Recent LED Strip Comparisons?

[stevemayman]

Agree. Probably producing low quality and claiming the specs of what they are imitating...

There's also the possibility that the strip manufacturers are simply regurgitating the spec sheets from the LED supplier, which may simply be doing a back-of-the-napkin calculation based on spec sheets from their LED die and phosphor manufacturers.

Fair point. I should have included more info on what I was comparing! Although I looked at all densities I was only comparing the densest single-wide loading for each package. That was 120 diodes/meter for 3528s, 60 diodes/meter for 5050s, 204(!) diodes/meter for 3014s etc.

My only quibble with your table were with your "Max Lum/FT", "$/5M", "LED/5M", and "Lum-ft/$" calculations, as those are not specific to the diode type with 1x, 2x, 3x, and 4x densities available in many of those LED types (especially 3528's). If you're comparing whatever passes for "standard density", then my quibble pretty much vanishes.

 

[bshanahan14rulz]

Those burned LEDs, could it be to run them in clean air for a while to clear them up?

 

[SemiMan]

Those look like the "water proof" kind covered with a silicon type product, the ones I have been messing around with are open to air flow. I wonder if the silicon is trapping the heat more than the non water proof kind?

Almost definitely, but then it is a matter of picking your failure point. Silicon protects the LEDs and board.

Semiman

 

[SemiMan]

Your analysis looks very good for the samples you include. Unfortunately, the conclusions that can be drawn from it cannot be extrapolated to other strips using the same LED packages. It's possible to either put an efficient, inexpensive die in a 3528 package, and pack them tightly on the strip, or to put an inefficient, expensive die in the same package and space them widely on a strip. The results would be radically different, even though the package is the same. In other words, 'quality' cannot be determined by looking at the LED package type.

Lumen maintenance, the opposite of the 'burn-out' described by alpg88, is definitely affected by temperature. But keeping the LEDs cool does NOT ensure good lumen maintenance. It only ensures it will be better than if the LEDs are allowed to run hot. I have a nite-lite that has a few 5mm white leds in it. They certainly run cool, but after a year (8760 hours) running almost 24/7, it was notably less bright, which means probably 50% maintenance. Good LEDs like Cree or Philips have 70% maintenance after 50,000 to 100,000 hours. Now, after 6 years (around 50,000 hours), it barely puts out any light at all. You can see the light, but it doesn't illuminate anything more the a foot or two away. That's probably less than 5% of the original output, or 5% lumen maintenance at 50,000 hours, where a good LED would be 70% at 50,000 hours.

That is epoxy/phosphor interface yellowing and a known issue with most 5mm white LEDs.

Semiman

 

[stevemayman]

I wonder if that is something that industry-leading manufacturers would have solved by now? Perhaps the expensive diodes would no longer have this problem?

That is epoxy/phosphor interface yellowing and a known issue with most 5mm white LEDs.

Semiman

 

[SemiMan]

I wonder if that is something that industry-leading manufacturers would have solved by now? Perhaps the expensive diodes would no longer have this problem?

Most long life LEDs are silicone encapsulated not epoxy. Some 5mm will do long life with special construction.

Semiman

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[lovemyleds]

I can tell you from my own experience... I'm very happy with my 5m 5050 led strips. On my 5th reel of 5m. I buy nothing but 60 leds to the metre. I don't think you can get more leds to a metre than that. As far as colour goes... I do think around copper white is the brightest, though considering leds are sharper on the eye, I make an effort to reduce this buy getting warm white. It's not as bright, but not as sharp and gives off plenty of light. I don't pay more than 17$ AUS per 5m reel. Haven't had a single led go on me yet! And I don't even have them running through a 12v regulator. Good luck!

 

[SemiMan]

How many 10's of thousands of hours have you been running them?

Semiman

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[alpg88]

you don't need thousands of hours, in 2 months of none stop use at 12v even glued to aluminum profile, will dim the leds to 1\4 of initial brightness, i have seen it happened many times, never seen it not to happen actually.

 

[bshanahan14rulz]

Do both encapsulated and non-encapsulated LED strips dim to 1/4 brightness in 2 months, or do the non-encapsulated ones last longer? Could it simply be the encapsulant is just discoloring due to contamination and heat? Or perhaps the encapsulant isn't compatible with the actual LEDs' silicon fill?

 

[alpg88]

i used only waterproof ones.

 

[SemiMan]

Take your pick. Poor led quality, incompatible or yellowing encapsulation, overdriven LEDs ... All can contribute.

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[bshanahan14rulz]

Alright, so the bottom line is that there is no such thing as a well-made LED strip.

Anybody ever found some blank LED strips? i.e. unpopulated ones that we could put our own LEDs on?

 

[SemiMan]

No there of course are good ones, picking them is hard.

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[alpg88]

there are good led strips, but they are not flexible, and cost a lot more. i never personally used them, but they look like they have everything other strips miss, like good heatsinking, and good leds (rebel or cree) leds, and abuility to use optics. google 9008 LuxStrip II™

 

[WeLight]

one observation, you have your CRI numbers back to front, cool is more likely 65-70cri and warm is typically higher

 

[LEDealer]

one observation, you have your CRI numbers back to front, cool is more likely 65-70cri and warm is typically higher

+1

In general, you can find the highest CRI parts from most manufacturers in the 2700-3000K range (90 and above), 80 CRI usually is available up to 4500-5000K, and 70 CRI is between 2700-6500K and above. For these cheap LEDs on strips, I'm pretty sure that they're below 60 CRI if nothing is indicated. Midpower products are definitely available with high CRI for a dime for larger manufacturers, so it is a design choice by these strip manufacturers to not go with better LEDs. I think what you'll see is big boys like Cree, Nichia, LumiLEDs, and Osram coming out with their own "premium" strips so they can capture some of the value of putting LEDs on a strip, which seems like a fairly simple thing to do (once the design is nailed down).

In addition, the CRI tends to go up with temperature, so if a product is measured at 25C and is a 70 CRI minimum, it could be a 72 CRI minimum product at 85C or 100C...

 

[idleprocess]

I think a lot of this is due to the niche/hobbyist nature of the product with its associated low volumes. The lighting industry would likely categorize these as "under-cabinet lighting" - a pretty narrow segment of the market. Whenever some enterprising soul packages up and adds connectors to these things, the price multiplies several times.

There seem to be 2 pricing tiers for flexible low-power tape: dirt-cheap and scalper, without a meaningful performance distinction between either. There seem to be no name brand tapes, and - unless you pay the scalper price - they are not sold by anything resembling a name-brand distributor. Most sites site that sell them remind me of an ebay store - hype layered upon hype with confusing layouts, inconsistent parameters, specifications that don't always add up, and otherwise only inspire me to pay as little as possible and watch my six afterwards - even the local place!

Conversely, the mid- and high-power rigid strips seem to typically be priced quite high, although they at least offer more meaningful performance differences.

 

[LEDealer]

There seem to be no name brand tapes, and - unless you pay the scalper price - they are not sold by anything resembling a name-brand distributor.

I think the market is moving in this direction and you will indeed see name brand tapes soon. Why wouldn't these big names in LEDs want a piece of that pie that they can bake from all of the low hanging fruit out there?

 

[idleprocess]

I think the market is moving in this direction and you will indeed see name brand tapes soon. Why wouldn't these big names in LEDs want a piece of that pie that they can bake from all of the low hanging fruit out there?

Is there sufficient volume to make it worth their while?

Can they make a profit making it for a price that people will pay? Or will fleabay and amazon continue to encourage pricing too low for anyone but the cheapest producers to make narrow margins?