milkyspit
Flashlight Enthusiast
Had an interesting experience tonight.
My favorite small light is a lambda-modded E1E with copper pill. Great walking light! Low dome LED, yet packs a wallop in total output, and even in distance for such a small light! /ubbthreads/images/graemlins/bowdown.gif
Lately the light would intermittently start flickering, even with a fresh battery. I briefly suspected the LED was blown, but that wouldn't make much sense, as this thing is VERY well heatsinked. Then I started thinking about how contact was made with the E1E body. The positive connection is the usual raised solder ball touching the top of the cell, so no surprise there. A visual inspection suggested it was in good shape.
The negative contact point, apparently, is a little more precarious. The ENTIRE outside of the copper slug is negative, but it appears that only a narrow lip presses against the top of the E1E battery tube. Also, the copper was tarnished, though not horribly.
Finally I couldn't take anymore. /ubbthreads/images/graemlins/grin.gif
Got out some copper cleaner, took the slug out of the light, and veeeery gently rubbed a little copper cleaner into the copper along the sides, taking care not to wet top or bottom. (In reality getting wet probably wouldn't have mattered, as both top and bottom are epoxied solid.)
Then I "rinsed" by wetting the corner of a sponge and running it along the side, and driec thoroughly with paper towels.
Put it back in the light, and voila! The problem is seemingly gone, at least based on the limited runtime I gave it. /ubbthreads/images/graemlins/cool.gif
Here's what I suspect happened: the tarnish introduced a resistance just high enough to drop the cell's voltage below the threshold for the converter in the pill. I suspect that lambda chose a cutoff point very close to a typical 123 cell's loaded voltage, knowing that these cells have a flat discharge curve. Apparently the tarnish was enough to pull the converter quite literally right to the edge between proper operation and flickering, which lambda had told me was a sign that the battery was about to die.
But does this really make any sense? /ubbthreads/images/graemlins/confused.gif
I also recall my stepfather, who's an electrician, using some sort of goo on wiring he was grounding to the copper pipes in my basement. Or maybe I don't remember that, I don't know. Does such a goo exist, possibly some sort of conductive stuff that acts as a barrier to oxygen, keeping the copper from oxidizing?
My favorite small light is a lambda-modded E1E with copper pill. Great walking light! Low dome LED, yet packs a wallop in total output, and even in distance for such a small light! /ubbthreads/images/graemlins/bowdown.gif
Lately the light would intermittently start flickering, even with a fresh battery. I briefly suspected the LED was blown, but that wouldn't make much sense, as this thing is VERY well heatsinked. Then I started thinking about how contact was made with the E1E body. The positive connection is the usual raised solder ball touching the top of the cell, so no surprise there. A visual inspection suggested it was in good shape.
The negative contact point, apparently, is a little more precarious. The ENTIRE outside of the copper slug is negative, but it appears that only a narrow lip presses against the top of the E1E battery tube. Also, the copper was tarnished, though not horribly.
Finally I couldn't take anymore. /ubbthreads/images/graemlins/grin.gif
Got out some copper cleaner, took the slug out of the light, and veeeery gently rubbed a little copper cleaner into the copper along the sides, taking care not to wet top or bottom. (In reality getting wet probably wouldn't have mattered, as both top and bottom are epoxied solid.)
Then I "rinsed" by wetting the corner of a sponge and running it along the side, and driec thoroughly with paper towels.
Put it back in the light, and voila! The problem is seemingly gone, at least based on the limited runtime I gave it. /ubbthreads/images/graemlins/cool.gif
Here's what I suspect happened: the tarnish introduced a resistance just high enough to drop the cell's voltage below the threshold for the converter in the pill. I suspect that lambda chose a cutoff point very close to a typical 123 cell's loaded voltage, knowing that these cells have a flat discharge curve. Apparently the tarnish was enough to pull the converter quite literally right to the edge between proper operation and flickering, which lambda had told me was a sign that the battery was about to die.
But does this really make any sense? /ubbthreads/images/graemlins/confused.gif
I also recall my stepfather, who's an electrician, using some sort of goo on wiring he was grounding to the copper pipes in my basement. Or maybe I don't remember that, I don't know. Does such a goo exist, possibly some sort of conductive stuff that acts as a barrier to oxygen, keeping the copper from oxidizing?
