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By anonimouse (Mon Jun 10, 2013 at 05:27:43 AM EST) (all tags)
25 year lifespan? Hah!!


I have a set of 4 GU10 bulbs in the kitchen and a similar set in the bathroom. The latter set are in totally enclosed units for bathroom fitting compliance. I bought a set of 4 Tesco 6W GU10 bulbs for them, but I've had to swap 3 of the four in the bathroom over the last year.

The good thing about this is that the swapsies are free due to the fact I can point to the claimed 25 year lifespan and get a freebie as a result.

So is it that Tescos are shipping crappy LED bulbs or is it more likely that I has an electric problem?
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LED Bulbs | 22 comments (22 topical, 0 hidden) | Trackback
Those options aren't mutually exclusive by lm (2.00 / 0) #1 Mon Jun 10, 2013 at 05:52:24 AM EST
First, understand that the "life" on the LED bulb is a statement about how long the LED will emanate light at 70 percent of its stated lumens. But if the bulbs are failing all together, it's probably not the LED itself but the circuitry that transforms AC current into DC current. There are industry wide quality problems with that. 

There is no more degenerate kind of state than that in which the richest are supposed to be the best.
Cicero, The Republic
Lifespan by anonimouse (2.00 / 0) #2 Mon Jun 10, 2013 at 06:14:50 AM EST


They're claimed to last 25 years whilst being on for about 2.7 hours a day.  If they output 70% of their light after this length of time I'd have no complaints.

Personally I'd be happy if they lasted 5 or 6 years.

I have some of the older tech 1W LEDs which have survived for a long time


Girls come and go but a mortgage is for 25 years -- JtL
[ Parent ]
Right by lm (2.00 / 0) #13 Mon Jun 10, 2013 at 09:38:02 AM EST
But in this case, you're looking at the lifespan of the LED but it is the lifespan of the circuitry that the LED sits on that is the problem.

Unfortunately, for units made to be fitted on old older light fixtures, the circuitry in question is mass produced and of notoriously poor quality across the industry.


There is no more degenerate kind of state than that in which the richest are supposed to be the best.
Cicero, The Republic
[ Parent ]
Notoriously poor? by wiredog (2.00 / 0) #14 Mon Jun 10, 2013 at 10:27:38 AM EST
They've forgotten how to make rectifiers? Damn.

Earth First!
(We can strip mine the rest later.)

[ Parent ]
It's a bridge too far [n/t] by Herring (4.00 / 2) #15 Mon Jun 10, 2013 at 10:44:07 AM EST


christ, we're all old now - StackyMcRacky
[ Parent ]
Not so much forgotten how ... by lm (4.00 / 1) #16 Mon Jun 10, 2013 at 11:08:15 AM EST
... as can't be arsed to do proper quality control for mass production.

Quotes from an industry panel on the topic:

``We’re entering a world where you will find on the shelf low, very bad, better (and) higher quality bulbs.''

``failures tend to stem from a breakdown of components within the bulb other than the bulb’s LED''

http://www.smartplanet.com/blog/intelligent-energy/when-good-lights-go-bad-led-breakdown/6204

That math ends up being pretty simple. Most manufacturers calculate that fewer than 1 out of 10 people will bother exchanging a dud. So they can easily calculate whether or not increasing build quality by $x will save them money over honoring their warranty.

If I lived in a house rather than an apartment, I'd get fixtures designed to house LED bulbs rather than LED bulbs designed for incandescent light fixtures. In all actuality, the LED itself probably would last 25 years so long as the fixture was of decent quality.


There is no more degenerate kind of state than that in which the richest are supposed to be the best.
Cicero, The Republic
[ Parent ]
Considering the main component by wumpus (4.00 / 1) #22 Tue Jun 11, 2013 at 07:25:53 AM EST
will rectify, I'm guessing that issue is more regulation. Actually, what you want is more constant voltage, and capacitors of that size are known for lifespan issues. I'm guessing that the age is capacitor limited.

Wumpus

[ Parent ]
Tesco hardware really is a mixed bunch by ambrosen (2.00 / 0) #20 Mon Jun 10, 2013 at 03:06:33 PM EST
Sometimes they source normally high-margin products and sell them and their usual margin, so for example, I'm very pleased with my Freeview HD box, which was £30 a few years ago, and my £15 knife block works fine, but then there's some things I've bought from them which were just crap, like, it appears, those LEDs.

Also, moisture might not have been too kind to them.

[ Parent ]
I have a theory. by Herring (4.00 / 1) #3 Mon Jun 10, 2013 at 06:24:32 AM EST
Years ago, it was decreed that there should be a standard mains voltage across the EU so stuff would work everywhere. It was 220V most places and 240V in the UK and that was a pain. Rather than actually standardize the voltage, they simply declared it to be 230V +- 10%. Problem solved.

Except that as a lot of people have noticed, fluorescent bulbs etc. - in fact most electrical appliances last far longer on the continent than in the UK.

Incidentally, I did test at home:
This is not safe

christ, we're all old now - StackyMcRacky

And... by ana (4.00 / 1) #5 Mon Jun 10, 2013 at 06:44:14 AM EST
the two empty wine bottles and two beer cans had nothing whatever to do with the interpretation of the results. :-) 

I now know what the noise that is usually spelled "lolwhut" sounds like. --Kellnerin

[ Parent ]
It's art by Herring (4.00 / 2) #6 Mon Jun 10, 2013 at 06:47:16 AM EST
I call it "Still life with multimeter".

christ, we're all old now - StackyMcRacky
[ Parent ]
Yes by gazbo (4.00 / 3) #11 Mon Jun 10, 2013 at 08:27:46 AM EST
After two wines, two cans of wifebeater and a Duvel chaser, I too have ideas like sticking metal prongs into mains sockets.

I recommend always assuming 7th normal form where items in a text column are not allowed to rhyme.

[ Parent ]
This is why by Herring (4.00 / 4) #12 Mon Jun 10, 2013 at 09:21:00 AM EST
I had a couple of water biscuits to soak it up.

christ, we're all old now - StackyMcRacky
[ Parent ]
Isn't that a spirits bottle behind the Duvel? by ambrosen (2.00 / 0) #19 Mon Jun 10, 2013 at 02:58:32 PM EST
I take it that was from a previous day.

[ Parent ]
Onto the money by bobdole (2.00 / 0) #7 Mon Jun 10, 2013 at 06:49:30 AM EST
You are still probably onto the money, if I remember correctly 5% change in voltage (from rated) is by rule of thumb halving/doubling the rated filament life.

It's not linear, but at 10-20v over what the filament was rated for, you would probably see <50% longevity.

In the case of the anonymous mouse, there was something about mounted inside some furniture(?)... bathrooms often having both unfriendly climate and banging closet doors (or similar) banging the bulbs regularly, there is no way any quality bulb would last the specified period.
-- The revolution will not be televised.

[ Parent ]
LED bulbs are ceiling mounted by anonimouse (2.00 / 0) #9 Mon Jun 10, 2013 at 06:54:49 AM EST
...in enclosed units. Should not be a problem


Girls come and go but a mortgage is for 25 years -- JtL
[ Parent ]
Heat? by hulver (4.00 / 1) #4 Mon Jun 10, 2013 at 06:40:00 AM EST
If they're enclosed then they'll heat up more.
--
Cheese is not a hat. - clock
Shouldn't be a problem by anonimouse (2.00 / 0) #8 Mon Jun 10, 2013 at 06:53:43 AM EST
The light fitting is supposed to dissipate heat from 4x50W GU10 bulbs so it shouldn't have a problem with 4x6W LEDs


Girls come and go but a mortgage is for 25 years -- JtL
[ Parent ]
Easy to measure by lm (2.00 / 0) #17 Mon Jun 10, 2013 at 11:09:44 AM EST
Sick a thermometer in the fixture and leave the lights on for an hour. Check the temp. Then compare that to the temp tolerances on the package.

There is no more degenerate kind of state than that in which the richest are supposed to be the best.
Cicero, The Republic
[ Parent ]
The voltage converters can get hot. by ObviousTroll (2.00 / 0) #21 Mon Jun 10, 2013 at 10:44:22 PM EST
I have this problem with CFLs; I tried several brands in my ceiling fixtures and table lamps, the electronics fried in all of the ceiling fixtures after a year or so, but the lamps have lasted years. 

An Angry and Flatulent Pig, Trying to Tie Balloon Animals
[ Parent ]
It is heat by jaxom green (4.00 / 1) #10 Mon Jun 10, 2013 at 08:12:27 AM EST
Despite noting that the fixture is supposed to be able to dissipate heat from standard bulbs the cause of premature failure is likely heat.  LED bulbs are MUCH more sensitive to heat than traditional bulbs.  They can still be cool enough to handle but be warmer than their operating range.  Enclosed fixtures don't allow enough air flow around the LED bulb's cooling mechanism.  Airflow is vital to keeping the bulb cool enough.

http://en.wikipedia.org/wiki/Thermal_management_of_high-power_LEDs



Cheers by anonimouse (2.00 / 0) #18 Mon Jun 10, 2013 at 12:16:09 PM EST
Thanks for the linky. Will keep that quiet if'/when I need replacements.


Girls come and go but a mortgage is for 25 years -- JtL
[ Parent ]
LED Bulbs | 22 comments (22 topical, 0 hidden) | Trackback