I'm supposed to produce bicycle lamps.
The LEDs should be white, and super bright as possible, use batteries A23 12V, with a resistor (I'm using 2 MOhms,) and last for around 48 hours.
The problem is that the LEDs using this configuration, lose brightnrss after 15 seconds (maybe lose 50-60% of the brightness.)
I have tried already with 3 different kind of LEDs, always with the same result.
By the way, I used the same resistors and same batteries 2 years ago (with leds that worked,) and now I can't find LEDs that actually work.
Basically I ran out of LEDs, but now I can't find the correct leds.
-What is your recommendation? - What are the correct leds?
Characteristics of the LED I am using and fail:
- Producent (varemærke): OPTOSUPPLY
- Type diode: LED
- LED-diameter: 10mm
- LED lysfarve: Kold hvid
- Lysstyrke: 8400mcd
- Lysvinkel: 30°
- LED-objektiv: Diffus, hvid
- LED strøm: 20mA
- Driftsspænding: 2,8 - 3.6V
- Montering: Printhul
- Front: Konveks
- Benafstand: 2,54mm
Any recommendation? Sorry, Im not an expert, I am a bike mechanic. I used to produce these lamps, and they used to work.
*update: I uploaded a photo of what I am trying to do. I checked that the batteries basically die after few seconds, so I realize that the consumption is extremely high. I need new leds. But I dont know which ones. As I said before, with these batteries and resistors, hundreds of lamps have been produced in 2017 and 2019. I checked an old lamp, and it has exactly the same "set of colors" resistor, and same battery of course. So the problem is the leds. (or maybe the resistors can be the same color but be different too? I dont think that).
Here is a photo of the "official" lamp that has been produced for nearly 10 years. I dont have specifications of the original leds. They are very bright, and battery last for a loooong time. Maybe the "mcd" is lower?