Do Flashlights get dimmer with age?

MyUsernameTX

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I have some Fenix PD35's, the original versions that are 960 lumens. When I got them, they seemed SUPER bight, but now they just seem kinda meh

Have I got used to much brighter lights, or have these possibly gotten dimmer?

Not batteries, using brand new fresh 18650's
 

alpg88

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I feel the same about few of my lights, but no they do not get dimmer.
 

3_gun

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In a word .. maybe. Most / many LEDs claim 50000hrs to 1/2 of original output. What they don't say is how they get there, or at least I've never seen a statement / profile.

Is it 5 equal steps, each about 10000hrs long. Or is it logarithmic faster from peak & slower as light levels drop or slower from peak & faster as they drop. Given the nature of the lights, one would be more noticeable than the other. Or is it a sudden 50% drop at or near 50000hrs. Most likely you've noticed the older light looking "dimmer" today because of the massive improvement in output & CRI in todays new LEDs.

I use my lights more often & for longer runs than the average user & likely more than the average member of this board. It's normal for me to use my "work" light 6-20hrs a week & my "hobby" lights 4-6hrs per use. Even at these levels of use I doubt I'll get the hours in to get to a noticeable light output drop w/o a testing sphere
 

LRJ88

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In my experience it's not impossible, although i feel like that might be related to poor initial design where the LED is at the very upper range of power in and poor heat regulation to the point where it punishes the die. Although it might also just be the little nub on the die breaking down and soaking up some of the output.
 

PaladinNO

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This is actually an interesting question. How do flashlights tell their age? Do they just perform 100 % until they no longer work (at which point the user has to decide whether it's worth the money to replace whatever is broken, if possible)?

I got the original Fenix PD35 960 Lumen myself. Absolutely love it, but I found myself needing more than the 960 when I changed job (landed on the 3000 Lumen Acebeam EC50 Gen. 2 - which I recently sold, and replaced with a 10000 lumen Fenix LR35R).

The PD35 still works great, and I even have a second one brand new in the box, sitting on a shelf. I really didn't see myself replacing it, ever, when I bought them, considering I came from a Streamlight Twin-Task halogen -> Coast G45 -> Fenix PD35). ^^

Flashlights has to be one of the very few things I replace or upgrade, BEFORE whatever I own prior no longer works (I want to throw away as little as possible). A 3000 Lumen flashlight can simply shine brighter than a 1000 Lumen flashlight. And I find myself needing more than the 1000 Lumen, well, I buy an upgrade, and either sell or set the prior light aside for less demanding tasks.
 

MyUsernameTX

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The PD35 still works great, and I even have a second one brand new in the box, sitting on a shelf. I really didn't see myself replacing it, ever, when I bought them, considering I came from a Streamlight Twin-Task halogen -> Coast G45 -> Fenix PD35). ^^

Well crack it out and solve this one for us!
 

fredx

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I could not truthfully speak accurately about the lights-- But
for sure eyesight and judgement does
 
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iacchus

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In my experience it's not impossible, although i feel like that might be related to poor initial design where the LED is at the very upper range of power in and poor heat regulation to the point where it punishes the die. Although it might also just be the little nub on the die breaking down and soaking up some of the output.
This would be my guess as well. There were quite a few years during the chicom lumen wars were poor LEDs were being abused for specs. Those were never going to have the greatest lifespan.

There's also the matter of LED's getting better with advancing technology and our perceptual judgement changing. Our eyes have always been poor at detecting absolute brightness. Spec ratings have changed over time too.
 

aznsx

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A quick net search shows a lot on data on this out there on the web, the graphs I see appear to show a progressive (although not necessarily linear) reduction of output during service life, and the fact that there's a standard 'L70' rating for service life to 70% of rated output would seem to support that. I don't know myself, but this also sounds quite logical to me, so it is my 'working assumption' at this point.
 

MyUsernameTX

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This is actually an interesting question. How do flashlights tell their age? Do they just perform 100 % until they no longer work (at which point the user has to decide whether it's worth the money to replace whatever is broken, if possible)?

I got the original Fenix PD35 960 Lumen myself. Absolutely love it, but I found myself needing more than the 960 when I changed job (landed on the 3000 Lumen Acebeam EC50 Gen. 2 - which I recently sold, and replaced with a 10000 lumen Fenix LR35R).

The PD35 still works great, and I even have a second one brand new in the box, sitting on a shelf. I really didn't see myself replacing it, ever, when I bought them, considering I came from a Streamlight Twin-Task halogen -> Coast G45 -> Fenix PD35). ^^

Flashlights has to be one of the very few things I replace or upgrade, BEFORE whatever I own prior no longer works (I want to throw away as little as possible). A 3000 Lumen flashlight can simply shine brighter than a 1000 Lumen flashlight. And I find myself needing more than the 1000 Lumen, well, I buy an upgrade, and either sell or set the prior light aside for less demanding tasks.

What job do you do?
 

PaladinNO

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What job do you do?
At the time, it was an interiour carpenter. The storage warehouse, where all the kitchen tops and whatnot was stored, didn't have the best lighting, so I used the Coast G45, and later Fenix PD35, to easier read the labels. It was cute seeing my supervisor with his single AA Maglite to do the same thing.
I quit that job after 8 years because I was bored out of my mind.

I currently work with IT, and handle all the faulty hardware that is sent in to us for repair at a local school.
Definitely don't need a 10000 Lumen Fenix LR35R for that, but there is still the occasional trip down into the basement, where there is partly no light at all (because the building is mostly from the 1950's), and I want all the illumination I can get to not trip on the solid concrete floor.
 

letschat7

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Sometimes the bulb envelope will get tungsten deposits on it and will get dim. Time to replace the bulb.
Dang this is the led forum
This is like a Streamlight Scorpion Xenon seeming dim until you turn it on it a dark room in the middle of the night when you have been woke up and it as bright as can be but still only 70ish lumens.
 

Fresh Light

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I would expect the aging battery to be a much more significant factor in output. I have different new batteries, depending on model, that will give visually different outputs in high output lights. Are the new batteries being used as high current capable as the originals?
 

Ray_of_Light

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A Power LED lose 30% of the brightness after ~5000 thermal cycles.
One cycle is the thermal excursion of the LED - when installed on a heatsink - from 20 °C to 95 °C, and back.
Some LEDs are better than others, with Cree being among those with better lifetime...
Anthony
 
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