View Full Version : Do LED's Fade?

Jim Warfield
11-22-2008, 11:37 PM
I recently replaced two Exit signs . Both of them were dim and acted as if they had simply faded?
I checked the voltage supplied, it was 120, not the cause.
These signs had been so bright that they lit up the areas of the house they were located in.
Once when power to the whole house was lost was when they went dim and never revived themselves!?
They might have only been in use for as little as 3 years when they dimmed themselves?
I am hesitant to purchace such lighting if it doesn't last.
Do they fade?

11-23-2008, 06:54 AM
I have an LED flashlight that has been dropped one too many times and occasionally it will "fade". Give it a good rap on something and it comes back so it is just a loose connection internally. Maybe you have a cold solder joint somewhere in it. If you can get to the driver circuit I would suggest reheating each of the connections.

Jim Warfield
11-24-2008, 09:22 AM
I could re-heat some of my connections!
"L" "ED"?
So heat works instead of Viagra? Sounds basic and good.

11-24-2008, 05:24 PM
I saw in the Gainesville Sun a story about Chirstmas LEDs, they said that LEDs don't burn out but will fade after about 50,000 hours of use. I have no idea if this is true but how long have you had those exit signs on.lol,

11-24-2008, 07:28 PM

My favorite tool is a hammer so Iíd side with Barry and hit it with a BFH if that does not work try duct tape any second fav.

Three years is only a little over 26k hours but maybe they were driving them hotter then normal. My first thought was if it was an exit sign with emergency battery back up and your power went out maybe the rechargeable batteries lost a cell or shorted a bit and caused an additional drain on the power supply. But you say there are two different signs? Odds both having batt problems at the same time are slim but you could pull the batteries and see.

Jim Warfield
11-24-2008, 07:41 PM
I assume the batteries only work when the 120volts fail, don't they? So logically they should be bright using just the 120 volts? Shouldn't it?
Maybe the Zinc Oxide (baby powder) gets out of position and shaking it puts the powder back where it works better?
Removing Exit signs to shake them every three years sounds like stupid work to me.

11-24-2008, 08:53 PM
Is it a etch a sketch exit sign? lol

I assume the batteries only work when the 120volts fail, don't they? So logically they should be bright using just the 120 volts? Shouldn't it?

Right, but when the 120vac is on, there should be a power supply that takes the voltage down to something like 12 volts DC that charges the batteries and this low voltage should supply power to the LEDís also. If the battery is pulling down the power supply when charging, the power to the LEDís would be low also.

Jim Warfield
11-24-2008, 10:19 PM
I guess that I'll disconnect the batteries and plug in the 120 voltss then?
Both signs had dead batteries.
We lost power in this part of town for 3 1/2 hours once one year.
For the first 90 minutes my house was all lit up compared to everyone else's place since I have battery emergency lighting in every room. (Gee, sort of like that one Twigh Light Zone show where everyone's lights quit except for one guy's , so they all thought he nust be the Martian...."
One night a car load were lost, we were on the phone with them numerous times guiding them here.
As they turned the last corner at Charlie's Tavern with the house in sight for the first time all the lights in town went off!
Really scary for them! Sort of like a "Gotcha!"on a grander scale though.
Some people have asked me before if I controlled all the electricity in this part of the town?
Sure, wanna see the BIG breaker I have in the basement?
Some others would arrive here late at night and the town is pretty empty and they would ask me at the end of their tour if I owned the whole town?
It would make a nice movie set for an 1880 downtown.
Sure I own it all, next week we start putting the glass dome over it all, a haunted theme park!
A dome about 400 foot across would pretty much cover it all. Maybe 500?

Jim Warfield
11-24-2008, 11:18 PM
I pulled out the dead battery, re-wired up the 120 volts still had a very dim LED light situation.
They are maybe as bright as one candle, maybe not even.....put the lense over it and it becomes almost nothing.
The dead battery was made in France?
First French made battery I think I have ever seen.

11-25-2008, 02:35 AM
Were the French batteries smoking (cigarettes)?

Strange that it started after you lost power and happened to two at the same time. Sorry that didnít work. Iíve had stuff with LEDís on for countless years but only the last couple of years Iíve started to use the super bright ones.

Since your house is haunted, that would be my next diagnosis. Bet you could sell them on eBay for big bucks! HAUNTED Exit Signs!!!

Jim Warfield
11-25-2008, 02:44 AM
Their replacement Exit signs light up a good portion of the room that they are each in, a real night lights just the way they should be to worth installing.
The tired ones could have been replaced by a jar of lightning bugs, about two bugs would have equaled the output.
...so if the house burned down everyone would be hearing the screams of those two bugs, "Save us! We promise to try to be brighter next time, give us another chance!"
Then we find their tiny little cigerettes and lighters.....which were not U.L. approved!