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

How about this as a host? It’s 0.5w though, so I don’t know if my LEDs would survive that.

https://www.aliexpress.com/item/32833777655.html?spm=2114.12010612.8148356.12.6afa51e8B6l2WJ

Received! Many thanks.

GREAT! :person_with_crown: :+1:

I’m really looking forward to seeing the results of your testing. :smiley:

Re-posting this old Yuji mod just for ideas:

My first LED swap which didn’t require solder. In fact I only used a screwdriver, wire cutters, and tweezers:

I recently ordered some batteries from Shockli’s aliexpress store and they threw in some freebies with my order. One was this cheapo keychain light. It has a 5mm straw hat LED that is press to activate and has a tiny switch to “lock” it on.

I bent and trimmed the legs of my Yuji 95 CRI 3200K LED

We have light!

I just now am realizing it had 2 stacked CR2016 batteries so I am probably giving this thing way too much voltage? Maybe a 2032 battery would have been more appropriate, who knows. I guess if it dies i’m out 55 cents…

If you still have stock I woukd be interested in 1 pack as well. See the PM.

The CR2016 cells are 1.5V nominal, so two of them would be 3V, which is fine for a white LED.

I dont know anything about the cells but when I look at replacement ones on Amazon it says 3V nominal

Huh. Yeah. I just looked. You’re right. Hmm. Curious thing.

I have used and gifted dozens of these small lights, all the white ones use 2xCR2016 and i have never seen a single one with a fried led.

These coin batteries have a high internal resistance so the voltage drops when you load them with a led.

CR2016 cells are “3V”, but their internal resistance is very high. Thus, 2x in series CR2016 cells drive a 5mm led well.

That and the fact that you don’t turn that on for a sustained period. Even if you overdrive these LEDs and degrade them way faster than their rated lifespan, you probably won’t notice it.

CR2016 cells are indeed 3V. The “CR” code denotes a lithium manganese dioxide chemistry, nominally 3V.

Alkaline button cells are 1.5V and are given “LR” code. The typical form factor is also fatter and taller than lithium coin cells.

A pair of CR2016 cells shouldn’t be any concern, but because of the low forward voltage on the Yuji’s, they run pretty well on a single CR2032 cell, in my experience.

I haven’t done a controlled test, but I’d expect you would get more stable output and significantly longer runtime out of a single CR2032 compared to a pair of CR2016’s, although you might get higher initial output out of the latter. The massive voltage drop the pair of smaller batteries experience is in part due to a lot of energy being wasted on internal resistance.

Either cell does better at these kinds of loads with intermittent use (a few minutes at a time) than continuous use. It’s surprising how much the voltage recovers when a load was removed in a test HKJ did:

Shipped

slowtechstef: RR146459731TH
Noctiluco: RR278756610TH
mitsuki08: RO247700037TH

Thank you so much, rngwn!!! :+1: :beer:

Mine arrived in Denmark today.

My wife have some tee-lights she bought in Ikea :

The tint in the original on the left is perhaps more candle like, but it also has a hint of green. I like the “upgraded one on the right better.

Thanks again for making these available.

LEDs arrived today, thanks!

Got mine yesterday! Thank you!

rngwn, thanks for making these LEDS in good bins available in small quantities for the BLF community :+1:

In my experience replacing a stock 5mm LED with a warm-white high-cri one can turn almost any shit flashlight into a hit flashlight. Well at least in my humble opinion :wink:

Action Halloween projector, 0.69 Euro

Kudos to iamlucky13 for the suggestion of using 2AA direct drive for a 5mm Yuji.

No PWM, no standby drain, no soldering required for 5mm LED swap :+1:
Current somewhere around 25mA with 2 “newish” 1.5V alkaline AAs.
Mod with Yuji 3200K LED.

Q.E.D.

Mine arrived today, thanks!