Batboard

Hi everybody !

I am busy making a keyhangerlight, you know how hard it is to find the keyhole in the dark, for your car, house, etc..
Now, because I want it to be a challenge, I have certain parameters I wanted to meet:

- It has a led driver (PR4401) so even with low battery voltage, the LED always gets the same current. (until voltage gets below 0,9V)
- It uses one AAA battery (even old ones should be sufficient)
- I want it to use as less current as possible so I don't have to change the battery all the time...

So my question is: Does any of you know of a white LED, who runs on really LOW currents? I've found SMD LED's, but I prefer a standard 3 mm. Light output doesn't need to be much, just enough for viewing the keyhole.
I find it hard to find white LED's, the traditional colours aren't that hard to find for low current's for example 2mA instead of the standard 20mA. But white LED's seem harder to find..

I see lot's of light power here, with all the new technologies on cree LED's, and here I am asking the opposite

First of all: why use a white LED? If you want to find a keyhole, you don't care about color rendition. Use a green LED, it will provide more usable illumination per watt than a white LED.

Second: you can use a high brightness LED - just run the current down. Feed it 0.1mA, and it will make a small amount of light.

Third: Depending upon how much light the location gets during the day, maybe modifying a solar garden light would be a solution?