How long do LED shop/ceiling lights really last at full outp

[Algeria Horan]

On Tue, 01 Nov 2016 00:27:31 -0400, Dan Espen wrote:

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

Dan,
You come across as challenging the facts, but, you provide few facts on your
own. It's easy to challenge, but it takes effort to back up your challenge.

I read my electricity bill.
Those are "my" facts.

I don't even have to show you my bill.
I'll simply point you to the PG&E Tiered Plan that I'm on:
https://www.pge.com/en_US/residential/rate-plans/rate-plan-options/tiered-base-plan/tiered-base-plan.page

Do you see *anything* anywhere near 10 cents?
Anything?

Look again:
https://www.pge.com/pge_global/local/images/data/en-us/rate-plans/rate-plan-options/how-tiers-work-graph.jpg

The first tier (which lasts about a week) is almost double that.
The next tier is almost triple.
And the fourth tier, the one that you use for the second half of the month,
or the last week, if you're frugal, is almost quadruple that.

Those are facts.
Do you dispute the facts?

What facts do you have for my rate that dispute that?

 

[Algeria Horan]

On Tue, 01 Nov 2016 10:59:44 -0400, Dan Espen wrote:

Anyway, fact is, I have a bulb, in my very hand, incandescent, that failed
in two days.
https://s15.postimg.org/92aoq3xej/burned_out_in_two_days.jpg

Notice the package says "1.4 year life".
https://s18.postimg.org/602tefda1/ge_bulb_burned_out.jpg

Do you honestly think that proves anything?

I understand your point, which is that I can say it lasted 10,000 years.
If I could prove it completely, and if it was worth the effort, I would,
just like Jeff *proved* that WiFi reception in routers was NOT what the
manufacturers claimed.

But you are like those people who say "prove it" to everything, which is
fine, but *you* have to provide some semblance of a reason to go to the
effort to prove things that we just have to accept on faith.

I was backing up your unproven claim that Jeff was not being balanced, in
effect, when I know, from the last decade on s.e.r and a.i.w that Jeff "is"
well balanced, and he proves what is worth proving.

I have 3 CFLs in a lamp post since 2000.
Just this year, one of them gave up the ghost.
They are activated when it gets dark.
So, they're on at least 12 hours a day, every day.
Construct some statistics out of that.

You entirely and completely missed the point.
Did you buy too many arguments this week?

All I was saying is that your claim against Jeff's veracity are completely
unfounded. You're entitled to your opinion, but if I asked you to prove that
you had sex with your wife five times this week, do I really expect you to
prove that?

What I'm saying is simply that your criticism of Jeff was unfounded, if you
look at the entire record. And, I'm saying that 11 cents per kilowatt hour
is a magical number entirely unachievable by me, in California.

If you claim otherwise, I'm only asking you to attempt to back up your very
own claims with fact, as I did with Jeff, and as I did with the price of
electricity in California.

 

[Algeria Horan]

On Tue, 1 Nov 2016 11:23:09 -0400, Meanie wrote:

When fluorescent lamps remain on all day, chances are you can
see 10 years on them. The average home will not see that life cycle
since it's not common to leave them on all day everyday.

I don't run statistics, but I appreciate what you wrote because my
fluorescent lamps don't last more than a year or two, it seems.

I used to mark the bulbs with a Sharpie, but I stopped doing that long ago.
I don't think I *ever* got anywhere near the claimed life.

But we turn them on and off a few times each day.

 

[Algeria Horan]

On Tue, 1 Nov 2016 11:18:11 -0400, Meanie wrote:

I understand your skepticism as a general consumer, but I've been
experiencing the products first hand.

This is good to know because the whole point of this thread is to nail down
the actual life of the lamps.

Of course, you can't expect me to NOT buy at Lowes or Ace or Home Depot, for
quantities such as we buy for a home as replacements, so the word 'quality
lamps' is to be taken with a grain of salt.

But at least it's good to know that you *understand* that an LED is never as
bright as it was on its first day, and that cycles, and heat, and vibration
exacerbate the existing cracks between crystals, such that LEDs drop off
exponentially in light output over time.

As stated in the standards that Jeff kindly referenced early on in this
thread, the diminished light output is very difficult to detect, since it
happens over time, and since there may be other bulbs compensating for the
lack of output, such that an LED bulb that has actually reached it's L70
lifetime may not be easily observed by you.

Nonetheless, if the driver failed, which I think can be the weakest point
(that premise needs to be explored), you'd know that. But you might not know
when any particular bulb has reached its L70 point without isolating the
bulb and actually measuring the output (since the gradual decline in output
isn't going to be suddenly noticeable, according to that report Jeff
referenced).

My point is that things failed, perhaps, and you don't realize it.
But that needs to be explored since you'd know of some failures (but not
all, unless the bulbs are isolated, and if you have a keen eye for such
things).

 

[Algeria Horan]

On Tue, 01 Nov 2016 09:08:01 -0700, Jeff Liebermann wrote:

LM-40 = time for 50% of the lamps in a large group to burn out

One more. ARL:
http://www.bulbs.com/learning/arl.aspx
"Average Rated Life (ARL) is how long it takes for half
the light bulbs in a test batch to fail"
I seem to recall others, but I'm too lazy to Google.

I remember reading in your prior reference that the time for half to fail
isn't useful for LEDs though, since they fail differently.

 

[Algeria Horan]

On Tue, 01 Nov 2016 09:02:59 -0700, Jeff Liebermann wrote:

> I should have guessed it was you.

Yeah, it's me.
My friends joke I'm half the Internet alone.

I'm always solving problems, asking questions, delving deeper, etc., as are
you (but you don't like to admit it).

I like to explain how things work,
without offering a judgment or opinion.

You have always been balanced, ever since I learned from you how to set up
my WiFi rooftop antenna on a.i.w years ago, when you still frequented that
forum (before you absconded to s.e.r that is).

And, you would also find MARKETING BULLSHIT in the mix!
It happens. I have some marketeering experience somewhere on my
resume.

Me too, truth be told (but I try to hide my curricum vitae far more so than
you do).

When I was in Marketing, we made hay with any advantage we could, and we
swept under the rug all the disadvantages. Plus we said things like "better"
and "new" and "more" since they couldn't be easily disputed.

Basically, we took whatever it was that the engineers gave us, and we
marketed the shit out of it, so that it *looked* like gold in the
literature.

But it was no different than anything else was.
Every good thing had a bad downside to it.

Like everything on this planet does.

Speaking of bullshit:
"How LED Lighting May Compromise Your Health"
http://articles.mercola.com/sites/articles/archive/2016/10/23/near-infrared-led-lighting.aspx

OMG. I'm losing out on all that healthy infrared radiation!
And that EMF is the "leading cause of blindness" in the USA!
Quick. Gimme one of those famous infrared saunas in Santa Cruz hippytown!

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

Nice summary. Sounds about right.

Thanks for noticing. I generally read all your references.
If you are gonna go to the trouble to reference them in a thread I authored,
I'm gonna go to the trouble to at least skim them (I read fast, very very
very fast, faster than most people can talk, and I type fast too, so it's
easy for me. When I was a kid, I was in a special reading program for the
gifted, where they had a machine that forced me to read faster and faster
and faster - dunno why my parents subjected me to that - but they did.)

I believe there are a few other
standards that I missed. Standards are a good thing. Every company
should have one.

I think the important point is that we each can pick the standard that makes
the most sense to us, but also, that information has to be readily available
to us.

I'm not sure yet, which is the readily available standard, but I'd prefer
the L70 myself, to be the standard that I get the information on.

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

Nope, because it's all we have to work with. Like I ranted, nobody
does 30,000 hr life tests. Therefore, nobody knows the "real world"
lifetime of an LED light.

At the moment, I'm guessing the one LED lamp I have will last no more than 4
or 5 years. (Call me up in 5 years and I'll let you know how it turned out.)

The best we can do is parametric testing,
accelerated life tests, and the usual guesswork. The first two are
quite valid and result in numbers that usually come fairly close to
reality. The guesswork, you can guess what I think.

Except that every once in a while, there will be failures in the drivers
that I don't think are being tested here. Are they?

It's much like MTBF (mean time between failure) which attempts to
estimate the life of a device based on historical tests and operating
conditions.

Understood.

These component estimates are conglomerated into a figure
for the device. However, the intent is not to estimate the lifetime,
but rather the number of expected failures in a population of LED's.

Makes sense.

"What Every LED Engineer Needs to Know About MTBF"
https://www.fairchildsemi.com.cn/Assets/zSystem/documents/collateral/whitepapers/LED-Lighting-MTBF-White-Paper.pdf
(Note: I haven't read through this yet)

The abstract mentions MTTF, which is essentially what I'm asking in this
thread, I believe, whereas MTBF is for repaired items (according to the
abstract).

It implies that we should use MTTF since we're gonna throw out the LED
fixture once it fails us.

That Fairchild paper goes into details (e.g., how to accelerate and what
happens if the failure rate is 0), but that's the net I take out of it by a
quick skim.

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.

For good reason. From the point of view of the manufacturer and
vendor, the ideal product blows up 1 day after the warranty expires.

The funny thing is that there are so many stupids out there who talk about
"warranties" as if they're NOT purely marketing bullshit!

On the car forums, I hear all the time people comparing batteries by their
warrantee, as if the warrantee conferred some magical quality on the
electrical and lifetime properties of the battery!

They even compare *tires* by warrantee! Geesuz.
It's sad how stupid people are, in general.
Very very sad.
Sigh.

I've ranted on the topic before, where simulation and modeling tools
are used to insure that multiple parts all fail just after some preset
time limit. My favorite example are GE(?) water heaters with 6, 9,
and 12 year warrantees, and roughly proportional pricing, but where
the only difference is the type and size of the anode rod. Details if
anyone wants them.

Interesting. Very interesting. I just had a water heater go, in fact, and,
um, I shouldn't say this, but I had never replaced the anode. All that was
left was some whitish stuff and the inner steel wire. The heater corroded in
7 years, but that was my fault for not replacing the anode (although it was
almost impossible to twist off, so, if you're gonna replace anodes, at least
crack the top hexnut every six months or so).

 

[Algeria Horan]

On Tue, 01 Nov 2016 16:06:15 GMT, Scott Lurndal wrote:

I understand your skepticism as a general consumer, but I've been
experiencing the products first hand.

This is good to know because the whole point of this thread is to nail down
the actual life of the lamps.

Which is impossible to do based on unreliable anecdotal evidence in
an usenet newsgroup read by perhaps a hundred people.

Fair enough point.

 

[Algeria Horan]

On Tue, 01 Nov 2016 16:10:25 GMT, Scott Lurndal wrote:

How does the cost of a Kwh contribute to the rated lifetime
of an LED-based illumination device?

Good point. I don't even remember how we got into the costs, other than I
made a joke that I'd love to live in Louisiana where the costs actually were
listed as around that amount.

I smell a red-herring.
Costs of electricity vary widely nationwide. Yes, California
has more expensive electricity (specifically to encourage conservation)
than other parts of the country, but that is not a factor in
rated lifetime.

Agreed.
We're talking actual lifetime of the LED "unit" (which includes whatever can
be replaced, which, for a household unit, is usually the driver and chips
and the housing, all in one package like my Costco setup).

Tj and cycles (on/off) would seem to be the two major controlling
factors, just as they are for incandescents.

Interestingly, the paper Jeff originally cited mentioned three main factors,
all of which exacerbated existing physical cracks between crystals:
1. Cycles
2. Heat
3. Vibration

To that, Jeff noted his bathroom fixture had a few more, mainly:
a. Humidity/moisture
b. Dust & orientation (aka heat retention or dissipation)
c. Voltage variations (e.g., we have *many* power outages per year here)

I'm only about 30 miles from Jeff (give or take) but we lose our power so
often that I don't know of many people who don't have a built-in generator
out here (plus we need the power to pump the water to fill our sinks).

So, overvoltage is key here. Very key. (I have holes blown in some of my
appliances, for example - even though I can't prove what caused it -
certainly I can see the burn marks and the high failure rate of fixed
appliances.)

 

[Algeria Horan]

On Tue, 01 Nov 2016 09:33:24 -0700, Jeff Liebermann wrote:

you're entitled to invent a new testing standard, along with yet
another collection of artificial test conditions, that will satisfy
your vision of a "real world" test.

Fair enough response.

I've only had three LED light
failures. All were in the bathroom, all were failures of the driver
electronics

I believe that.
I suspect, but without personal experience, that the LED drivers are the
weak link in the LED setup. I haven't looked at one yet, but a single
electrolytic cap would tell me as much. I know you know electronics well, so
you'd know more of what to look for, but, I know wet caps dry out (among
other things that go poof over time).

two were mounted inverted (base up), and all were
retrofitted into incandescent fixtures with miserable ventilation.
Therefore, I propose a bathroom LED test, which includes heat,
condensing and non-condensing humidity, on-off cycle time, over
voltage, erratic power glitches by PG&E, limited ventilation, and dust
accumulation. Such a test will clearly define what might be expected
from "typical" bathroom LED service. The EU micro managers have specs
and tests for almost everything and will surely appreciate your
efforts on their behalf.

Yup. You had 'em all, especially:
- Heat
- Cycles
- Humidity (which wasn't mentioned in the previous articles)
- Overvoltage (which also wasn't mentioned, but happens all the time)
etc.

> I think you need a major dose of testing reality.

Fair enough assessment.

Instead of LED's,
let's try drug testing. In order to release a new drug, one of the
tests that a pharmaceutical company must survive is a cancer test.

I have one degree in the life sciences, so, I'm familiar with details.

> For LED testing, much the same trick is used.

I have another degree in engineering, so, again, I'm familiar with details
(remember, I invited you to the inventors club, long ago?).

There are quite a few products that suffer from inflated
specifications.

Ummm... er.... almost *all* products suffer from inflated specs.
You know this from looking at anything built by Apple, for example.

Eventually, they run out of
these fringes, and start inflating the specifications on the
assumption that the typical customer doesn't understand the specs.

Yup. I was in marketing myself.
The stupids outnumber the intelligent parsers 10,000 to one.

There are still people who believe Techron (aka polyetheramines) are
something special to Chevron, for example, or that high-octane fuel is
somehow (magically?) better than regular octane fuel.

Or, that a battery with a longer warrantee is somehow, electrically, better
than a battery with a shorter warrantee.

Back to LED lifetime claims, I'm shooting for 4 or 5 years.
If my one LED fixture meets that expectation, I'll be happy as the Philips
wacko sized fluorescents lasted 1/4 that each time, until I got sick of
replacing them.

 

[Dan Espen]

Algeria Horan <algeriahoran@algeria.horan.net> writes:

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.

See Appendix C as I stated in my other post.
Then tell me how your methods are so superior to those used by
the experts.

Anyway, fact is, I have a bulb, in my very hand, incandescent, that failed
in two days.
https://s15.postimg.org/92aoq3xej/burned_out_in_two_days.jpg

Notice the package says "1.4 year life".
https://s18.postimg.org/602tefda1/ge_bulb_burned_out.jpg

Do you honestly think that proves anything?

I have 3 CFLs in a lamp post since 2000.
Just this year, one of them gave up the ghost.
They are activated when it gets dark.
So, they're on at least 12 hours a day, every day.
Construct some statistics out of that.

--
Dan Espen

 

[Meanie]

On 11/1/2016 10:11 AM, Algeria Horan wrote:

On Tue, 01 Nov 2016 00:14:43 -0400, Dan Espen wrote:

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

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.

I can assure you, we replaced incandescent floodlights back in 2010 with
LEDs in one of our buildings. These lights are on 8 to 10 hours a day,
if not longer and we've yet to replace any of them (over 50).


I understand your skepticism as a general consumer, but I've been
experiencing the products first hand. I've been dealing with LEDs for
many years and I agree, they do diminish in brightness after their
manufactured rating, the quality lamps last up to their claim if not
longer. Of course, we don't purchase the cheap ones you buy at Home Depot.

 

[Meanie]

On 11/1/2016 10:59 AM, Dan Espen wrote:

Algeria Horan <algeriahoran@algeria.horan.net> writes:

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.

See Appendix C as I stated in my other post.
Then tell me how your methods are so superior to those used by
the experts.

Anyway, fact is, I have a bulb, in my very hand, incandescent, that failed
in two days.
https://s15.postimg.org/92aoq3xej/burned_out_in_two_days.jpg

Notice the package says "1.4 year life".
https://s18.postimg.org/602tefda1/ge_bulb_burned_out.jpg

Do you honestly think that proves anything?

I have 3 CFLs in a lamp post since 2000.
Just this year, one of them gave up the ghost.
They are activated when it gets dark.
So, they're on at least 12 hours a day, every day.
Construct some statistics out of that.

That is the reason they last so long. What people don't realize is the
life of fluorescent, whether tubes or CFL, is shortened when they are
subject to constant on and off. They are not made for constant on/off
action unless the fixture contains a "program start" ballast. Due to the
cost of that ballast, they will not be within the common hardware store
fixture. When fluorescent lamps remain on all day, chances are you can
see 10 years on them. The average home will not see that life cycle
since it's not common to leave them on all day everyday.

 

[Jeff Liebermann]

On Tue, 1 Nov 2016 02:38:46 +0000 (UTC), Algeria Horan
<algeriahoran@algeria.horan.net> wrote:

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

I should have guessed it was you. I like to explain how things work,
without offering a judgment or opinion. This type of question really
belongs in Candlepower Forums.

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

It happens. I have some marketeering experience somewhere on my
resume. Speaking of bullshit:
"How LED Lighting May Compromise Your Health"
<http://articles.mercola.com/sites/articles/archive/2016/10/23/near-infrared-led-lighting.aspx>

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

Nice summary. Sounds about right. I believe there are a few other
standards that I missed. Standards are a good thing. Every company
should have one.

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

Nope, because it's all we have to work with. Like I ranted, nobody
does 30,000 hr life tests. Therefore, nobody knows the "real world"
lifetime of an LED light. The best we can do is parametric testing,
accelerated life tests, and the usual guesswork. The first two are
quite valid and result in numbers that usually come fairly close to
reality. The guesswork, you can guess what I think.

It's much like MTBF (mean time between failure) which attempts to
estimate the life of a device based on historical tests and operating
conditions. These component estimates are conglomerated into a figure
for the device. However, the intent is not to estimate the lifetime,
but rather the number of expected failures in a population of LED's.
"What Every LED Engineer Needs to Know About MTBF"
<https://www.fairchildsemi.com.cn/Assets/zSystem/documents/collateral/whitepapers/LED-Lighting-MTBF-White-Paper.pdf>
(Note: I haven't read through this yet)

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.
http://uk.rs-online.com/web/p/non-integrated-compact-fluorescent-lamps/4075597/

600lumens / 9watts = 67 lumens/watt. Barf.
Philips claims 200 lumens/watt and Cree claims 300 lumens/watt:
<http://www.philips.com/consumerfiles/newscenter/main/design/resources/pdf/Inside-Innovation-Backgrounder-Lumens-per-Watt.pdf>
<http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier>
You may not see that at Costco for a while, but maybe if Philips and
others get back into the LED biz.
<http://www.memoori.com/samsung-joins-philips-siemens-in-led-lighting-exodus/>
It's not too obvious, but both claims assume that the LED is cooled to
approximately room temperature.

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.

For good reason. From the point of view of the manufacturer and
vendor, the ideal product blows up 1 day after the warranty expires.
I've ranted on the topic before, where simulation and modeling tools
are used to insure that multiple parts all fail just after some preset
time limit. My favorite example are GE(?) water heaters with 6, 9,
and 12 year warrantees, and roughly proportional pricing, but where
the only difference is the type and size of the anode rod. Details if
anyone wants them.

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

Talk to me in 30,000 hrs and we'll compare notes.

>Time will tell.

You have a talking clock?

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Scott Lurndal]

Algeria Horan <algeriahoran@algeria.horan.net> writes:

On Tue, 1 Nov 2016 11:18:11 -0400, Meanie wrote:

I understand your skepticism as a general consumer, but I've been
experiencing the products first hand.

This is good to know because the whole point of this thread is to nail down
the actual life of the lamps.

Which is impossible to do based on unreliable anecdotal evidence in
an usenet newsgroup read by perhaps a hundred people.

 

[Jeff Liebermann]

On Tue, 01 Nov 2016 09:02:59 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

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

One more. ARL:
<http://www.bulbs.com/learning/arl.aspx>
"Average Rated Life (ARL) is how long it takes for half
the light bulbs in a test batch to fail"
I seem to recall others, but I'm too lazy to Google.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Scott Lurndal]

Algeria Horan <algeriahoran@algeria.horan.net> writes:

On Tue, 01 Nov 2016 00:27:31 -0400, Dan Espen wrote:

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

Dan,
You come across as challenging the facts, but, you provide few facts on your
own. It's easy to challenge, but it takes effort to back up your challenge.

How does the cost of a Kwh contribute to the rated lifetime
of an LED-based illumination device? I smell a red-herring.
Costs of electricity vary widely nationwide. Yes, California
has more expensive electricity (specifically to encourage conservation)
than other parts of the country, but that is not a factor in
rated lifetime.

Tj and cycles (on/off) would seem to be the two major controlling
factors, just as they are for incandescents.

Tj = Junction Temperature.

 

[Jeff Liebermann]

On Tue, 01 Nov 2016 00:14:43 -0400, Dan Espen <despen@verizon.net>
wrote:

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

Well, you're entitled to invent a new testing standard, along with yet
another collection of artificial test conditions, that will satisfy
your vision of a "real world" test. I've only had three LED light
failures. All were in the bathroom, all were failures of the driver
electronics, two were mounted inverted (base up), and all were
retrofitted into incandescent fixtures with miserable ventilation.
Therefore, I propose a bathroom LED test, which includes heat,
condensing and non-condensing humidity, on-off cycle time, over
voltage, erratic power glitches by PG&E, limited ventilation, and dust
accumulation. Such a test will clearly define what might be expected
from "typical" bathroom LED service. The EU micro managers have specs
and tests for almost everything and will surely appreciate your
efforts on their behalf.

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

I think you need a major dose of testing reality. Instead of LED's,
let's try drug testing. In order to release a new drug, one of the
tests that a pharmaceutical company must survive is a cancer test.
This is usually done with mice or rats. However, they're not ordinary
mice or rats. If such a cancer test were performed on the common and
ordinary breeds of mice and rats, the number of tumors found would be
very small and therefore statistically useless. In order to get
statistically significant numbers, mice and rats that are genetically
predisposed to developing cancerous tumors are used.

For LED testing, much the same trick is used. If you don't have a
sufficient number of failures during the test period, and you can't
extend the test period, you do whatever it takes to produce those
failures. The easiest is to elevate the temperature. For
incandescent lamps, raising the filament voltage also works. By
plotting a trend line of different temperatures or voltages, one can
extrapolate the graph to obtain a fairly good approximation of the
expected lifetime at more sane temperatures and voltages. That's how
one avoids multi-year tests.
<http://www.powerelectronictips.com/seeing-light/>

Instead, they run a HALT
(Highly Accelerated Life Test), which is faster, and presumably
produces the necessary inflated figures:

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

There are quite a few products that suffer from inflated
specifications. Battery capacity (in particular 18650 cells),
flashlight output in lumens, wi-fi range/speed, laptop battery life,
laser printer toner cartridge pages, inkjet cartridge pages, etc. All
of these are characterized by inflated claims contrived to make the
numbers bigger. I can explain any of these in detail if you want to
know how it works. The reasons are competitive pressure and product
differentiation. Every manufacturer and vendor are trying to sell on
the basis of everything except price. So, they push service,
warranties, packaging, bonus junk, etc. Eventually, they run out of
these fringes, and start inflating the specifications on the
assumption that the typical customer doesn't understand the specs. I
think this thread demonstrates that this is true. Instead of
inflated, perhaps "grossly exaggerated" might be more accurate.

>... snipped test description.

Sniff...

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Dan Espen]

Algeria Horan <algeriahoran@algeria.horan.net> writes:

On Tue, 01 Nov 2016 00:27:31 -0400, Dan Espen wrote:

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

Dan,
You come across as challenging the facts, but, you provide few facts on your
own. It's easy to challenge, but it takes effort to back up your challenge.

I read my electricity bill.
Those are "my" facts.

You've still failed to challenge any of the methodology listed in
Appendix C.

I'm not challenging any facts. I know damn well I don't have any.
All I have is my own experience. Those would be anecdotes, not data.

But unlike yourself, I don't go around saying the experts are wrong.
I look at the source, the methodology, think about any motivation
the source may have to falsify and judge who to believe.

If that chart shows an average price for California that doesn't
square up with your experience, then maybe other consumers in
California pay less. What you see on your bill is irrelevant
to the average price of electricity in California.

So, you started out with the completely specious claim that
LED lifetime was for the LED component and not the driving
electronics. That is still ridiculous.

LEDs work and work well. Most people can buy them and never
have to change the bulb again. You running around making
blind assertions isn't going to change any of that.

So, how long to shop/ceiling lights _really_ last?
Why not read the package and believe what it says?
If you want to challenge the published numbers,
it stands to reason, you have to use better methodology
than that shown in Appendix C. Good luck with that.

--
Dan Espen

 

[Jon Elson]

Jon Elson wrote:

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.

OK, looked up my records. My first prototype was a 10 LED array with my own
power supply (LED switching current regulator chip) running 300 mA. This
has been in heavy use in our utility room since april 2013. Absolutely no
sign of dimming. I'd guess that's gotten over 6000 hours of use.

Then, I built a 20-LED string to retrofit a dual fluorescent tube fixture in
our kitchen, and put that in in January 2014. A second string went in in
April 2014.
These are powered from a commercial LED lighting power supply at 350 mA.
I'd guess the older one of these may have accumulated up to 8000 Hours of
operation. It is possible these have dimmed SLIGHTLY, I have one standard
dual-tube fluorescent left that I haven't gotten around to retrofitting yet
to compare to. But, the pattern of light output is different enough that
any comparison is pretty subjective.

Anyway, I'm sure happy with the results. I cut power consumption from 103 W
down to 21 W, with perhaps a SLIGHT reduction in light output. Those 48"
T12 tubes are getting pricy, and it seems by reducing mercury content, the
lifetime has been reduced, too.

Now, these are NOT commerical off-the-shelf LED lighting products. See
http://pico-systems.com/Lighting.html
for some description and a picture. (That picture, by the way, is by camera
flash, the LEDs are OFF, or the picture would have been BADLY overexposed,
the LEDs are insanely bright if you look at them without the diffuser.)
The trick is the several square inches of PC board copper per LED acts as a
heat sink and keeps the LEDs from overheating. If a commercial fixture or
bulb doesn't address this, then the lamps will have a short life.

Jon