The big ebay LED floodlight scam.

[westfw]

The external power meter should be OK for proof.  a 20W lamp should not meter at less than 10W...

I bought an LED desk lamp some time ago, which I think claimed 10W and was powered by a wall-wart clearly marked as providing less than 10W.  However, it is "just right" for the purpose I had intended, so that's OK with me.  (In fact, I wish I could get more.  But they disappeared from the store...)

It does seem odd that the under-rated part is the power supply, rather than the LED itself.  I would think that the LED would be the more expensive part.  (perhaps they are "reject" 20W LEDs whose failure modes are not visible at 10W?)

[Corporate666]

The external power meter should be OK for proof.  a 20W lamp should not meter at less than 10W...

I bought an LED desk lamp some time ago, which I think claimed 10W and was powered by a wall-wart clearly marked as providing less than 10W.  However, it is "just right" for the purpose I had intended, so that's OK with me.  (In fact, I wish I could get more.  But they disappeared from the store...)

It does seem odd that the under-rated part is the power supply, rather than the LED itself.  I would think that the LED would be the more expensive part.  (perhaps they are "reject" 20W LEDs whose failure modes are not visible at 10W?)

Some enterprising Chinese seller will figure out that putting a 30W power resistor in the housing and selling 30W LED lights (that actually draw 20W) will let him rebadge them as super awesome 50W lights! 

[Rufus]

Some enterprising Chinese seller will figure out that putting a 30W power resistor in the housing and selling 30W LED lights (that actually draw 20W) will let him rebadge them as super awesome 50W lights! 

Yep the same way you can find lumps of concrete being used as PFC chokes.

http://www.hardwaresecrets.com/blog/hantol-psu-fake-pfc-made-of-cement/220

[Simon]

I bought these: http://www.ebay.co.uk/itm/361102408826?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT utter garbage, they claim 27W because of the amount of LED's installed but even their power consumption claims do not match up. When I tested them they were well out, at 10V they draw 7W and at most at around 14V they draw 18-19W and by 15.5V the current draw is dropping so clearly already up to full power.

[free_electron]

[que chinese accent] a you westen people alway complain abou chinee produc. is very efficien . 20 watt led only draw 10 watt. westen produc no tha efficien ! [/end chinese accent]

[mrflibble]

[que chinese accent] a you westen people alway complain abou chinee produc. is very efficien . 20 watt led only draw 10 watt. westen produc no tha efficien ! [/end chinese accent]

That's racialist, that is!

[dannyf]

It depends on how the "wattage" is defined.

It is not uncommon (actually, almost universal), for example, for a CFL bulb consuming 6w of electricity to be labeled 60w for its ability to generate the same light as a 60w incandescent light bulb. This makes it easier for consumers to cross-shop light bulbs and makes the marketing easier too.

You don't have to agree to its approach but you would be a fool for not recognizing its merit.

[Kjelt]

If it is legit the product should be labelled "equivalent to a xx W incandescent bulb" or a graphic that is synonomous to that.
But I am amazed that educated people here still buy those  garbage products but warn everybody not to buy semiconductors from those sites  . Wakeup call, leds are semiconductors don,t buy them there since the specs won,t be right, half is from the garbagecan of the local factory.

[dannyf]

Yeah. Some of them are genuinely surprised when their purchases at "incredibly low prices" turn out too good to be true, :0

Those people are so smart that they are stupid.

[Simon]

It depends on how the "wattage" is defined.

It is not uncommon (actually, almost universal), for example, for a CFL bulb consuming 6w of electricity to be labeled 60w for its ability to generate the same light as a 60w incandescent light bulb. This makes it easier for consumers to cross-shop light bulbs and makes the marketing easier too.

You don't have to agree to its approach but you would be a fool for not recognizing its merit.

It's time to abandon the concept of output watts of a lightbulb and use the correct definition of efficacy in producing light: the lumen! while most will complain that lumens could be too hard to explain the truth is that a complete switch to lumens would end all of the dodgy labelling. You can label something as equivalent to the same output as something else (that is undefined) in W but that hardly ties the manufacturer down and is seen as a guide. Being made to state lumens + colour temperature would fix a standard that never need changing again!

Of course such transparency is not in the interests of manufacturers. All we need is for the eu to stop worrying about vacuum cleaners that hardly get used and publish a standard of lumens to old incandescent watts and then abandon any labelling in terms of wattage as an indication of light output which it is not.

[Paul Moir]

Contra argument there Simon:  lumens are worthless.

For example, I can give you 500 lux via a sodium vapour lamp no problem with awesome efficiency.  Trouble is it'll all be at 590nm which doesn't work well for seeing certain things.  IMO, efficacy cannot be reduced to intensity at all.  You have to consider what you want done with the energy.

I'll give you another more radical example.  What if I gave you 1000 lux at 1000nm.  Not very bright huh?

(Obviously I deal with short-sighted standards that work in "scientifically" defined values without considering the desired effect.   )

[Towger]

For example, I can give you 500 lux via a sodium vapour lamp no problem with awesome efficiency.  Trouble is it'll all be at 590nm which doesn't work well for seeing certain things.  IMO, 

That's why all bulbs should have their CRI (colour rendering index) on the box as well.... Que another argument re CRI.

[Simon]

Contra argument there Simon:  lumens are worthless.

For example, I can give you 500 lux via a sodium vapour lamp no problem with awesome efficiency.  Trouble is it'll all be at 590nm which doesn't work well for seeing certain things.  IMO, efficacy cannot be reduced to intensity at all.  You have to consider what you want done with the energy.

I'll give you another more radical example.  What if I gave you 1000 lux at 1000nm.  Not very bright huh?

(Obviously I deal with short-sighted standards that work in "scientifically" defined values without considering the desired effect.   )

That is why i said lumens + colour temperature. You know many crap compact fluorecents there are out there that are 20W and marked as equivalent to 100W but put out barely visible yellow light (2700K) ? I was exmplasining the very point to someone at work yesterday morning, I could give them a 100W IR light and cliam on the box 100W but it would mean sod all.

I replaced 1 23W CFL with 1 10W LED light, So i guess that CFL was not much cop, it may have used 23W but what the hell it did with it is unknown.

[Simon]

As an example see these two ebay listings, and the lumens and the watts, complete contradiction...... the the system of equivalent wattage is probably not official and anyone can put anything they like as you can argue know end what the power should be.

http://www.ebay.co.uk/itm/3W-B22-Bayonet-Candle-2835SMD-LED-Bulb-280-Lumen-Warm-White-Like-30W-/221378601265?_trksid=p2054897.l4275

http://www.ebay.co.uk/itm/B22-12-SMD-LED-2-5W-180LM-Warm-White-Dimmable-Candle-Bulb-40W/330878217417?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D28111%26meid%3D7ee2bdfc4afc410083a854a4377f077d%26pid%3D100005%26prg%3D11472%26rk%3D4%26rkt%3D6%26sd%3D221378601265&rt=nc

[dannyf]

lumens are worthless.

So now you need four engineering degrees to buy a light bulb?

That's why sometimes people can be too smart for their own good.

[Simon]

lumens are worthless.

So now you need four engineering degrees to buy a light bulb?

That's why sometimes people can be too smart for their own good.

You should not need 4 degrees. But to be certain that what your buying will do what it says on the tin you do need to know a thing or two because the marketing wank has been allowed to get into specs and governments don't care to legislate on what can be sold and what it can be called.

Lumen's are far more useful than watts. Maybe in the days of only incandescents watts was enough but ever since the existence of fluorescents it has lost it's usefulness. But the general public and legilation are always years if not decades behind a technology.

Lumen's describes actual light output, watts does not, so it's a much better measure. You will need to add to that colour temperature at the very least.

Of course if you don't want to have to think for yourself you can demand that your government carries out checks and controls on all imports and manufacturing as used to be the case.

People so love to blame and criticise new ideas and technologies when in actual fact the problem is that all manufacturers and retailers care about is their profits and they actively don't care about quality and standards.

There is no point in shooting the messenger! What you need 4 degrees for is to reverse engineer the marketing bollocks wank advertising and outright lies.

[HighVoltage]

So, what LED lights can be recommended.
Is there a brand or supplier tat can be trusted.
Or can you say in general that all low cost LED lights on ebay are junk?

[dannyf]

I have some cree 60w/75w bulbs and they seem to be holding up well. I however doubt they are that efficient as the bulbs get pretty hot after a short period of usage.

can you say in general that all low cost LED lights on ebay are junk?

With "in general" and "all" there, that's an impossible to answer question.

I don't think it is true that all low cost LED lights on ebay are junk; I do think that most of them are junk, however.

I would further amend it to say that you should assume that they are junk unless proven otherwise. That way, you will never be pissed off by your purchases,

[Zero999]

I'll give you another more radical example.  What if I gave you 1000 lux at 1000nm.  Not very bright huh?

That's impossible because lux takes into account the sensitivity of the human eye which is 0 at 1000nm: you'll cook your retina before you'll see it!
http://en.wikipedia.org/wiki/Lux

[Simon]

I would further amend it to say that you should assume that they are junk unless proven otherwise. That way, you will never be pissed off by your purchases,

Correct, if they have stated specs and they are reasonable there is a chance they are ok. If there are no specs or they are outlandish then obviously they are junk.

[Kjelt]

You need a $100k sphere and calibrated equipment to correctly measure lumens.
You can say almost anything on Ebay no-one who can correctly verify it, if a brand name like Philips, GE, Osram and the likes put a lumen rating on their product you know what you get.
A lot of dubious products on Ebay not only do not live up to the claimed specs they are a life threatening unsafe product and a possible fire hazzard (as the floodlight with the glued grounding prooves).
You are better off buying the genuine led parts and create your own ledlamps maybe not 230VAC but 12VDC instead of throwing your money away gambling at Ebay

[Simon]

You generally get what you pay for and amazon is now just another ebay except much of it is backed by amazon and they give that much of a shit that they won't pay tax or pay their employees decently so you can't really trust them to choose quality products can you ?

[Zero999]

You need a $100k sphere and calibrated equipment to correctly measure lumens.

But it's possible to use a basic light meter to give you a ballpark.

You can say almost anything on Ebay no-one who can correctly verify it, if a brand name like Philips, GE, Osram and the likes put a lumen rating on their product you know what you get.
A lot of dubious products on Ebay not only do not live up to the claimed specs they are a life threatening unsafe product and a possible fire hazzard (as the floodlight with the glued grounding prooves).
You are better off buying the genuine led parts and create your own ledlamps maybe not 230VAC but 12VDC instead of throwing your money away gambling at Ebay

Yes, the ones designed to replace 12V halogens are good. Another option is to buy the bare diodes and build from scratch.

[Simon]

With a basic tool and same conditions you can at least make a comparison between two products

[dannyf]

they are a life threatening unsafe product and a possible fire hazzard

So true. 99% of what's sold on the bay is electronic junk.

For people to think about using them in critical applications, light mains lighting, it shows just how stupid humans can be.