Longlevity of LED bulbs not so long

[bankruatsteve]

23 minutes ago, unblocktheplanet said:

Remember the promise of saving the planet through cheap, cool lighting for the future? 18 years per bulb!

 

Of course, 18 years had not elapsed. Give me a B25 incandescent any day. Far better light, more gentle on the eyes.

 

And do the experient I did, light a house plant with LED... Just saying.

Hey some folks prefer horse and buggy, up to you.  I have googled lighting for plants in the past and the normal LED is ineffective (they do make special for plants though).  CFL is the best for plants.

[Fruit Trader]

31 minutes ago, unblocktheplanet said:

And do the experient I did, light a house plant with LED... Just saying.

I do and the plants love it.

[HHTel]

1 hour ago, mike324 said:

branded ones have a warranty of couple months I believe, I buy mine from homepro and always gets it exchange if it fails within the warranty period, easy to exchange and no questions ask, just have to keep the box and receipt.

 

Majority of them have lasted over 2 years so far, they seem to last longer than conventional bulbs for me.

Homepro actually guarantee their LED bulbs for a year presently.  Providing you've kept the receipt of course!!

[tebee]

About 5 years ago I ordered some very cheap (20 baht) 3 w led BC bulbs from ebay. I have two of them that have run 24/7 365 day a year since then . One is near my front door so I can go out and come back at night without having to leave a light on, the other is near the bottom of my stairs so I  don't have to put other lights on when I'm half asleep in the middle of the night and go downstairs to the toilet - which I have to do far too much these days, thanks to a dicky prostate.

 

I thought about putting them on a timer, but discovered the timers I had take 7 watts to run, so it's cheaper just to leave them on. Works out at about 100 baht a year. I'm also away quite a lot so I regards them as a small security deterrent. 

 

I reckon they've done about 25,000 hours so far. I'm pleasantly surprised as they were both cheap and fairly early LEDS - so sometimes cheap bulbs do last ! 

[RocketDog]

On 6/23/2019 at 7:56 PM, mahjongguy said:

I have a range of brands and wattages of LEDS in the house and I am satisfied with them. But, there are five bulbs outside and none of them are long lasting. Sure, they're on for twelve hours a day but that's no excuse for burning out in four months. All of them are in enclosures and they all get extensive exposure to the sun. They seem to fail during the day when they're not in use, so it seems to me that they can't take the heat. 

All semiconductors are inherently long-lived except for one issue: heat.

They all degrade rapidly at high temperatures, so their individual efficiency is supremely important. That is, how much of the energy they consume ends up dissipated as heat. Second is how well the heat is dissipated away from the device, keeping its junction temperature low.

LED devices are notoriously inefficient though better than incandescents. So devices that use a lot of metal to dissipate the heat from the LED die have longer life.

 

Copper is the most reasonable metal to use for this, but cheap devices shun it to make it a cheap device! For the same reason most electrical wiring in Asia as well as outlets, switches, plugs, etc. doesn't use the tradional copper or bronze, but instead is made of nickel-plated steel. The higher resistance of steel leads to heat dissipation which again leads to short product life. This manifests as melted plugs and hot outlet strips that quickly rust, making the resistance higher, and the death spiral continues. High quality electrical devices use copper exclusively.

 

Expensive LED devices last longer because  they have good heatsinks.

 

That's the whole story right there.

 

Unfortunately an expensive price doesn't mean it's not cheap junk. Buy global brand names and skip the Chinese junk if you can even find some.

[Beggar]

On 6/23/2019 at 8:00 PM, BritManToo said:

LED bulbs you can pull apart and repair.

They are fairly simple, and the failed part is usually obvious.

Keep the broken ones, and cobble together new ones from the good parts.

Great idea. Can you help me? 

 

One of many dead ones. Mounted open and hardly used. LED scrap. Should have worked 30.000 hours... 

[tjo o tjim]

Usually the power supply dies. Does the emitter board have any text on the back— rated current and voltage?

[sometimewoodworker]

46 minutes ago, Beggar said:

Great idea. Can you help me? 

 

One of many dead ones. Mounted open and hardly used. LED scrap. Should have worked 30.000 hours... 

 

In the one you show there are 3 chips with at least 1 led that has failed, one of them probably has at least 2LEDs that failed, probably the PSU is OK.

 

 

Depending on your level of skill and tools you have it will be good practice to try de soldering those. You could also try testing to see if they show open circuit, though the other LEDs may interfere with that. With the de soldering you may have to heat the aluminium backplate, if you do manage to de solder them you will absolutely have to heat the backplate when you put replacement chips on it as otherwise the temperature of your iron will have to be so high

that you will cook the new chips or have dry joints.

[sometimewoodworker]

9 minutes ago, tjo o tjim said:

Usually the power supply dies. Does the emitter board have any text on the back— rated current and voltage?

No it doesn't, in this case there are 3 chips with dead LEDs. This a far more common failure mode for these lights.

[Beggar]

2 minutes ago, sometimewoodworker said:

In the one you show there are 3 chips with at least 1 led that has failed, one of them probably has at least 2LEDs that failed, probably the PSU is OK.

 

 

Depending on your level of skill and tools you have it will be good practice to try de soldering those. You could also try testing to see if they show open circuit, though the other LEDs may interfere with that. With the de soldering you may have to heat the aluminium backplate, if you do manage to de solder them you will absolutely have to heat the backplate when you put replacement chips on it as otherwise the temperature of your iron will have to be so high

that you will cook the new chips or have dry joints.

You are really an expert. How much do you charge for the repair? Just kidding. 

 

Could kick myself in the ass. Just discovered that I have (had now... ) a warranty of 1 year. This is how I waste my money... 

[sometimewoodworker]

5 hours ago, Beggar said:

You are really an expert. How much do you charge for the repair? Just kidding. 

 

Could kick myself in the ass. Just discovered that I have (had now... ) a warranty of 1 year. This is how I waste my money... 

Not really an expert, I just have enough knowledge to play one here.

 

Crossy is one of the real ones here, there are a few others as well.

 

I haven't tried to de soldier surface mount chips as I've got enough projects that need doing and it's not cost effective to bother.

[Beggar]

17 minutes ago, sometimewoodworker said:

Not really an expert, I just have enough knowledge to play one here.

 

Crossy is one of the real ones here, there are a few others as well.

 

I haven't tried to de soldier surface mount chips as I've got enough projects that need doing and it's not cost effective to bother.

Too bad that you don't live in Pattaya... ????