how to buy LED to get the right bin without being fooled

H.G.Sun · April 30, 2014, 4:52am

bought some poor xml2 LED. seller claim u2, which not brigher than xml t6 on hand.
I can tell xml2 from xml, but not bin, how to avoid this when buy. thanks for any comments

WarHawk-AVG · April 30, 2014, 5:33am

A. Buy from reputable vendors
B. Buy from vendors with good customer service and return policies
C. Buy using paypal so if they screw you…you can have paypal fight for you in a claim

Dimbo_The_Blinky · April 30, 2014, 5:52am

and
D. Report your experience(s) here, honestly and accurately, to “pay it forward”.

(“reputable” largely means what you can learn from reviews posted here and elsewhere on the Internet — after you get some experience you can afford to take more risks with strangers)

baterija · April 30, 2014, 6:22am

Warhawk’s first point is the most important. They are the same LED made in the same production process and then tested to determine bin. Barring Cree (or other manufacturers) marking the package after labeling there’s no way to tell directly just by inspecting it short of hooking it up in a controlled environment and measuring the output. There’s no telling what you are getting from a budget dealer.

That said you U2 binned XM-L2 might actually have been a U2. The difference from the midpoints of the bins is already well inside the ability for the eye to differentiate. The individual difference could be even less between samples. A U2 barely across the line into the bin could be only a fraction of a percent brighter than a T6 just under the line separating the bins. There’s also the issue of differing Vf which Cree doesn’t bin for. If your driver supplied current is sensitive to the Vf of the LED being driven swapping LEDs potentially makes big difference in drive current. The output difference from the Vf change is potentially bigger than the output bin difference. You could realistically have a U2 dimmer than a T6 with a lower Vf once you “upgrade” a light.

I generally go with the rule that one flux bin difference isn’t worth an upgrade unless there’s some other reason.

H.G.Sun · April 30, 2014, 6:51am

baterija:

Warhawk’s first point is the most important. They are the same LED made in the same production process and then tested to determine bin. Barring Cree (or other manufacturers) marking the package after labeling there’s no way to tell directly just by inspecting it short of hooking it up in a controlled environment and measuring the output. There’s no telling what you are getting from a budget dealer.

That said you U2 binned XM-L2 might actually have been a U2. The difference from the midpoints of the bins is already well inside the ability for the eye to differentiate. The individual difference could be even less between samples. A U2 barely across the line into the bin could be only a fraction of a percent brighter than a T6 just under the line separating the bins. There’s also the issue of differing Vf which Cree doesn’t bin for. If your driver supplied current is sensitive to the Vf of the LED being driven swapping LEDs potentially makes big difference in drive current. The output difference from the Vf change is potentially bigger than the output bin difference. You could realistically have a U2 dimmer than a T6 with a lower Vf once you “upgrade” a light.

I generally go with the rule that one flux bin difference isn’t worth an upgrade unless there’s some other reason.

that’s very through, you guys’re so cool.
Are you saying, cree make a bunch of LED first, then test them to categorize into bins? “They are the same LED made in the same production process and then tested to determine bin. ”

WarHawk-AVG · April 30, 2014, 7:07am

H.G.Sun:

baterija:

Warhawk’s first point is the most important. They are the same LED made in the same production process and then tested to determine bin. Barring Cree (or other manufacturers) marking the package after labeling there’s no way to tell directly just by inspecting it short of hooking it up in a controlled environment and measuring the output. There’s no telling what you are getting from a budget dealer.

That said you U2 binned XM-L2 might actually have been a U2. The difference from the midpoints of the bins is already well inside the ability for the eye to differentiate. The individual difference could be even less between samples. A U2 barely across the line into the bin could be only a fraction of a percent brighter than a T6 just under the line separating the bins. There’s also the issue of differing Vf which Cree doesn’t bin for. If your driver supplied current is sensitive to the Vf of the LED being driven swapping LEDs potentially makes big difference in drive current. The output difference from the Vf change is potentially bigger than the output bin difference. You could realistically have a U2 dimmer than a T6 with a lower Vf once you “upgrade” a light.

I generally go with the rule that one flux bin difference isn’t worth an upgrade unless there’s some other reason.

that’s very through, you guys’re so cool.
Are you saying, cree make a bunch of LED first, then test them to categorize into bins? “They are the same LED made in the same production process and then tested to determine bin. ”

for the most part

Kinda how they make processors…they make a ton of em on a die…test em…those that don’t pass this test fall into a different rating, and so on and so forth till they completely fail…each step down they get cheaper, scrupulous sellers will buy them then say they are something better to sell em…if they don’t have good customer service…the person buying the stuff they sold are stuck with em

Here is some great info on the emitters and whatnot

This too
http://flashlightwiki.com/Cree

And this
This as well

H.G.Sun · April 30, 2014, 7:31am

cool thanks,

Cereal_killer · April 30, 2014, 4:47pm

Since no one’s actually recommended any good/trustworthy sellers yet (and considering your listed location) I would recommend Intl-outdoors, other than a few US based sellers that I don’t believe will ship overseas (or will charge bokoo $$$ to do so) IO is the only Asian retailer I will buy emitters from.

Just recently I got a package of L2’s miss marked as T6 1D (orders U2 1D) and after speaking with Hank I’m confident they’re infact U2’s and even closed my PayPal claim, that’s how much I trust them.