you exactly what it is.

The XPL v5 bin has an output of 460 lumens with the led junction temp of 85c.

At 25c juction temp its output is 513 lumens.

This is at a drive current of 1050ma.

The XPL can achieve over 1100 lumens at 3 amps of current [cree rec max] or if over driven on a copper direct thermal path star up to 1800-1900 lumens.

There is also a new gen XPL2 which is brighter again.

The XP-L2 can take even more amps than the XP-L, but I’d say they’re not for everyone. Like the XP-G3, quite a few of them have bad tint shift (hotspot has a different tint than the spill). I put 4 in an Astrolux S41S (quad) and it took some getting used to. If you’re expecting it and you don’t plan on doing much white wall hunting, they’ll be just fine for everyday / outside use. I got mine from Arrow for like $3.50 each, free shipping.

Read the other columns, they tell you what voltage and current they are tested at.
Obviously an LED will make less lumens at 1.5 amps than at 3 amps.

OK, This helps me a lot. Thank you. So at 1.05A at 185 degrees it will put out 460 lumens. So driving the emitter with proper thermal cooling an 3A will produce a much higher output. :smiley: 6 emitters should do nicely then lol :smiley:

Yeah, approx 3x more if you cool it well.
You can take a look at graphs on google of tests done at much higher currents, just search for “XP-L HI graph”

Sweet, thanks :smiley: This is going to be fun. My 3/8’’ copper plat should be here at the end of the week.

Bookmark Djozz’ tests. The op links current/Vf/output for most of the emitters we use when mounted on a closer to ideal heat sink. Where you might choose to operate on the curve should depend on how your heat sinking compares to his.

Look Here for manufacturer ratings at higher currents. Select v coarse in the pulldown menu at the top for current range.

Wow! The chart gives you multiple emitter parameters as well. Thank you Cbrake10!!! :slight_smile: