The reason why Chinees Led's should be avoided.

I was at Frys Electronics the other day and was reminded of why I long ago vowed to stay away from off brand Led's made in Hong Kong.

Notice that nearly half of the Led's on this reading light are burnt out and the ones that are on might as well be burnt out they were so dim. I have been noticing these Led's drop like flys over the past year or sow every time I go to the store.

Could also be the battery is drained

Edit: Oh, those are not flashlights right, forget what I said

They are hit or miss, I have picked up a few cheap lights that had blue-green glower's and blinkers. Most have been good. When they work they tend to be whiter if not as bright as the Nichia's.

The bad lights have repairable so far. It is a pain to buy a new object and have it go bad out of the box.

They are hit or miss for sure.

But, if you search around, you can find reviews that greatly enhance your chance of procuring a real winner. The lights with the wavey "Police" banner tend to be really good ... as are my Ice Cream II lights (21 LEDs).

Most of the "problems" with Chinese LEDs stem from the way they're used. To save money they're either direct driven or at best used with a resistor. When driven within specs they're reliable at least as far as not burning out. Some types tend to degrade somewhat rapidly compared to Nichias. However, they're also much cheaper than the Nichias plus available in a wide assortment of form factors/colors. In many cases the beam quality and tint are better than Nichia and they're at least as efficient. I'll also mention that Nichia has a habit of annoucing great sounding products which can't easily be bought. For example, last year they announced that 85 lm/W 5mm LEDs would be produced by September 2006 and 100 lm/W ones in the beginning of 2007. Well, where are they? All I see available on their website is the Nichia CS which has efficiencies in the 60 to 70 lm/W range, depending upon bin. At least the best Chinese LEDs aren't unobtanium.

I bought a couple of 20 led USB lights. They both started burning led within a few days. Turns out the resistors used were crap and were responsible for the burnouts.

Just overdriven leds.

The nominal current values for 5mm leds are in the 20 - 30 mA range. Some of those unknown manufacturers just overdrive the leds even to 80mA to make them look brighter.

The logical result: Leds go fryed very soon. My worst led experience was with something simmilar to that. It lasted less than one week.

Worst think about that is the bad impression they can cause to general people, leading them to think that leds are unreliable and failure prone.

My first bad experience with Hong Kong manufactured lights was about 5 years ago. I bought a 100 pack of ebay and a few months later another 100 pack from a nother seller. They seemed quite bright and had a good tint to them. I used them to light my Room which was powered by a 12V solar panel system. They were driven at about 20ma average it could reach ~25ma when the panels were putting out and the battery was fully charged (close to 14V). 25ma is a little over speck but nowhere nere abuse. I had several maby about 5% failure over one year of continuous use and after the one year all of the Led's were noticably dimer, some substantualy.

In all farenes I have not ran any of my Nichia CS Led's for one year in a similar set up to caompare results. I have ran Luxeons and they have held up remarkably.

50k hours.. if you are lucky

josean said:

Just overdriven leds.

The nominal current values for 5mm leds are in the 20 - 30 mA range. Some of those unknown manufacturers just overdrive the leds even to 80mA to make them look brighter.

Click to expand...

Yep, that seems to be the main problem.

I recently bought a 10-pack of flashlights that each have nine 5mm LEDs, direct-driven by 3 AAA cells. A quick check with an ammeter revealed that they were drawing anywhere from 0.6 to 0.8 amps (or roughly 65 to 90 mA from each LED, assuming perfectly equal current draw) - not exactly conducive to a long lifespan for either the LEDs or the batteries! The problem could have been solved with the addition of just one resistor, but nope, that would have increased the product cost too much...

I can't believe a store that is trying to sell these would leave out a faulty display model. I guess they don't really care if anybody buys them or not. But, given the quality, it's good for the customer even if it's a stupid move on the store's part.

What did you expect from Fry's?

"Hello, sir, did you find everything you were looking for today?"
"No, I didn't! I was looking for some soldering equipment [Helping Hands - the reps didn't even know what it is after a description] and battery holders [4AA side-by-side or 1AA, I don't remember which] and didn't find what I wanted. My friend here was looking for a music CD [something new and popular] and you guys didn't have it!"
"Oh, that's too bad."

The first and last speaker is the Fry's cashier. The second speaker is ME; this isn't hearsay.

Fry's service is the absolute worst, but you can get pretty good deals on some nice stuff. It's definitely a tradeoff.