10-Watt LED Modules, Part Two.

Just yesterday I posted a review of some poor-quality 10-watt LEDs.
Today I received some 10-watt LEDs, bought from a different seller.

Last time, I got defective LEDs: all 5 out of 5 were dead.

Today I found a little package of LEDs in my mailbox—the ones I ordered after the first batch. The timing couldn't be better. This will be a short review, since there's not much to say about them except that they work. ALL of them.

I placed the order on March 25, and they cost me 11.90 for 10 pieces. Even cheaper than the first ones.
The seller sent them by Hong Kong Post without tracking (the tracking still shows this —
2014-04-11 00:00 Bagged, Shenzhen, Ukraine).
The seller warned me right away that he would send them this way, so I wasn't particularly worried.

They arrived in a regular envelope, inside an antistatic bag wrapped in bubble wrap.


As you can see in the photo below, everything is in perfect condition, just like the first time with the other seller (although those also came in a cardboard box).


The first LED, and all the others too, work perfectly normally, even at low current. (I accidentally looked at one without the glass cover, and now I've got spots in my eyes.)

Just one photo, since the rest would have looked identical.


A couple of the LEDs initially light up with only two of the three chips (at around 50–100 mA). Once the current goes above 100 mA, everything works normally. The chips' characteristics vary a bit, but at this price I'm fine with that; I don't see anything wrong with it.


When the current goes above 100 mA, the others turn on.


The LED shown in the photo behaves a little strangely at low currents.
Up to 50 mA, two chips shine brightly (you can see them in the photo). Above 50 mA, they go out, while the two lower ones start to glow more dimly (they're faintly lit in the photo). Increase the current further, to 100 mA, and all 9 light evenly. As I gradually reduce the current, they all dim evenly at first, then only the two lower ones remain lit. If I switch the LED off and repeat the experiment, the same thing happens. I'll see how it behaves from here on.

At 900 mA, the voltage across the array is 9.72 V, so the power is 8.75 W.


In my opinion, these LEDs are perfectly decent for the price. The previous ones wouldn't work under the same test conditions.
Unfortunately, I can't measure the luminous efficacy of these arrays, but they seem quite bright, and the color is perfectly fine too—not too green or too blue.
Once I've put them to use, I'll probably add more information and photos to the review.

Thanks in advance for your feedback. I hope this information was useful.