20 for $20 LED Lights

[Semarin]

[ QUOTE ]
The_LED_Museum said:
Judging by the emitted LED color, I don't believe these are Nichia LEDs. Guess I'll have to take one apart and examine the LED more closely.

[/ QUOTE ]

Thanks Craig,

Please let us know the outcome /ubbthreads/images/graemlins/smile.gif.

 

[The_LED_Museum]

See above...I disembowelled a white LED one and checked its LED.
I'm 99% certain it is not a Nichia LED.

 

[Semarin]

Thanks for the info, don't think I'll be buying any of these then. If anyone knows of some decent sliding switch type LED keychain lights with Nichia LED's in them, feel free to PM me. I'm looking for a new supplier (preferably US) to replace my current model that I import from Taiwan.

 

[UnknownVT]

[ QUOTE ]
The_LED_Museum said:
I'm guessing the LEDs themselves are the culprit here. They aren't Nichia, so they may not be able to handle the higher currents that Nichia LEDs can.
This is a Loo Loo Enterprises product (see my "Flushlight" review), and uses what I believe are Chinese LEDs; of which I do not know the specific manufacturer.

[/ QUOTE ]

Craig,

Many thanks for that input - so do you think these are -

(1) just some bad LEDs?
or
(2) LEDs with rating that are marginal in handling currents that even 2x 2016 coin cells can produce?

If it's (1) then I can put it down to bad luck to have found two that strobe.

But if it's (2) and the current/power handling is marginal - then I would guess that these LEDs are eventually going to fail/strobe?

Anyone else have these LEDs strobe - other than my 2 and one other reported case here?

Thanks.

 

[kubolaw]

I have some of the 20for$20 lights on order, so I'll test a few to see if I can duplicate your strobing failure. At this point I actually prefer the original 20for$20 light (simple squeeze, no constant on) due to what seems like a more robust design and construction (which is why I had to also order some of the "super tough" LED lights).

Darn you CountyComm for carrying all this neat stuff!! /ubbthreads/images/graemlins/tongue.gif

John

 

[snakebite]

i have two of these and the led looks just like the chiwing/besthongkong leds.
the china leds are slightly longer than nichia's and the nichia is slightly tapered rather than cylindrical.

 

[paulr]

I've never seen this strobing phenomenon but I've had one of the older-type CC lights burn out altogether. Really, LED's are designed to be reliable when you run them within the manufacturer's specifications in terms of drive current. It turns out that they work pretty well, and light up brighter, at even higher current than the specification. That's called overdriving, similar to overclocking a CPU. But if the manufacturers felt they could guarantee the leds to be reliable at those higher currents, they would have put that higher current in the specification. So whenever you overdrive, you're taking a chance.

The 2x2016 lights, and the Arc AA and AAA and CMG Ultra all overdrive their LED's. The Photon II uses a Nichia LED similar to the Arc (maybe not identical) and overdrives it even harder than the Arc does when the coin cells are new. If you're concerned about a light failing on you, whether through LED overdrive, some other type of electronic or mechanical failure, or accidentally dropping the light down a sewer, the answer is always the same--carry a spare. However, backing off to 1x2032 from 2x2016 at least avoids the overdrive in the coin cell lights, and results in very long runtime per battery.

 

[jbrett14]

First of all, at $1\light, we certainly shouldn't expect a lot. You get 2 batteries, an LED, a split ring, and a light housing, all for a buck. If I had 5 out of 20 fail, I wouldn't care. The fact that some of you guys are having strobe issues, tells me one thing: we shouldn't be dependent on these lights with our lives, but they still make great keychain lights. If it starts strobing, throw it away and put another one on the keychain. I've got to believe that these LED's are some kind of rejects from an inferior manufacturer. Rejects don't necessarily mean LED's that didn't work or didn't put out bright light, but rather an LED that didn't meet the criteria to be used as Grade A quality. Love all the reports that you guys post. Keep it up. Vincent, as always, your posts are very interesting and elaborate. If I have one of mine start malfunctioning, I too will post. I got 23 in my first order. Just ordered another 20 (23). I let my kids use them, so they are definitely put to the test.

 

[geepondy]

One of mine was dead from the get go and I took it apart and verified the LED was the culprit. I never had a dead LED that I didn't blow up myself. Even so, I saved the two batteries for use in my photon so still more then got my dollar's worth.

 

[UnknownVT]

[ QUOTE ]
geepondy said:
One of mine was dead from the get go and I took it apart and verified the LED was the culprit. I never had a dead LED that I didn't blow up myself. Even so, I saved the two batteries for use in my photon so still more then got my dollar's worth.

[/ QUOTE ]

That's it - the 20 for $20 CountyComm LEDs are tremedous value for money - they deliberately put more than 20 in a bag to make up for any malfunction -

So value for money was not the issue, and still isn't, even if I have had 2 strobe on me.

It was the simple fact I thought LEDs were reliable and virtually indestructible - especially when used with tiny coin celled batteries - so when I had the first one strobe on me - I thought nothing ahout it - didn't even mention it here.

However when a second one strobed - I thought it was worth mentioning - as I said, to me it was akin to being struck by lightning twice.......

The question stil remains - whether it was just a couple of "bad" LEDs - or are these LED rating so marginal that it is likely that they will eventually start strobing.

If it's the latter then this is BAD NEWS.

However I suspect I simply have had a couple of bad LEDs -
since there does not appear to be that many cases reported of strobing - just my 2 and one other case so far, and many people seem to have very positive experiences with these 20 for $20 LEDs.

Nevertheless I would be grateful to hear from anyone who has had these LED strobe on them.

Thanks.

 

[paulr]

It's pretty easy to change leds in those lights. I swapped an "ocean green" lsdiodes.com led into one of mine. I dunno if that's a higher quality led than what CC ships with.

 

[UnknownVT]

[ QUOTE ]
paulr said:
It's pretty easy to change leds in those lights. I swapped an "ocean green" lsdiodes.com led into one of mine. I dunno if that's a higher quality led than what CC ships with.

[/ QUOTE ]

Absolutely PaulR. I have in fact put the Yellow LED from my old EDC Photon I into the body of the first 20 for $20 that failed/strobed along with its 7 year old tired 2032 battery - which I have just changed for a new one

The second LED that strobed works (without strobing) when powered by a single 2032 at about (my guess) half the intensity -

That second LED is now powered by that tired 7 year old 2032 - it is now a very dim white light - which I want to experiment with as a stealth close-task light.....

So in all, despite two strobing failures I have actually got a lot more out of these lights.

I would like to try a high efficiency blue-green/cyan colored LED with a single 2032 (ie: under-driven) to see how that works as a close-task light - any suggestions on where I can get one or two of these LEDs without paying through the nose for them and shipping?

 

[paulr]

lsdiodes.com charges $2 for shipping, not bad compared to most places. Their blue-green leds aren't the world's brightest though.

1x2032 runs a green or white led just fine as a stealth light. I think green may work a little better than blue-green (longer wavelength->lower forward voltage). Photon originally shipped 1x2032 in the green-led versions of its lights and I've been using one for years.

 

[3rd_shift]

Also check out www.besthongkong.com (a cpf sponsor) and see if they have what you want at the price you want. /ubbthreads/images/graemlins/smile.gif

 

[UnknownVT]

[ QUOTE ]
UnknownVT said:
That second LED is now powered by that tired 7 year old 2032 - it is now a very dim white light - which I want to experiment with as a stealth close-task light.....

[/ QUOTE ]

How dim is my new "stealth" light made up from the 2nd more recent faulty/strobing 20 for $20 LED on that 7 year old tired 2032?

Pretty dim, as one can see from this comparative beamshot -

The regular 20 for $20 is a bit too bright for reading on white paper when I'm in a dark environment.

The dim one is comfortable for me to read even small print when the light held between 6"-8" from the paper - which is a normal comfortable distance.

In a normal room lighting environment - the dim LED's hotspot just becomes indistinguishable at about 10" away from the surface of a piece of white paper - so at 6"-8" the light intensity is slightly better/brighter than normal room lighting for reading.

Strange that I could be so enamored with a "faulty" dim flashlight /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/crazy.gif

I'll post a separate thread with more comparison beamshots.