My battery-powered LED Christmas lights are running out of power. The red and yellow ones are most faint, followed by blue, but green is still very bright. How come?

Question

Just something I noticed.

In: 0

Answer 1

Different colored LED lights are caused by different semiconducting elements in them. And this also changes their electrical properties. Most notably their voltage drop. Every diode have a fixed voltage across them when they are conducting. If the voltage falls bellow this they stop. As your battery is draining it is not able to supply as high a voltage as it used to. So the voltage have gone down to the voltage drop of some of your lights. This means they do not conduct as much current as they should which does give your battery some more life and it can keep the voltage there for longer. But it will be slowly falling and the lights get fainter over time.