Last year I put up a string of golden-white LEDs at the side of my house and then decided I was going to leave them lit for a full year to see how their intensity had changed and if corrosion had been an issue.
I got two sets at the same time to keep one unused as a reference.
The corrosion result is interesting. Common DC strings are very prone to wicking in moisture and corroding, so I wanted to see if the cheap sets that reverse polarity to control two channels with just two wires had less of an issue with corrosion due to the alternating current being less likely to cause electrolytic damage than DC.
Note that in this video both strings were running on DC so only half the LEDs were lit. (They use alternating polarity to flash two sets of LEDs.)
Here's the video I mentioned that uses accelerated DC corrosion to create rusty water fast as part of a quack "detoxifying" treatment.
https://www.youtube.com/watch?v=zH0QpaDNwS8
Note the angry comments from people who give these very expensive and completely bogus treatments.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
I got two sets at the same time to keep one unused as a reference.
The corrosion result is interesting. Common DC strings are very prone to wicking in moisture and corroding, so I wanted to see if the cheap sets that reverse polarity to control two channels with just two wires had less of an issue with corrosion due to the alternating current being less likely to cause electrolytic damage than DC.
Note that in this video both strings were running on DC so only half the LEDs were lit. (They use alternating polarity to flash two sets of LEDs.)
Here's the video I mentioned that uses accelerated DC corrosion to create rusty water fast as part of a quack "detoxifying" treatment.
https://www.youtube.com/watch?v=zH0QpaDNwS8
Note the angry comments from people who give these very expensive and completely bogus treatments.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Now I am curious know how much they would lose in another year
Wow — didn't realize LEDs dim over time…now I wonder if the LED 3-way 150W light that I "feel" like is dim might ACTUALLY be dimmer and need replacement!
I hate the way current bulbs, be it CFLs or LEDs, gradually fade. You don't notice it on a day by day basis, but then one day you're thinking "it's kinda dark in here, isn't it?", change the bulb and realize you've been working for months under fractional amounts of light. It's annoyingly sneaky 🙁
I miss tungsten bulbs. They were either giving you full brightness, or zero brightness. Very simple. Also because they had a much nicer light spectrum 🙁
awesome };)
At our house, we've noticed this fall-off in brightness most on AC strings of multi-coloured Christmas lights, where the red and orange LEDs stay bright enough, but the blue ones fade away to nothing in two seasons.
We have not yet thought of a good use for strings of red and orange lights.
After watching this i decided to replace all my scattered 1w white leds i have all around the house with new 1w LEDs after running the LEDs for about 4 years!
I wish i had done it sooner! Every single chinese 1w cool white LED must have lost about 20 to 30% of their brightness after 4 years or so running!
I wouldn't have believed it if not for this video, thanks!
If you drive them at less intensity they last longer. I have to LED bulbs that are 9 years old that burn mostly 24/7 that have lost only a little brightness but they aren’t driven hard
Does the phosphors on gallium nitride leds degrade from just light intensity itself or is it because of the heat generated? In film production I use some white-light led sheets and strips that offer multiple led densities and the manufacturers seem to rate the lifespan of their more dense products dramatically less than the less dense more spread-out products presumably because of the extra heat created. I know that heat can cause the led's colour temperature to shift over time but I'm wondering if the intensity loss that you're referring to here with this type of white-light led means that the less dense products should theoretically lose intensity at the same rate as the more dense ones?
Thanks!
Are these Christmas white led's cheaper lower quality than standard white led's say from rapid electronics, cpc etc ?
When the LED Xmas lights came out a lot of folks did not like the very bright intensity of the leds. Also you could sort of tell the way it produced the light was nothing like the old filament type bulbs. To preserve the leds would be to have them on a PWM and DC circuit to control the brightness as well as providing a constant current. LEDs do not like too much current even at the rated current. I have a LED bank running on my bench now for 8 years been running on DC power and running at 80% of the rated current and it still produces the output like it was new.
Looks as though each string has several duds.
I want to run 100 strand of these wide angle LED mini string lights that came with a DC 3 AA battery pack on a 12v car battery in the garden shed that is on a solar panel. Would I just need to wire up some resistors on the positive end or would I need something else to slow the current?
I have seen this on several keyboards, the capslock led is much brighter than the numlock led.
Thanks for showing – very interesting! I am a bit surprised by the fast degradation of the leds after just one year. But its depending on so many parameters that it is hard to be generalized. On what current are the leds driven, how well does the PSU work, does it get overvoltage/current, do they get hot etc. etc. I build a night light a few years ago that is running 7/24 – and i cant see any degradation. I used SMD 5630 leds with nom. current of 45 mA. I run them on less than 1 mA (i thing it was around 0.15 mA) with sufficient brightness and they run of of two 18650 li-ion cells in parallel – i never charged them and starting voltage was at around 3.7V – now 3.6xx 🙂 The normal cell leakage is probably higher than the led consumption 🙂 It will probably last for the rest of my life (the leds)…