[1900k edition is in!] WTS: 1900k-5800k 5mm LED 95+ CRI

Very nice little bullets. Are the LEDs up to the specs of this lights? I imagine current might be somewhat higher than 25mA. No?

Thanks Barkuti!
Good idea :+1: , however I had to pay extra for shipping with batteries :rage:
Took also a few Fasttech flagships: authentic

The reason that I didn’t plan to go for 5600k is that Yuji still sells 5600k 5mm (and I believe there are still some of these or similar clones selling in the wild). I don’t plan to step on their toes (yet). But if enough people want me to do it, then I will do it, no objections :wink: But maybe I will, after the 2nd batch.

Do you already have an idea how to get the PCB out? Heat? Brute force? Both?

Nice find. Bought a couple of them, too :-).

I have no idea. Will see when I get them in hands.

This is the cheapest sale for the Mateminco BL-01 in AliExpress: https://www.aliexpress.com/item/32875327787.html

Crazy expensive.

If you wanna shop batteries at FastTech better pack some battery items together, saves money.

The battery shipping subject did a lot of harm to sales of harmless batteries and harmless battery powered stuff. I'd buy small shipments of alkaline or silver coin cells from china in the past and while it still is possible for cheap, it's not that easy.

Some sellers (in AliExpress) just @#$% with the “selected carriers for batteries” thing and ship the stuff declaring it to be something else, at least sometimes I think.

Pity.

BTW:

I also took some simple 5mm LED flashlights from local market but with a dynamo. I hope it’ll withstand wide temperatures range in my car. We’ll see.

Link for the same item on Ali.

rngwn, i’d like 30pcs of 5600k once you get them

I can’t promise you anything. But I personally wouldn’t worry at all about the current that 3x LR41 button cells could send to this LED. :smiley:

At least, given usage time is 3 hours. Must draw something less than 25 mA, given a capacity of 25 to 33mAh each cell. If my math is ok, that is :+1:

A lot less than 25mA on average, this is for sure. The actual power delivery efficiency is quite low, such cells aren't designed for high drain. Simplicity and reliability are the main factors here.

If you need 'em cheap, check this ad for example: https://www.ebay.com/itm/10PCS-1-5V-AG3-LR41-392-SR41-192-Alkaline-Button-Coin-Cells-Watch-Battery-Sturdy/382209158751 :-)

They’re powered by three LR41 alkaline button cells. The 45 lumen stock rating strikes me as extremely unlikely.

Those cells can’t push much current. I don’t expect it would be any problem.

Hey, thanks. Yes, that’s what I was thinking, but you never know.

Even the “half watt” LEDs can’t reach 45 lumen output. They are generally only rated up to 100mA @ 3.4V, which would translate to 0.34W of power. To get 45lm out of that, you would have to be getting over 130 lm/w efficiency, which none of these LEDs have. The cheap LEDs in this format are only good for 20mA current. Perhaps they meant 4.5 lumens? That would actually be the likely output of standard LEDs in this format.

Well, that usually is their rating. Months ago I did some testing on a bunch of 5mm and 10mm leds I had lying around, bought in 2006 or so. The 5mm ones would start dieing at 140+mA, and the 10mm ones slightly higher at 180+mA if I recall right.

So, they could be hard driven to some extent (100+mA pulse driven successfully).

It is the same keychain light as the Astrolux TB01, that had a bit different type of 5mm led than usual, with extra thick leads. I never measured the output before modding it but it could have been 45 lumen (so maybe 120mA).

I would like to get some of these LEDs when you get them restocked. Thanks.

So, Barkuti and djozz, are you guys implying that the light in question is actually using a “half watt” LED and overdriving it, in order to get 45 lumens out of it? That would be a strange thing to see. Can somebody test one to find out what the output really is? I’m really curious now.

45 lumens from a 5mm led when driven by 3x LR41 cells? LR41 alkaline cells have very high internal resistance. An alkaline AAA with close to 1000mAh features ≈0.22Ω of IR with little use (Duracell Plus Power AAA at the ≈150mA x-axis point, 0.5 - 1A discharge curves). A cell with less than 1/30th of such capacity would have 7+Ω of internal resistance in the same conditions, which at 100mA of drain/driving current is a drop of 0.7+V for a single cell and 2.1+V for 3 cells in series, this means no chance of hard driving the emitter even with fairly new cells. According to these figures, those 45 lumens are a blatant exaggeration or typical false advertising.

Thu, 09/19/2019 - 23:42; Fri, 09/20/2019 - 15:30; edited for clarifications.

Won’t ship to Germany but thank you :-).