On Mon, 31 Oct 2016 13:16:53 -0400, Michael Black wrote:

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

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).
http://cafecocina.com/whome/2015/11/...ceiling-lamps/

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: http://www.lightingfacts.com
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

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

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,

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.

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

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".

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 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.

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