The myth that LED lights last forever

[oreo54]

The canopy of my next reef tank.

Tank with candle holders

 

[Tavero]

Tank with candle holders

Lol.
These are highly likely flower pots. They had to hide their hardware and tubing somehow

 

[oreo54]

Lol.
These are highly likely flower pots. They had to hide their hardware and tubing somehow

Actually mine has both..
Candle and plant stands..

https://joanbogart.com/vintage-fish-tanks

She could be wrong but certainly could be "repurposed" for our modern candle lights..

 

[oreo54]

For fun

 

[buruskeee]

I have HUE lights all through my house and when they automatically turn on I have them set to blues and purples and my coral react to those lights 100%.

What lighting technology are the HUE bulbs?

I foresee irony in the near future.

 

[alton]

I found this PAR lamp on Amazon. Waiting to see how long it last on my refugium/sump. The coral in the back started as a 1" disc dropped by a Welsophyllia. It has grown outward, just waiting for it to grow upward. Friend gave me the torch.

 

[Dburr1014]

I found this PAR lamp on Amazon. Waiting to see how long it last on my refugium/sump. The coral in the back started as a 1" disc dropped by a Welsophyllia. It has grown outward, just waiting for it to grow upward. Friend gave me the torch.

Is it this one?
I did some numbers on it.
It actually grows coral quite well. My frags of purple Stylo directly under the light are really a bright purple.

 

[Ef4life]

Is it this one?
I did some numbers on it.
It actually grows coral quite well. My frags of purple Stylo directly under the light are really a bright purple.

Pretty cool to see these again, these style lights were big on nanos back in the day before all the store bought nano light options.

 

[alton]

That is the exact one

 

[MnFish1]

Gotta love those old aquariums .

Jewel Aquarium Co. Bronze Seahorse, Dolphin & Clam Aquarium

Jewel Aquarium Co.-Chicago, circa 1920 Figural aquarium with decorative seahorse legs, four dolphin tails terminating with clam shell sconces/nautilus lights, all in solid bronze. The stretcher frame and table frame are wrought iron. Glass walls and white porcelain base.

www.chairish.com

Rare Fiske Aquarium on Stand Signed and Dated at 1stDibs | antique aquarium stand, vintage aquarium stand, vintage fish tank stand

View this item and discover similar for sale at 1stDibs - In two parts, this very rare piece is exceptional in all respects. All original paint; perfect condition; exuberant acanthus leaf decoration to the stand;

www.1stdibs.com

The tank (seemingly??) has been reinforced with a new tank inside - probably custom - there is obvious silicone (not available during this time. For sure a cool thing

 

[MnFish1]

See @Daniel@R2R - you were about to end the thread - and look at the positive information

 

[Daniel@R2R]

See @Daniel@R2R - you were about to end the thread - and look at the positive information

I wasn't ending...just enjoying the opportunity to give input. #candlesruleall

 

[oreo54]

That is the exact one

As a side note.. not too long ago lights like this had a very poor track record as to longevity. Not the diodes but all the electronics behind them that gets cooked by the heat. I'd consider them disposable until proven otherwise.

Pretend its a mh bulb.. sorry couldn't resist.

 

[Tavero]

As a side note.. not too long ago lights like this had a very poor track record as to longevity. Not the diodes but all the electronics behind them that gets cooked by the heat. I'd consider them disposable until proven otherwise.

Pretend its a mh bulb.. sorry couldn't resist.

That's the cooling issue I mentioned. If the heatsink is any hotter than "still comfortable to touch" it's too hot for the diodes and electronics.

 

[Mark Gray]

Many enthusiasts have long favored LEDs over T5s, citing the belief that while T5 bulbs require annual replacement, LEDs will remain robust for over a decade. But where did this enduring myth about the infinite lifespan of LEDs originate?

Prominent manufacturers such as Kessil highlight a life expectancy of 35,000 hours for their lights, which translates to around 5-7 years for the average user. Similarly, Philips' coral care lights advertise 25,000 hours at full light output, amounting to just 2.5 years or up to 5 years if operated for 12 hours daily.

Considering the quality reputation of these brands, one might infer that other less renowned brands might offer even shorter lifespans. A notable observation from a forum memeber mentioned that the Red Sea ReefLed 90, which originally emitted 800 par directly underneath when new, declined to 600 par after just two years.

Moreover, there have been accounts of hobbyists who, upon integrating a second identical LED unit, observed noticeable discrepancies in brightness even with identical settings.

This evidence suggests that LEDs, akin to traditional bulbs, experience degradation over time, with shifts in spectral output mirroring that of bulbs and tubes. Contrary to popular belief, studies by BRS have shown that T5 tubes can function effectively for more than 18 months before requiring replacement. Furthermore, they offer superior light spread compared to other sources. This accentuates the argument that LED fixtures dont really provide value for their cost. If one were to compare, they'd only need three sets of T5 bulb replacements over the lifespan of an average LED fixture and would likely achieve superior results, especially with specific corals like sps.

My thoughts on this is probably mostly due to the LEDs boards and power supplies are diminishing due to heat. Fans cool a little but probably not enough. The one thing at least in my home the house stays far cooler in the summer with LEDs. But thinking about this heat I might try to get a new set and figure out a good way to cool them maybe a CPU cooler.

 

[BeanAnimal]

That's the cooling issue I mentioned. If the heatsink is any hotter than "still comfortable to touch" it's too hot for the diodes and electronics.

I don’t agree with that assessment.

 

[BeanAnimal]

That's the cooling issue I mentioned. If the heatsink is any hotter than "still comfortable to touch" it's too hot for the diodes and electronics.

I guess I should elaborate:

Pain threshold in the average human hand is around 110° F for reasonably short contact.
It is recognized that prolonged contact (25 or more minutes) at 109° F can cause skin damage (burns).

The common "safe" recognized 5 second touch temperature (hand), where permanent damage does not occur to skin is 140°. Note that contact longer than 5 seconds can (will) cause damage.


Different LEDs will have different recommended safe and maximum junction temperatures, but most max out at 150° C (302° F). Most manufacturers recommend driving thermal management to keep junction temperatures between 60° C and 80° C. That is 140° F to 175° F - way too hot to touch. Assume that most reasonable designs will hit 75° C at 100% output.

It is easy to understand why a heatsink may be effective at maintaining that junction temperature, but still be too hot to touch.

If you want to get into the math, feel free (I have absolutely no desire)

https://downloads.cree-led.com/files/da/x/XLamp-Thermal-Management.pdf

Also in reference to this thread ... If anybody wants to check out CREE data on L80, L90, etc lifetimes vs junction temperature for ANY of their chips...

https://downloads.cree-led.com/files/da/x/LM-80_Results.pdf

Other OEMS will have similar data and results.

Sure looks to me like you can drive the snot out of most of them to 105° C and still get 41K hours (over 11 years) before crossing the L90 threshold. So now consider that you are not not likely running your fixture at a junction temp of 105° C for 10 hours a day... Drop that to 75° C and you get 45K hours, etc.

But but but... Tullio said...

 

[Epic Aquaculture]

All I can say is that using interweb influencers as experts eliminates any chance of me taking someone seriously. Also the Original Post was garbage and nothing but click bait type of posting... That's an hour of my life that I'll never get back.

 

[Tavero]

I guess I should elaborate:

Pain threshold in the average human hand is around 110° F for reasonably short contact.
It is recognized that prolonged contact (25 or more minutes) at 109° F can cause skin damage (burns).

The common "safe" recognized 5 second touch temperature (hand), where permanent damage does not occur to skin is 140°. Note that contact longer than 5 seconds can (will) cause damage.


Different LEDs will have different recommended safe and maximum junction temperatures, but most max out at 150° C (302° F). Most manufacturers recommend driving thermal management to keep junction temperatures between 60° C and 80° C. That is 140° F to 175° F - way too hot to touch. Assume that most reasonable designs will hit 75° C at 100% output.

It is easy to understand why a heatsink may be effective at maintaining that junction temperature, but still be too hot to touch.

If you want to get into the math, feel free (I have absolutely no desire)

https://downloads.cree-led.com/files/da/x/XLamp-Thermal-Management.pdf

Also in reference to this thread ... If anybody wants to check out CREE data on L80, L90, etc lifetimes vs junction temperature for ANY of their chips...

https://downloads.cree-led.com/files/da/x/LM-80_Results.pdf

Other OEMS will have similar data and results.

Sure looks to me like you can drive the snot out of most of them to 105° C and still get 41K hours (over 11 years) before crossing the L90 threshold. So now consider that you are not not likely running your fixture at a junction temp of 105° C for 10 hours a day... Drop that to 75° C and you get 45K hours, etc.

But but but... Tullio said...

Well then. I didn't include units because some americans get angry seeing metric. But you allowed it

Comfortable warm means ~45°C for me. Touching such a heatsink won't feel uncomfortable for anyone I hope. Anything hotter than 50°C though is actually too hot already for aluminum heatsinks, because silica diodes need to transfer heat through several bottlenecks. First from silica die to copper circuitboard. Then thermal paste/glue. Then finally aluminum heatsink. That's why a diode on a 60°C heatsink could already reach toasty 100°C in worst cases.

Manufacturer datasheets don't really recommend any temperature. They just guarantee a certain minimal lifespan for a max temperature. One Example: For standard Elkos that's 2500h at 85°C
ambient temperature because they don't produce heat on their own.
LED diodes do. The 105°C from your Datasheet is measured directly from the silica. Not copper heatspreader nor heatsink. They are much colder. The Silica in lot of lights is probably reaching over 130°C which destroys them prematurely, while their heatsinks are just hot to the touch.

 

[Shon]

americans get angry seeing metric. But you allowed it

Comfortable warm means hot tub for me. Touching such a heatsink won't feel uncomfortable for anyone I hope. Anything hotter than medium rare steak though is actually too hot already for aluminum heatsinks,

My preferred American measurement

Edit: my old hot tub had a safety cut off at 113f, I cook m-rare in sous vide 128f. As an American, I can honestly say we measure things with comparisons quite often.