led gu10 lamps - do they fade over time??

[kilrail]

I am a big fan of energy saving and have been installing led downlighters gu10s to replace my 50 watt halogens. It has worked well in the hall and study and downstairs cloaks but I realised that it might not be bright enough for the kitchen diner.
However, some 72 led bulbs (3W) came on the market and when I first put them in I was quite impressed (not as bright as halogen but acceptable).

Then I thought they seemed to be getting dimmer but couldn't be sure. Much to wife's annoyance (she hates me buying gadgets) I bought a light meter and I could see that the 72 led bulbs were giving out less light that the 48 leds (all from the same supplier). I contacted him and I sent 2 back and he agreed faulty and sent me 6 replacements. Out came the trusty light meter and sure enough back to full strength and it was obvious as well.

However, after 4 weeks I thought they were not looking as bright although my wife disagreed, and yes, you've guessed, I used my light meter and they had reduced in brightness by 25%.
Now my question is "Has anyone else experienced this or is there some electrical supply issue or should I just give up and go back to halogen in the kitchen?"

I don't want to bother the supplier again (from Hong Kong) but he does seem very reliable and the all the previous bulbs are as bright as ever, although they all had fewer leds (24, 30 and 48)

 

[Cremeegg]

I've been using many 3W LED's in downlighters for an increasing number of clients. A single Luxeon LED rated at 3W. The manufacturers do give a figure for performance drop off - can't remember it off hand but its quoted after something like 10,000 and 20,000 hours for a lamp that they will quote a 35,000 to 55,000 hour life on. Will have a look around and post the details if I find them.

 

[breezer]

cheap leds

 

[aptsys]

The ones with multiple 5mm leds are ****e. The type Creameegg fit are much better (You can also get 5, 10 and 15W versions with Edison-Opto emitters) and will not deteriorate anywhere near as quickly unless they are overheating from lack of ventilation.