LED Lightbars

Ok guys, I know most of you know your LED lights. OK here is the question.. I know you can slap a well known LED in a light and put a price on it. Like Ridgid Industries and Vision X. But what about CREE Ebay Light Bars? I know its not all in the LED what makes up a light. You got Divers, Heat Sinks, Soldering, and other Electronics.. What makes up a good quality light. So my question is. Why pay 500$+ on name brand and spend under 300$ for a ebay cree LED light bar.

https://www.facebook.com/photo.php?...10.1073741826.1429380977291190&type=1&theater

Well I run rigid D2's on my VStrom (adventure bike). I drop it, beat it up and lots of other things I shouldn't do. Watch rigids sales video... That is what sold it for me. I have to have something dependable, and failure may leave me in the woods on trail somewhere in the middle of the night.

Sent by my NSA monitored Verizon Galaxy Nexus.

I've noticed some of the cheaper bars aren't supposed to be run without airflow. So if your crawling or on a slow trail they aren't a good option.

Something else I like about the higher end bars is that some of them offer 5000k color temp instead of 6500-7000K. Also there are more options for replacing the optics and I haven't seen cheaper bars that offer that.

Heat sinking. Optics, how well they shape the beam and how some have spot and flood combos. Quality of the wiring. Cast versus machined aluminum. Rigid comes with a complete wiring harness and good switch. Lens quality and how it's held in place. Some of the cheaper ones seem to be using RTV or Superglue even. The mounting hardware. A lot of the little stuff that adds up.

I'm guessing the Chi-Com stuff doesn't do a lot with the reflectors and optics; RI as an example, you can go in their catalog and see lighting profiles so you know exactly how the light is distributed. Not only that, but they have side view profiles; this really tells a lot... Some of their lights are just simple flood and spot, but some of them are designed with oblong beams so light isn't wasted to the immediate front foreground and up where the birds are sleeping.

Oh and did anyone mention quality? lol

Have you considered the lef tape? I used it under my cabinets and it is very thin and very bright. I put them on a dimmer and everything cost under $200.

I have disassembled Aurora which is a "knock-off" of Ridgids products. They look pretty good inside and have a decent price point. They also come in two varieties as one infringes on Ridgids patent.

There is also Hanma which wasn't as good but still did the job.

Moved this to Automotive Lighting, Motorcycles Included forum.

Bill

riss6270 said:

Have you considered the lef tape? I used it under my cabinets and it is very thin and very bright. I put them on a dimmer and everything cost under $200.

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I don't think he read anything?

I just wish there was a warm white version of these lights. Everyone is going to the 6000K LEDs, which aren't the best for night driving.

dajeepman said:

what about CREE Ebay Light Bars?

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You can find hundreds of different lighting products for car, home and office on eBay (and elsewhere on the net...alibaba, for example) sold under the CREE name. Cree doesn't make them. Cree very likely doesn't make the LEDs in them. Virtually all of it is counterfeiting and theft of intellectual property (Cree name and trademarks). The use of the Cree name is intended to get people to think "Oh, hey, Cree! That's a good name in LEDs!" and buy.

-Virgil- said:

You can find hundreds of different lighting products for car, home and office on eBay (and elsewhere on the net...alibaba, for example) sold under the CREE name. Cree doesn't make them. Cree very likely doesn't make the LEDs in them. Virtually all of it is counterfeiting and theft of intellectual property (Cree name and trademarks). The use of the Cree name is intended to get people to think "Oh, hey, Cree! That's a good name in LEDs!" and buy.

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I've had the pleasure of disassembling some of these devices and found that the ones I've purchased did in fact use real Cree emitters as advertised but they were under driven so much that the light output was no where near the potential it should have been. I've had the same experience with Osram and Epistar based products too. Even in lamps which seem to have adequate heat sinking with large fins, metal PCB's attached to the housings with ample thermal compounds, the LED's are driven at 1/2 to 1/4 their potential outputs. I'm not sure if they're doing this because of poor quality drivers unable to handle higher currents, poor PCB traces unable to handle higher currents, or just for sake of lower failure rate with what could be 2nd or 3rd quality emitters. I have noticed with Cree XM-L and XM-L2 based products color binning is poor, often two or more LED's will be of slightly different color, but equal intensity. At distance the color variations are mixed by the optics so it's not really a problem for something simple like a bicycle light or a cheap 'throw away' flash light. I just can't get over how under driven the LED's are! There has to be a reason, but I haven't figured it out yet for sure beyond my speculation of poor quality 2nd and 3rd rate parts, not every Cree or Osram emitter is going to run at full power with full lumens, much like not every Intel or AMD processor will run at the full speed the design is capable of. I'm not qualified to make the call on why they under drive so badly though, and we know the vendors on eBay don't know either. My Chinese is too poor to ask the factories directly so that's out, all I can do is speculate.

My rule of thumb for most Chinese LED products is expect 1/2 to 1/4 the advertised results. If it says 30W it's likely more like 10W, if it says 3000 lumen it's likely closer to 1200 lumen, based purely on my own experiences.

Except Epistar does not make LEDs ... only LED Die.

Bitter said:

I've had the pleasure of disassembling some of these devices and found that the ones I've purchased did in fact use real Cree emitters

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Real Cree...rejects?
Real Cree...lookalikes/counterfeits?
Real Cree...name inkstamped on who-knows-what generic junk?

All of those are believable.

-Virgil- said:

Real Cree...rejects?
Real Cree...lookalikes/counterfeits?
Real Cree...name inkstamped on who-knows-what generic junk?

All of those are believable.

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They match visually what a XM-L2 should look like from the Cree data sheets exactly. It is possible they are counterfeit but usually those show some discrepancy like lines across the LED where there should be none, wrong color of the base, wires on the wrong side, dot in the wrong location. It also appears the same as other XM-L2 emitters which I believe to be genuine. Possible these are fakes but I doubt it, unqualified I may be to make that judgment.


I assume I can hotlink from my own photobucket account, so here are some photos of what I took apart and the woeful amperage they draw to illustrate how underdriven the ebay products often are.





Close up of the emitter


This was an advertised 20W light, my intended use was for a golf cart to replace the 35W halogen trapezoid sealed beam with something that would throw a little more light, the 35W halogen is quite dim. As you can see the whole thing is drawing just a hair over 10W. Light output wasn't terrible but not as bright as it should be. The housing barely broke 100F, so likely they were so under driven for heat reasons. The XM-L2's are capable of taking some heat but the other items on the board may not have been. I had thought about looking further into the circuit design to see if there was anything that could be done to boost output but some of the chips are illegible so I decided to leave that alone.

Bitter said:

They match visually what a XM-L2 should look like from the Cree data sheets exactly. It is possible they are counterfeit but usually those show some discrepancy like lines across the LED where there should be none, wrong color of the base, wires on the wrong side, dot in the wrong location. It also appears the same as other XM-L2 emitters which I believe to be genuine. Possible these are fakes but I doubt it, unqualified I may be to make that judgment.

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Good thing counterfeiters will never be able to access Cree datasheets. Because if they could, they'd probably never get the wrong color for the base or put the dot in the wrong location, or make other noob mistakes like putting the wires on the wrong side. Keeping datasheets out of their hands will ensure they'll just blindly guess at what a Cree emitter really looks like, and so counterfeits will be easy to spot.

Alaric Darconville said:

Good thing counterfeiters will never be able to access Cree datasheets. Because if they could, they'd probably never get the wrong color for the base or put the dot in the wrong location, or make other noob mistakes like putting the wires on the wrong side. Keeping datasheets out of their hands will ensure they'll just blindly guess at what a Cree emitter really looks like, and so counterfeits will be easy to spot.

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Thinly veiled sarcasm is thinly veiled XD

By the way, any way Bitter can get a clearer shot of the phosphor pattern? The XM-L2's have a checkerboard pattern which seems to slightly come through under the dome. That, and I see a bunch of random resistors and capacitors scattered around the board. would the affect amperage adversely in any way? - I see that you will be looking into it

what makes anyone think those leds are fake???? they look like real xml2 to me.

Sorry, that's the best photo I could get of it. My point and shoot only does that well and the D60 I have access to doesn't have a macro lens.

I don't discount the possibility of fake, I just doubt it in this case. Poorly binned and under driven, no doubt. As Virgil would say though "You're not qualified to make that determination" Now 'Chinese' batteries on the other hand....
http://forums.mtbr.com/lights-night...l2-3-mode-bike-light-944406.html#post11687386
I have some of these that came with my eBay throw away lights for work, I have no doubt they're filled with rice flour and bean paste.

alpg88 said:

what makes anyone think those leds are fake???? they look like real xml2 to me.

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Are you not aware of the enormous counterfeiting industry in China? It covers absolutely every product segment and every brand you can think of. There are entire towns doing nothing but counterfeiting. And every last little detail gets copied -- not just names, but also fonts and ink colors and packaging. Often it doesn't even have to be "copied" as such; when the factory is done producing the (say) 500,000-item order, they keep the lines running. The real customer gets their order...and items number 500,001 and subsequent get sold through "other channels". And you didn't think they throw away the seconds and thirds (rejects) that work, but aren't to spec, do you? No, those get sold through "other channels", too.

"What makes anyone think these [Cuisinart food processors, Sony TVs, Western Digital hard drives, fill in the blank] are fake???? They look real to me...just because in Chinatown they cost 1/3 what they cost everywhere else...that doesn't mean anything!".