Author Topic: LED bulbs experience? Do they last as declared?  (Read 24020 times)

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Offline Hydrawerk

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Re: LED bulbs experience? Do they last as declared?
« Reply #75 on: April 23, 2017, 04:22:10 pm »
Any thoughts on Panasonic LDAHV11LH3?
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline macboy

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Re: LED bulbs experience? Do they last as declared?
« Reply #76 on: April 24, 2017, 02:13:52 pm »
The most common failure for any led system is driver failure usually due to electrolytic capacitor failure.   Cheap chinese 2000 hour 105C 50V caps are often use to hit a the low price point required for consumer bulbs.  Assuming the best case of 25V forward voltage,  the driver would need to operate at 78C to get the common 25k hour claim.  That is a hard temperature to reach when you are dissipating ~10W in such a small area. When you enclose the bulb, you can easily increase the operating temperature by 10C which would then reduce your life by half to 12.5k hours.

You shouldn't have to worry about the leds failing.  Even at high temperature 25k hours is easy to achieve with modern phosphors. 

In terms of CRI, all new leds are in warm white color temperatures have a CRI of at least 80 but the R9 value which renders red may only be single digits.  Recently 90+ CRI versions are becoming available due to pressure from California legislation. These will have a R9 value of at least 50, which will make skin tones look more like filament type bulbs. 98 CRI chips are available, but its debatable if it matters at that point.
I bought some ">90" CRI bulbs recently, and they are simply excellent. The difference in color rendering is immediately noticeable to me. Recently in Ontario, Canada there is a electric utility sponsored program where you can get huge discounts on LED bulbs, to encourage reduction in energy usage, as supply is a big issue here in summer. I was able to get $8 off packs of 4 bulbs that cost $12 (at Costco), so $1 each bulb after discount. They are the best LED bulbs I have bought yet, and the cheapest as well. Luminous brand. Roughly the same deal on PAR20, GU10 and filament style candelabra bulbs as well. I stocked up.

These were so cheap that I immediately took one apart to have a look. The driver in these has no electrolytic caps, just 3 film ones ... AC line to a series fuseable resistor, cap across the line for noise reduction, then a bridge rectifier going to two more film caps as a reservoir. A driver IC and a small amount of other SMD circutry rounds it out. I assume that the driver circuit is specifically designed to work with high ripple on the raw rectified DC. They have seven 1 Watt LEDs, probably in series and having two die each. The LED board lights brightly at around 50 VDC, drawing about 100 mA at that voltage. I like this driver board, it looks better than most of the ones I've seen doing post-mortem exams on dead CFL and LED bulbs in the past.

I was thrilled to finally replace seven incandescent PAR20 bulbs in my kitchen with these LEDs. The only issue is that they are so bright I needed to install a dimmer. Bulbs cost $7 total, dimmer about $45. Energy usage down from 210 W down to maybe 10 to 20 W (I dim them quite low). These are frequently used lights, so I should see savings soon enough.
 

Offline Dielectric

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Re: LED bulbs experience? Do they last as declared?
« Reply #77 on: April 24, 2017, 02:21:07 pm »
A while ago I bought a bunch of Feit warm white bulbs and almost all of them have failed. I don't think that more than maybe a quarter of them are still working. That's disappointing because the color temperature of them is nice, for an LED, warm white.

I don't like to make blanket statements, but I'll go for it in this case.  Feit is uniformly junk, every Feit bulb I've ever purchased (Menards mostly carries Feit) has died an early death, incandescent or LED.  Sometimes it's just the filament, sometimes it's stupid mechanical stuff like the glass coming loose from the base.
 

Offline rrinker

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Re: LED bulbs experience? Do they last as declared?
« Reply #78 on: April 24, 2017, 05:51:28 pm »
 When I really started seeing savings was when I replaced the 4x 150 watt floodlights for the back yard with LEDs. All four LEDs consume less power than just one of the old lamps, and they get used a lot - in winter it's pretty much always dark when someone is home so the lights are on whenever the dogs go out to do their business. In summer, we spend a lot of time outdoors and in the pool. 
 My electric bill always shows a graph comparing current use with the same period the previous year, for the past 12 months. It is consistently lower and that's SINCE adding my electronics workbench. In the process I replaced one old computer with 2 of the latest low energy types with highly efficient power supplies. They aren't that removed from one another that the two new ones use less electricity than the one older one, but there has been no increase in utilization on the scale of the bill. I know buying the robot cleaner for the pool helped over the summer - it doesn't use nearly as much power as the 2 1/2 HP filter pump, but running the robot daily allowed me to reduce the time I had the filter run. That doesn't affect winter though, that's all the LEDs - it was actually colder this winter than last winter, my gas usage was up because the furnace ran more but that means the electric circulating pumps (I have 3 zones) ran more as well. Still less electricity used than same period last year.
 

Offline Red Squirrel

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Re: LED bulbs experience? Do they last as declared?
« Reply #79 on: April 24, 2017, 10:47:41 pm »
In theory CFLs and LEDs should last a long time, but normally they cheap out on the driver.

There is a lot of hate for CFLs but I have to say I have them throughout most of my house and they have lasted a long time.  I've had the odd ball go bad but a good part of them have been in use since I moved in a bit less than 10 years ago.

Back then the only LEDs you could get were spot lights and they were like 30 bucks a pop.  Now they make LEDs that are unidirectional like regular bulbs and they arn't that expensive so as the CFLs die I'll probably go LED.

For LED you really need to buy locally from a real store though. The stuff you get on Amazon comes straight from China with no UL rating and is going to burn your house down.  Some of them even have exposed mains.    That goes with a lot of stuff though, even phone chargers.  Lot of them arn't even mains isolated. So it's 5v out between the two pins, but it will be mains referenced and around 120v from pin to ground. 
 

Offline madires

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Re: LED bulbs experience? Do they last as declared?
« Reply #80 on: April 25, 2017, 10:05:11 am »
My parents started using CFLs about 20 years ago and a few CFLs survived until today. But they also had several more modern types which failed quite soon (mostly OSRAM). Buying brands isn't a safe bet. A lot of the LED bulbs in local shops are imported from China. A typical cheapie is €2 or €2.50 (equivalent to 60W incandescent). The better ones are about twice the price. I've skipped the CFLs and went LED directly.
 

Offline kaz911

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Re: LED bulbs experience? Do they last as declared?
« Reply #81 on: April 25, 2017, 07:02:55 pm »
My parents started using CFLs about 20 years ago and a few CFLs survived until today. But they also had several more modern types which failed quite soon (mostly OSRAM). Buying brands isn't a safe bet. A lot of the LED bulbs in local shops are imported from China. A typical cheapie is €2 or €2.50 (equivalent to 60W incandescent). The better ones are about twice the price. I've skipped the CFLs and went LED directly.

Most of the CFLs I have replaced have been due to some sort of "mechanical" failure. Either plastic becomes brittle or glass somehow breaks. And then they become a PITA to exchange in many lamp designs - wear gloves. I think 50% shatters when you try to get them out if they have been in there for 5-10 years. Usually no matter how careful the glass will rupture.
 

Offline helius

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Re: LED bulbs experience? Do they last as declared?
« Reply #82 on: April 25, 2017, 07:08:49 pm »
You can prevent bulbs getting stuck in the socket after many years by applying dielectric grease when installing them.
One thing that I don't like about CFLs is their extended height compared to the incandescent bulbs they replace. It makes them fit poorly in table lamps and ceiling fixtures, and I even hit one with a door by not paying attention :(
 

Offline james_s

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Re: LED bulbs experience? Do they last as declared?
« Reply #83 on: April 25, 2017, 07:10:44 pm »
I've never had a CFL fail of mechanical issues, usually what happens if they last a reasonable life is the cathodes wear out, run hot and melt the plastic before eventually cracking the glass to metal seal which extinguishes the lamp but I still haven't had one actually break. Usually I had ballast failures, especially in lamps that were cycled frequently.

LEDs are so much better that I've long since retired all of my CFLs and replaced with LED. Mine are almost all a mix of Philips and Cree, both have been excellent. I've had a grand total of one LED bulb failure since I installed them in 2011 and that was a cheap EcoSmart branded bulb that I used in an enclosed fixture despite the warning not to.

I never had much luck with Feit bulbs myself but a friend of mine has a bunch of the early Feit LED bulbs that Costco was selling and his have all been fine, I've actually been really surprised they've held up. I think the earlier LED bulbs were over-engineered because manufactures knew that they had to live up to the claims in order for people to buy the expensive bulbs after so many CFLs failed to last as long as they were supposed to. I had some CFLs that didn't even last as long as incandescent but at least they didn't fail with a bright flash and pop that could make one nearly pee themselves when walking into a dark room and flipping on the light. That's one aspect of incandescent lamps I really don't miss one bit.
 

Offline kaz911

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Re: LED bulbs experience? Do they last as declared?
« Reply #84 on: April 25, 2017, 07:18:38 pm »
You can prevent bulbs getting stuck in the socket after many years by applying dielectric grease when installing them.
One thing that I don't like about CFLs is their extended height compared to the incandescent bulbs they replace. It makes them fit poorly in table lamps and ceiling fixtures, and I even hit one with a door by not paying attention :(

I always do for outside.:) but none was of my installation :)

I do a lot of marine stuff and have my magic special grease with me everywhere. Like very thick honey when cold - but heat it a bit and you can paint/dip things that need protection. Works wonders. Power bus bars and battery contacts in boats are often the first place to look for trouble - so they get a good thick layer - and never ever any issues there again. I coated parts on a boat once - where the owner forgot to enable the bilge pump. Water rose up over the bus-bar before he noticed. I drained it - and no issues. But engine oil pan needed replacing within 6 months. That was UAE where the water is so salty things start rusting in about a day if left outside. But busbar is still perfect. :) now 5 years later.
 

Offline james_s

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Re: LED bulbs experience? Do they last as declared?
« Reply #85 on: April 25, 2017, 07:29:32 pm »
Modern CFLs and LEDs are no bigger than standard incandescent lamps, at least the ones I've had. Philips, Cree, GE probably others make LED bulbs that are exactly the same size and shape as a standard A19 incandescent.
 


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