How long do LED shop/ceiling lights really last at full output anyway?

How long do LED shop/ceiling lights really last at full output anyway?

In another thread, the topic came up that LED lights may not last as long nor as bright as claimed on the package:

Lights of America exaggerated LED light bulb performance

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Since the failure mechanism is electronic as much as it's the fact that LEDs diminish in light output over time, I wondered how long the LED lights (the entire unit, including electronics) really last, and, what "rules" were in place for the claims on the package (since I never get the life that the fluorescent or incandescent bulbs claim either).

As just one (admittedly egregious) example, the bulbs referenced above:

CLAIM: Replaces light output from a 40 Watt bulb (aka 400 lumens) TESTS: The F.T.C. found the bulbs produced only 74 lumens of light

CLAIM: The LED bulbs in question would last 30,000 hours TESTS: They lost 80 percent of their light output after only 1,000 hours

That didn't even cover sudden failure from the electronics.

So, I wonder aloud ... How long do LED shop/ceiling lights really last at full output anyway?

Reply to
Algeria Horan
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Doing some due diligence, I find that there *are* rules in place.

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The Lighting Facts label contains:

  1. a bulb?s brightness,
  2. energy cost,
  3. life,
  4. light appearance,
  5. and wattage

Specifically:

  1. The brightness in average *initial* lumens rounded to the nearest 5
  2. Life in years, rounded to 1/10th based on a low usage of only 3h/day
  3. Color in Kelvin ranging from 2,600K on the left to 6,600K on the right
  4. Wattage in average *initial* wattage

Note that, for LEDs, the "initial" specs are almost certainly going to be vastly different than the actual specs over time, so, already, the label has to be taken with a grain of salt.

where I live).

But at least we know what the LEDs are supposed to deliver, initially.

So now we need to figure out what typically happens to these LED light bulbs over time, mostly in terms of light output & when the lifetime brightness cutoff point has been reached.

Reply to
Algeria Horan

Put one in, and leave it on so it runs up the hours, and see when light diminishes.

Most of us haven't had LED bulbs long enough to have any feel for their lives.

I'd also point out that if you read the fine print on the LED bulb packages, the number of years they last is based on a limited number of hours every day. So they may try to make the figures look good, but the actual hours may be okay, if somewhat low. I leave the ceiling light on all day, that will diminish the numver of years the bulb lasts if I look at the stated "number of years".

On the other hand, prices are dropping, I just got a "100W" LED for 7.99 rather than the regular 19.99, and the lower wattage LED bulbs are already going to lower regular prices. And I'm using something like 19Watts (I think actually less) compared to the 100W of an incandescent bulb, so power usage is down.

Michael

Reply to
Michael Black

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Reply to
Scott Lurndal

That's effectively what most of you have done, since many of you have LED lights (I only have one, which I bought from Costco about two months ago, to replace a non-standard bulb ceiling fixture).

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I have the box in my hands. Here's what it says on the box:

Light Output: 1,495 lumens (remember, that's only the *initial* output!) Watts: 21Watts (remember, that's only the initial watts) Lumens per watt: 71.19 (why is this even there?) Color Accuracy: 82 CRI color rendering index (whatever that means) Light Color = 3000K "Bright White" (which isn't white on the scale)

They do reference more information: Web:

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Telephone: 800-787-1021x4

Going to that web site and typing in the model number of "AL-3151" was a wasted effort as they have just the label that is already on the package.

Calling that number was also a waste of time, because the customer support guy said "it lasts more than 5 years because that's the warranty if the driver fails", which is also a stupid answer (they can give me a warranty of

500 years and it still doesn't answer the question).

I pressed for a real answer, and the guy said "50,000 to 60,000 hours", to which I was incredulous. So I simply asked where he got that figure, and he said that's what he says for all questions.

Obviously he was blowing smoke at me, so I asked for someone who actually wasn't gonna just make this stuff up, so he transferred me to his "technical support" guy, whose email is apparently gmijangos at jimway.com so I left him a message to let me know what the *tested* lifetime of the lamp is.

Disgusted, I called the Costco Wholesale number on the package,

800-774-2678, x3, product information, x1 product information and they took down my information and said they'd get back to me on the L70 lifetime.

One thing the operator had handy, which is more smoke blown in our faces, but which she kindly stated it was all she had, which was "LED *chips* last

50,000 hours, 34 years@4 hours/day).

That's not what we're asking, since we know two things: a. The LED chip output diminishes from day 1 b. The driver is the weakest link with respect to lifetime

The problem with *everything* on the planet where there is a choice, is that the MARKETING people only talk about the good stuff (e.g., FWD slides straight in the snow, for a hilarious example), but they don't talk about the BAD STUFF (e.g., weight ratios and working in the engine bay are atrocious for most FWD cars).

So, the problem that I see with the LED marketing is that people are only talking about the good stuff, which is all fine and dandy.

But I'm looking for information on the bad stuff too.

Like the fact that the output decreases the moment you plug it in,

Apparently, it's based on 4 hours per day, based on what I wrote above.

I'm not sure why the total number of hours would be different if you use the light for 4 hours a day or for 24 hours a day, but apparently it is.

On the bulbs you just bought, what's the L70 time period?

Reply to
Algeria Horan

One of the failure mechanisms is insufficient heat sinking, so the electron ics (probably the electrolytics in the SMPS) get cooked and die earlier. C heap bulbs may be OK when mounted base down, but have reduced lifetimes in other orientations. The more expensive ones may have better heat sinking a nd better tolerate being mounted base up. Feel how hot the bulb gets at th e neck.

Reply to
jfeng

Thanks for that url. Here's a relevant set of snippets from:

Understanding the Cause of Fading in High-Brightness LEDs By Steven Keeping Contributed By Electronic Products, 2012-02-21

LED failure? is most likely to be the result of light output falling below an acceptable threshold (typically 70 percent of the initial output.

The primary cause of that fading (or ?lumen failure?) is triggered (for the most part) by the minute threading dislocations introduced to the chip during wafer manufacture.

Threading dislocations are a major problem...where threading dislocations are vertical micro-cracks caused by strain generated by the mismatch in InGaN and Sapphire or SiC crystal lattices .. and where ... things get worse over time, as the rate of degradation is directly related to the initial density of threading dislocations and the heat to which the LED is subjected ... all of which gets worse ... due to heating during operation, thermal expansion and shrinkage when the LED is turned on and off, and mechanical stress such as vibration.

Worse yet ... as the chip ages, it will run hotter and hotter ... due to an increased number of phonons, accelerating the formation of dislocations and the device?s eventual demise.

------------------- So now we know what kills LEDs to the 70% level (which is the formal definition of dead), which is that inherent cracks between crystals form over time, just as mud cracks as it dries at the bottom of a pond.

The fundamental problem is cracks between crystals only gets worse. b. Heat makes things worse even faster c. On/off cycles makes things worse even faster d. Vibration makes things worse even faster

So, given they don't heat/vibrate/cycle the LEDS (other than the 4 hours per day), you'll likely never get the advertised L70 lifetime in the real world.

But what do you get for a 70%-illumination lifetime in the real world?

Reply to
Algeria Horan

I forgot to mention that none of what kills the LED over time discusses the frail electronics, which also fail.

So, we need to know how long the "LED drivers" last too.

The life of the fixture is the shorter of the two failure modes: a. Inherent cracks between crystals get exponentially worse over time b. The drivers suddenly fail at any time

So, we still don't have any decent grasp on how long LED fixtures last, in the real world.

Reply to
Algeria Horan

High end LED devices (Cree/RAB/GE) will last many thousands of hours and i f they last the first 200 hours, will do so pretty much without further ado .

In a previous life, I managed retail shopping centers, wherein we replaced lot lighting with LED devices (RAB) in the 2700K spectrum. Where we were re placing lamps on-average once per year throughout the center, it has been t hree (3) years now without a single failure at one location, and two years without a single failure at another location. And this is 60 heads at one location and 22 at another.

As to residential LED lamps - if you buy crap, expect crap in return. As pr eviously noted, heat-sinking is critical, assembly quality is critical, and the actual LED emitters are critical. I have done two offices in CREE devi ces, with one (1) failure in three years. And that was within the first 200 hours - replaced by CREE including shipping both ways without a murmur.

They were not cheap, but, they worked and still are working. And the power savings are dead-on per the package statements.

Guys and gals, this is not rocket science. We were early adopters of the te chnology, true, and perhaps paid for that earliness in first-cost. But, eve n at that price, the paybacks have been as-represented. And I have learned over the years the perils of being price-driven for any new/cutting edge te chnology at all, and especially for one where the price disparities are sig nificant.

As far as "due diligence" is concerned, about any manufacturer can paper th eir way to an impressive review, and the FTC has this touching habit of bel ieving what they are told until beaten down with the clue-stick-otherwise. Ask a USER. Several users. And if a manufacturer/supplier cannot give you a s many users as you wish, RUN, don't walk away. Or, if the technology is so new as there are, legitimately, few users, ask about paying out of the pro mised savings. I have had excellent success on that basis. The REPUTABLE Ma nufacturer wins by gaining a sale, and a referral, you win by 'seeing' the savings right up front.

We are gradually shifting to CREE devices at home - as our 8+ year old CFL devices gradually die.

One last note: Habitat for Humanity was selling 19-watt LED Devices for $1 a few weeks ago, from China, of course. I invested $3 to check them out. O ne (1) device in our Kitchen lights stepped on every radio/tuner AM or FM i n the entire house (4,800 square feet, three stories) including brands and devices from Zenith (9S262) to Revox (A720). About the only things that did not seem to be affected were our WiFi router and cell phones. We have a do zen CREE lamps, and no issue from them.

Peter Wieck Melrose Park, PA

Reply to
pfjw

YIKES!

I built my own LED light replacement for 48" tubes in our kitchen. They have been running about 2 years, now. If they have lost some output, it is not real obvious to me.

I'm getting something like 2000 lumens from a 20-LED string, running on 21 W measured from the mains supply.

I can't reply to commercially produced retrofits, some of them are apparently quite awful.

Jon

Reply to
Jon Elson

Dunno. Your real world LED application is not the same as my real world LED application and the science fiction world of marketing tech products.

Perhaps you might be interested in "lumen depreciation", L90, L80, L70, TM-21, LM-80, LM-40, etc. There are some interesting methods of calculating LED life such as: "Reported TM-21 values have an upper limit of 6-times the number of LM-80 test hours. So if an LED chip is tested for 6,000 hours, its max reported TM-21 lifetime would be 36,000 hours. If the chip was tested for 10,000 hours, its max reported TM-21 would be 60,000 hours." Magic is a reallly nice way to produce bigger numbers.

One can also be devious:

TM-21 ratings, "reported" and "calculated" ratings." Sigh...

Few run 30,000 hr tests. At 8,760 hrs/year, it would take over three years to run the test, by which time the product is obsolete and replaced by something new and improved. Instead, they run a HALT (Highly Accelerated Life Test), which is faster, and presumably produces the necessary inflated figures: The basic idea is to test the LED at various elevated temperatures, connect the dots on a graph, and extrapolate to how long it might last at some specified operating temperature. At 25C it will last nearly forever, which assumes that the LED has some form of cooling system. One can generate amazingly large and impressive numbers this way. Despite my derisive comments, it does work quite well when performed honestly and where the test parameters are sane.

For example, IEC 62717 and IEC 62722 LED life testing standards both demand 6,000 hrs of test time, with total output in lumens recorded every 1,000 hrs. Measuring lumens accurately requires an integrating sphere: which might explain why they don't just use a common light meter and why there are so few measurement points. Some detail on how Luxo specifies its lifetimes: I doubt if we will ever see detailed life test results from Costco LED's as you might from higher priced LED luminaires.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

They were probably using the US Total All Sectors figure from this page:

Reply to
Neill Massello

Thanks for finding that.

kind of wacko average as we pay a tiered system, where, in practice, the first tier is used up in the first week of the month, the second tier by the third week, and the next tier for the end of the month.

It goes up precipitously with each tier, and the tiers are the same for everyone, so they do NOT take into account anything specific like the number of bedrooms or bathrooms or square feet or even the number of people.

Reply to
Algeria Horan

Yikes Jeff!

You would bring up *more* complex LED-lifetime terms to figure out!

And, you would also find MARKETING BULLSHIT in the mix!

LM-80 = a standard for measuring LED lumen maintenance & depreciation LM-40 = time for 50% of the lamps in a large group to burn out L70 = time to degrade to 70% of its original lumens L80 = time to degrade to 80% of its original lumens L90 = time to degrade to 90% of its original lumens Reported TM-21 = predicts lifetime using LM80 + optimistic magic math Calculated TM-21 = predicts lifetime using LM80 + more optimistic magic math

Hence the "magic math" on the lifetime figures...

Seems to me that the "LED lifetime" figure everyone is quoting in this thread and in other threads is total bullshit, so far...

Well, I was sick of replacing very expensive non-standard Philips fluorescent bulbs, so I bought the LED light fixture from Costco just to get rid of the non-standard wacko shaped bulbs that kept burning out anyway.

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I asked Costco and the manufacturer to provide the information on the lifetime of the LED light that I did buy.

I didn't get anything more than "hey, the warranty is 5 years so that's how long it lasts".

What irks me is that they seem to never have run into someone who doesn't accept that bs as an "answer" to the question of how long the light fixture is expected to last.

I'm guessing the LED light fixture I bought lasts no longer than a couple sets of incandescent bulbs would have.

Time will tell.

Reply to
Algeria Horan

** The last until they fail or fade badly.

** The lighting industry is full of crooks, has been for decades.

Performance claims are simply made up by marketing pukes, not engineers.

Products are mainly made in China to the lowest possible cost and samples are rarely tested by anyone other than consumers.

Failing to live up to the claims made on the box is a LEGAL issue, not an electronics problem.

** Maybe that will shake a few of them up a bit.

Meanwhile you are just pissing in the wind.

.... Phil

Reply to
Phil Allison

root,

Believe it or not, the tests are designed to reflect real world usage.

You keep implying that there is something wrong with all advertised LED bulb lifetimes. Then you tell us you need to Google search to find out if that's true.

...

Jeff,

Actually, 3 years wouldn't be useful for anything but the decidedly "not realworld" test case of continuous use.

It would take considerably more than 3 years to test the common on at night, off during the day test case.

You could have left the word "inflated" out of that sentence. It's an insult to the rather clever testing that you described.

... snipped test description.

--
Dan Espen
Reply to
Dan Espen

Read the full report Appendix C. Then come back and tell us how unrealistic their numbers are.

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Dan Espen
Reply to
Dan Espen

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** Those fluoro lamps are for *commercial use* where they are either left on permanently or cycled once a day. The main wear out mechanism is to the filaments when starting.

Had one in your bathroom did you ?

.... Phil

Reply to
Phil Allison

Have you seen this?

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or

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Colin

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Reply to
Colin Horsley

Real world seems to *always* be less than advertised lifetime. At least for me they seem to be.

I'd be pleasantly surprised if LED bulbs last 5 years.

What fails? a. The electronics! b. The bulbs.

We know the manufacturers lie, or, more accurately, the MARKETING people, who make the labels, say only what they want you to think.

For example, they'll tell you an LED itself lasts 50,000 hours, but they won't tell you the "driver" lasts anywhere from zero to a couple of years.

The one thing about Jeff is that he's shown himself over the past decade to be a well-balanced person who is not swayed, like most people are, by exaggerated claims, whether they be any claim by Apple for their WiFi reception, or a bogus claim by LED manufacturers (such as the ones I received on the phone yesterday) as to lifetime.

He'll deny this though, as he doesn't like accolades, but he is always on the money, and, he almost always provides *proof*, something which you need to provide also in order for us to believe your claims (I'm not saying you didn't or don't provide proof - I'm just saying that Jeff almost always does

- so what he says carries weight).

Also, Jeff runs his own *tests* of tons of things, which are tests that most of us have never run, they're that detailed (ask him about router claims versus the real world some day!).

Jeff is like I am. We prove what we say, and we provide references, and photos and other reliable statistics. You'd need to do the same to hold water with us.

Anyway, fact is, I have a bulb, in my very hand, incandescent, that failed in two days.

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Notice the package says "1.4 year life".

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Reply to
Algeria Horan

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