On Thu, 12 Apr 2018 14:11:40 +0100, Richard Jones
wrote:


Knowing this, what value resistor should I use? I'd rather go on the
high side, so the LED dont burn out. If it seems dim, I can lower the
resistor value some. What would be a safe resistance to use?
This will ONLY be used on 12V DC automotive batteries.

I'll clip it together before soldering it on place, to make sure it's
bright enough and working.

Thanks


LED's have a typical forward Voltage drop of about 1.8V Red, 2V yellow,
green, 3.2V blue. So assuming you are using a green one then it's just
a quick bit of Ohms law..
Car battery charged is nominally 13.8V, take 2V off for the led = 11.8.
Run the led at say 10mA then it's 11.8/0.010 = 1180 Ohms. An easy to
find 1k resistor will do nicely.

Thanks, 1K sounds like a winner. And I will likely use a green one too.