Do LEDs really last 10,000+ hours?

[Anemonebuff]

[QUOTE=Midnightsun;18512925]As mentioned, led life span really has to do with proper cooling and proper amperage feed (power). Heat is the led killer My thinking for longevity is to get a larger system than required and simply drive the led with reduced power to increase life substantially, reduce heat substantially, (my fan senses heat and turns on if required, has never come on yet) and possibly never need to change a power supply as it also is working very lightly.

QUOTE]

I have also found that most of the major LED systems under drive their LEDs to increase the life of the diodes. Under driving reduces heat produced, making it easier to cool properly.

[Midnightsun]

Originally Posted by atreis

I've been using CFLs in my house for 10 years now, and have found that on average they last about 5x the time that incandescents in the same fixtures lasted. There are exceptions - they last about the same in fully-enclosed un-vented fixtures as incandescents (the ballasts need to be able to cool), and every now and then I've gotten a bad batch (most of those seemed to be about three years ago). Likewise, I've had some last far longer than rated - I have a pair of CFLs rated for 8k hours that both have over 12k hours on them.

A year ago I installed my last CFL can light and started replacing them (as they go bad) with LED lights. I've only replaced two so far. Only time will tell. If they last as long as the makers claim (I'm using CREE bulbs rated for 50K hours, and these are replacing Ushio CCFL bulbs rated for 20K hours) I won't truly know for 20 years. For the non-can lights, I've not used all of my standard 60W replacement CFLs up yet, but also plan to stop buying those too and switch to LED.

I suspect you've not heard of many people doing this because: 1. It takes a long time assuming people do it as their current bulbs go bad, and 2. LED bulbs are expensive (the CREE can bulbs I'm buying cost $90 each). Even though they SHOULD pay for themselves in theory, the initial capital outlay is more than many people can stomach.

Interesting as I have replaced all my halogen Par 30 lights in the soffit of my house with the led variety also but went the "beehive" led style route for cost reasons as they were only $14 each. They are also rated 50,000 hrs and draw only 4 watts/bulb. The lighting is superb and the total string draws only 128 watts compared to 1600 watts before. Yes I have 32 lights outside. I have only been running them for a year but the warranty is 5 years. According to the supplier, 5 years constant on is 62,000 hrs. running normally about 5 hours/day I am supposed to be good for 1000 years. Regardless, energy consumption is way down there and if they last 10 years I will be more than happy.

[Anemonebuff]

I wish this place sold Reef Bulbs. They give a 5 year warranty. I have some of the 36 watt PAR38s.\

http://www.ledliquidatorsinc.com/PAR...light_bulb.php

[Midnightsun]

Originally Posted by Anemonebuff

I wish this place sold Reef Bulbs. They give a 5 year warranty. I have some of the 36 watt PAR38s.\

http://www.ledliquidatorsinc.com/PAR...light_bulb.php

That is exactly where I purchased all my bulbs for my house.

[nanojg]

So are the different versions the same LEDs just driven at different currents? (350, 700 and 1000 milliamps)

[Pink_n_Purple]

Originally Posted by Midnightsun

As mentioned, led life span really has to do with proper cooling and proper amperage feed (power). Heat is the led killer and again as mentioned, running led at reduced output (dimmed) will increase lifespan above manufacturers specs. In my case I have a powerhouse caddilac, the Vertex Illumina I run at max 50% during only a few hours a day and the balance is less as they are very slowly ramped up, held for a few hours and then very slowly ramped down. In this case if the manufactures claims 50,000 hrs I may last 20+ years.

My thinking for longevity is to get a larger system than required and simply drive the led with reduced power to increase life substantially, reduce heat substantially, (my fan senses heat and turns on if required, has never come on yet) and possibly never need to change a power supply as it also is working very lightly.

The most problematic part in led system is the power supply IMHO. In less than 3 months the power supply blew on my Maxspec. In about 7 months the power supply blew on my JBJ nano LED. Both of these systems run full bore and are not dimmable.

I agree, Midnight have u tried to make any attemps at keeping your power source cool? Also by running your leds on half power is it safe to asumme than you are not getting full effieciancy from your leds(need more leds to get your lumen/par/ppf/ppfd up?) more leds more heat back to square 1. cost/ effieciancy is reduced buy having more leds to creat same light out put?

Ijust dont believe that the average personne really will ever notice leds full potiential.

Yes your leds should last longer than 10,000 hrs.

[nanojg]

Actually the efficiency increases at lower current. The max lum/watt is at 350 milliamperes I believe, it decreases as you approach max current

[Midnightsun]

Originally Posted by Pink_n_Purple

I agree, Midnight have u tried to make any attemps at keeping your power source cool? Also by running your leds on half power is it safe to asumme than you are not getting full effieciancy from your leds(need more leds to get your lumen/par/ppf/ppfd up?) more leds more heat back to square 1. cost/ effieciancy is reduced buy having more leds to creat same light out put?

Ijust dont believe that the average personne really will ever notice leds full potiential.

Yes your leds should last longer than 10,000 hrs.

Like I said my led system is so powerful I can run it at half the required output and still be fine for any coral growth. That being said, running at half power reduces heat substantially which will add to longevity on all components. My previous attempts were maxspec and nano cube led which basically run full out all the time. Nothing wrong with this but design is critical and unfortunately most run on the edge which affects long term durability. To answer your question regarding efficiency, yes the output is reduced but I have twice the power required.

Compare it to running a car at very high speed all the time or running it at speed limit all the time. Which is going to last longer in the long run?

[ksc]

"The Federal Trade Commission announced on Wednesday that it had sued Lights of America, a light bulb manufacturer based in California, for misrepresenting the light output and life expectancy of its LED bulbs. It is the first F.T.C. case challenging LED marketing claims".


http://green.blogs.nytimes.com/2010/...ed-bulb-maker/

[Pink_n_Purple]

So inefect, you believe running your leds sub par of there disinged intended use will give you better results than what the manafacturer quotes this already being at optimal conditions? all where really aming for is 24 to 30 degrees for optimal temp not very hard to do considering it can be done to a 1000w hps. producing bairly any warmth to the touch ( the glass tube, not the bulb, great effects with the life span of Hort blues/super blues and others)

I will assume that you dont cool your powersource or havnt tried to, i would expect the same result from your newest controller, short life spans. Heat and humidity is a killer in any lighting system and most electronics.

you only lose the efficiency in the conversion of watt to lumen/heat ratio(i use lumen losely) Heat be the end result, producing to much heat in comparison to how much light. you cant expect to get the same kelvin ( kelvin used losely) temp from your diode by dimming them.

Prebuilt systems are really expensive, and even the more expensive ones will not last more than 10,000 hrs. Unfortunate to say the least. When they can run much much longer, at a even lower expense.
I'm sorry for maybe ruining your thread, new to the forum thing too.

[Shard]

Pink_n_Purple,

Again, welcome to the forum, but you are not understanding how LED systems work, or the physics of electricity involved.

Originally Posted by Pink_n_Purple

So inefect, you believe running your leds sub par of there disinged intended use will give you better results than what the manafacturer quotes this already being at optimal conditions?

Running LEDs at a lower temperature and/or lower current is not a 'sub par' condition or somehow outside of 'optimal conditions'. You could argue that the lower temp/current is MORE optimal for them.


As mentioned above, most LEDs are the most efficient at 350ma, which gives the highest lumen/energy output. The efficiency decreases as you approach max current. If you would take 5 minutes to read the datasheet you would see that 350ma is the 'sweet spot' for many LEDs like the Cree ones used in most fixtures today, but they run well at higher currents as well. Also, keeping the LEDs cooler allows them to run more efficiently (just like many other electronics). LEDs have an upper temperature limit, not really a lower one. I could run my LEDs at 0 deg C and they would run fine. That is not outside of their 'optimal conditions'.

Originally Posted by Pink_n_Purple

all where really aming for is 24 to 30 degrees for optimal temp

So many grammar and spelling errors, but anyway, no we are not. All we are aiming for is a temp BELOW the upper threshold, not really a tight range between 24 and 30. Again, you need to understand the difference here between an UPPER LIMIT for usage (LEDs), and a LIMITED RANGE (CFLs).

Originally Posted by Pink_n_Purple

I will assume that you dont cool your powersource or havnt tried to, i would expect the same result from your newest controller, short life spans. Heat and humidity is a killer in any lighting system and most electronics.

Again, you are making general speculations about something without consulting the datasheet. You do not need to actively cool a LED driver (power source) as long as you are running it within spec. Are you assuming that almost every LED driver used is being run improperly? You are basically assuming that everyone from the designing engineer to the home user is an idiot.

You mention humidity above as well in reference to drivers, so again see a datasheet, but lets assume you are talking about humidity exposure for LEDs themselves in a hood. Let me quote directly from the Cree datasheet (will provide link below).

"Moisture Sensitivity
In testing, Cree has found XLamp XP-G LEDs to have unlimited floor life in conditions ≤30oC / 85% relative humidity (RH). Moisture testing included a 168 hour soak at 85oC / 85% RH followed by 3 reflow cycles, with visual and electrical inspections at each stage."

Sounds like they are pretty darn resistant to me.

Originally Posted by Pink_n_Purple

you only lose the efficiency in the conversion of watt to lumen/heat ratio(i use lumen losely) Heat be the end result, producing to much heat in comparison to how much light. you cant expect to get the same kelvin ( kelvin used losely) temp from your diode by dimming them.

I don't really get what you are trying to say here, but I will give the link to the datasheet for Cree XP-G LEDs now.....

http://www.cree.com/products/pdf/xlampxp-g.pdf

Originally Posted by Pink_n_Purple

Prebuilt systems are really expensive, and even the more expensive ones will not last more than 10,000 hrs. Unfortunate to say the least. When they can run much much longer, at a even lower expense.
I'm sorry for maybe ruining your thread, new to the forum thing too.

Many LED systems now cost the same if not less than some similar MH setups. Even if they cost more, many can make up for the difference in less than a year, but I really don't feel like trying to show you what has been calculated many times already on this board. They won't last more than 10,000 hours? Where is your proof other than just your speculative opinion? Read the datasheet, yes they will last longer, or do you not believe in science?

Landon

[Pink_n_Purple]

[QUOTE=Shard;18515250] OMG i dont know how to multi quote!!!! this is confusing im sorry.

Again, welcome to the forum, but you are not understanding how LED systems work, or the physics of electricity involved.

Thank you, and no im not an electrical engineer nor do i own a spellchecker, or i cant find it.

Running LEDs at a lower temperature and/or lower current is not a 'sub par' condition or somehow outside of 'optimal conditions'. You could argue that the lower temp/current is MORE optimal for them.

Keeping abient temp and heat sink temps in check are very important to longivity of your led and power supply. Dimming your lights can help manage this, but it may alter the light wavelength. I believe the cost per lumen increases when operating at lower voltages. Initial setup costs are larger. More diodes, more drivers+dimmers more space taken up more potientiall issues may arise. Replacement costs also rise as a result. I'm interested, Can lenses be reused? i've never heard of this, honest question.


As mentioned above, most LEDs are the most efficient at 350ma, which gives the highest lumen/energy output. The efficiency decreases as you approach max current.

your right, but operating at higher ma should not effect there lifespan, if cooled properly.


If you would take 5 minutes to read the datasheet you would see that 350ma is the 'sweet spot' for many LEDs like the Cree ones used in most fixtures today, but they run well at higher currents as well. Also, keeping the LEDs cooler allows them to run more efficiently

Giving them there natoriously long life span of 30,000 hrs with little shift in color, something companies such as Cree and others state.

(just like many other electronics). LEDs have an upper temperature limit, not really a lower one. I could run my LEDs at 0 deg C and they would run fine. That is not outside of their 'optimal conditions'.

Most systems run at there upper limit, including most diy, even dimmed.
yes but my point is that heat creats a loss in voltage and can increase load on your power supply, requiring power supplies to work harder, and getting a short 1-2 year life span.


So many grammar and spelling errors, but anyway, no we are not. All we are aiming for is a temp BELOW the upper threshold, not really a tight range between 24 and 30.

Ambient air temp in and around you leds and power source have a direct effect on there effectiveness to "cool themselves" . most systems are inclosed and some r even further inclosed within there tank setup. Why r you aiming for the upper threshold when a lower temp is possible and not that inconvieniant, expensive or hard to do and would result in a longer life span.

Again, you need to understand the difference here between an UPPER LIMIT for usage (LEDs), and a LIMITED RANGE (CFLs).

Yes and as stated most run at there upper limit. Thats why most consumers start to see color shift or dimming after anly 15,000 hrs-20,000hrs @ best.


Again, you are making general speculations about something without consulting the datasheet. You do not need to actively cool a LED driver (power source) as long as you are running it within spec. Are you assuming that almost every LED driver used is being run improperly? You are basically assuming that everyone from the designing engineer to the home user is an idiot.

i'm making speculations upon reall world use. I should start a thread---"has your led system ran 20,000hrs without any noticable loss of light or burnt power supplies?" or "has you led system dimmed noticbly in the last year or two of opperation".

You mention humidity above as well in reference to drivers, so again see a datasheet, but lets assume you are talking about humidity exposure for LEDs themselves in a hood. Let me quote directly from the Cree datasheet (will provide link below).

poor soldering connections, exposed wire, also dry and cracked wire insulation was my worry. espicially when running wire close to or inside heat sinks.

"Moisture Sensitivity
In testing, Cree has found XLamp XP-G LEDs to have unlimited floor life in conditions ≤30oC / 85% relative humidity (RH). Moisture testing included a 168 hour soak at 85oC / 85% RH followed by 3 reflow cycles, with visual and electrical inspections at each stage."

Sounds like they are pretty darn resistant to me.

except that at higher ambient temps air can hold a much greater water volume, and temps are usually higher than 30oC around the diodes and power supplies. When the lights, and power source go out there can be a build up of condinsation as the air cools, if your power supply isnt 100% air tight or have exposed wire and is sitting in these conditions than there is a chance for this type damage to occur, which could result in unexpected failure, or loss of life expectancy. ie a controller lasting alittle longer than a year.



I don't really get what you are trying to say here, but I will give the link to the datasheet for Cree XP-G LEDs now.....

i believe what i was try'n to explain was that there is a limit at wich point the diode produces more heat than light and is deemed inefficient.


http://www.cree.com/products/pdf/xlampxp-g.pdf



Many LED systems now cost the same if not less than some similar MH setups. Even if they cost more, many can make up for the difference in less than a year, but I really don't feel like trying to show you what has been calculated many times already on this board. They won't last more than 10,000 hours? Where is your proof other than just your speculative opinion? Read the datasheet, yes they will last longer, or do you not believe in science?

Savings in hydro use r different from place to place for instance i only pay 5 cent a kwh when lights are on pretty cheap when compared to others so the savings vary, then add in unexpected failures and that savings may not be as great for some. ie me, cheap hydro.

No there not idiots thats why we spend our money on these systems and seem to be content with short life spans of our led's and controlers. I never stated that they wont last longer, quite the opposite. it just seems that the majority of users, in the reall world situations, wont ever really experience the FULL POTENTIAL of there led systems. Mainly due to improper heat managment, resulting in shorter life spans.

this last paragraph is what i originally wanted to get across.
Cheers!

[nanojg]

Uh... Is that post too long?

[Shard]

Originally Posted by Pink_n_Purple

OMG i dont know how to multi quote!!!! this is confusing im sorry.

You have to use a quote tag set for each section you want to quote. You cannot type anything yourself in between the quote tags.

For example the above looks like this to properly quote. {QUOTE=Pink_n_Purple;18516800}OMG i dont know how to multi quote!!!! this is confusing im sorry.{/quote}

You just have to replace the {s with [s.

Going to sleep as I have to dive early in the morning, will read over the whole thing later.

[ccLansman]

LEDs last as long as the best test run someone ever did under the best circumstances on the best day, of the best month, of the best year, ....ect ...ect ect... you get the point. The life expectancy is normally based off this type of data to make a product sound better. I really have not seen actual data to support the claim but i am assuming that is where it came from as most findings come from the same type of thing. OR if they are good about it, it will be the average life expectancy, meaning they tested say 1000, and half lasted that long, some more, some less.

[Anemonebuff]

Originally Posted by ccLansman

LEDs last as long as the best test run someone ever did under the best circumstances on the best day, of the best month, of the best year, ....ect ...ect ect... you get the point. The life expectancy is normally based off this type of data to make a product sound better. I really have not seen actual data to support the claim but i am assuming that is where it came from as most findings come from the same type of thing. OR if they are good about it, it will be the average life expectancy, meaning they tested say 1000, and half lasted that long, some more, some less.

So if they say 50,000 hours and they normally get 25,000 in real usage, if that were the case and not a made up number, wouldn't LEDs still be worth it?

[Reffer831]

Originally Posted by nanojg

No...

I was saying no to them lasting 10,000hrs

[Elysia]

Sorry, I've been away a bit... The LED fixture I have has both white and blue LEDs in the same housing. You have the option of having them both on or just the blues, but there is only one power supply. The white LEDs continue to work while the blue LEDs do not. The unit is (and has been) plugged into a timer that is plugged into a GFCI.

I understand that LEDs fail when they overheat -- I had AIO nanos with canopys that included compact fluorescents and lunar LEDs and of course those LEDs were toast in no time. But there is nothing heating this LED fixture... and why wouldn't all the LEDs in the fixture failure, instead of just half of them?

Most importantly, do I have reason to contact Marineland about this? I am disappointed and I can not think of anything that I did to cause this failure, but I thought I should check with those of you who know more about these things first, before I question the manufacturer.

[Ken Hahn]

There is some accurate and some pretty iffy LED info in this thread. Since I sometimes work with high powered LED technology in my industry (displays, not aquariums), I'd like to clarify a few points.

1. When the LED mfrs state a lifetime of 50,000 hours or so, that is a theoretical lifetime based on the known physics of LEDs. It is not a tested lifetime. Since it would take about 6 years to run that test, no one including the LED manufacturer has typically run one that long before initially releasing the part for sale. This estimated lifetime is generally considered to be pretty accurate under the ideal operating conditions that the lifetime is stated.

2. Achieving that rated lifetime in a light fixture requires that the lighting designers adhere to certain optimal junction temperatures of the LED die. These junction temperatures are not generally the same as the maximum junction temperature that is specified. A maximum junction temperature might be spec'd at 150C, but stated lifetime performance might be achieved at something under 100C. I saw one aquarium light mfr state that as long as the max 150C junction temperature wasn't exceeded the fixture would operate fine and that is simply not true. When you see a life rating on a light fixture, you can bet the manufacturer is just passing along the LED life rating from the LED mfr whether or not their fixture is operating those LEDs under the conditions needed to meet those lifetime specs.

3. High junction temperatures adversely affect LEDs short term for brightness and it tends to shift the color temperature of the light output. Lumen output of the LED are typically rated at some unrealistic junction temperature such as 25C, but will drop in brightness down to perhaps as much as 60% of that value as the junction temperature increases towards maximum.

4. High junction temperatures over time shorten the life of the LED, sometimes dramatically. Lowering the junction temperature, such as by running in dimming mode will lengthen the life of the LEDs - up to a point. For instance, I know one mfr that rates their super high power LEDs at 50,000 hours, but will increase their estimated life expectancy up to 80,000 hours as junction temperature is reduced but then they hit a theoretical limit as the LEDs tend to have other wear-out mechanism besides just the junction temperature. Obviously some mfrs of lighting might take the tact of hotrodding the LEDs to get the maximum brightness possible out of them as that is what the hobbyist wants to see, but that will directly lead to a shortened life.

5. Junction temperatures are a function of how much power is being put through the LED, generally in the form of current and how much heat is being extracted from the LED in the form of heatsinking. Low thermal resistance between the LED die and the heatsink is very important. Without cooling on the heatsink, you want it to get hot as a sign that it is pulling the heat away from the LED junctions, but when you apply the cooling to the heatsink, you want it to be adequate enough to significantly drop the temperature of the heatsink so that there is a good thermal gradient between the junction and the heatsink to help pull the heat away. A heat-soaked heatsink loses efficiency. If your heatsink is cooking, so are your LEDs probably.

6. I am sure that many lighting manufacturers pay little attention to the conditions that are necessary to achieve the maximum life and stability of the LEDs in their fixtures. To really characterize the junction temperature of an LED in a system is not a trivial exercise. It is very easy to build a fixture that turns a 50,000 hour LED into a 10,000 hour LED. It is also easy to design a fixture where failure of 1 LED increases the power through the other LEDs thus having an aging/failure ripple effect. You can also design the fixture so the bad (open) LED prevents the rest of the chain from operating.

7. As for LED ballasts and the like, all mfrs publish a maximum thermal spec. That thermal spec should not be construed that if it is set at 50C (for instance), that you are 100% fine running at 49C and going to instantly fail if you run at 51C. It is much more like a sliding scale with the closer you get to the upper range, the higher the failure rate will be. The upper temp spec is often gated by safety certification agencies like UL that care about burning stuff up and not about how long things last at different temperatures. Adding additional cooling to a particular unit that is running near the upper temp limit may not help, but you can pretty much be guaranteed that if a population of the devices are kept cooler rather than being run at their upper limit, the overall failure rate will be less over time. I like to think about it like the RPM redline in a car. While the car manufacturer says that you can run the motor up to 6000RPM safely, you know darn well that if you run around at 6000RPM all day, your car isn't going to last nearly as long as it would if you cruised around at 2000 RPM.

As one hard data point on LED life, we evaluated one well known high powered LED brand where we conducted measurements of stability over time measuring both brightness and color. In this case we were testing Red/Green/Blue LEDs and no white. At 10,000 hours we had measured less that a 1% drop in brightness and almost zero color shift using lab quality equipment. In fact the temperature fluctuations in the testing room had a bigger effect on brightness than time in this test. We were able to chart each time the air conditioning kicked on in the room. These devices were operating in a pulse mode of operation vs constant on, so this provides a more optimal junction temperature for best lifetime, but my point is that LEDs can be very stable over time given the right conditions.

I will also comment that white LEDs are typically phosphor converted blue LEDs. Phosphor has a similar thermally accelerated aging curve and some of the phosphors are bound with epoxy which can also yellow with age and temperature. I would expect that white LEDs would tend to be less well behaved over time in some regards for these reasons, though I don't have much long-term experience with them.

When you factor in not only all of the manufactures who in this industry vary from fairly large companies to garage shops, but also all of the DIY'ers that are randomly combining LEDs, heatsinks, fans and thermal paste into light fixtures, it is easy to image that the exact same LED might be lucky to last 5000 hours in one setup and be good for 25,000 hours in another. The desire to get the maximum brightness possible at the lowest cost possible in this hobby will probably always overrule achieving maximum lifetime because the first two affect the buying decision almost exclusively.

Yeesh, all of this writing just because I was doing a search on the Marineland LED fixture that I just saw down at the store to see if was any good.

[snorvich]

Excellent posting by Ken Hahn!