Notification LED's generic power consumption I know that all phones got different hardware, and that leads uses just a little power, but:


What if I set my LED notification frequency to high (like the light will pulse faster)? How much would that chew off my battery?
What about "always on"? How much would that eat? Would it damage the LED in any way?


(I know LEDs are supposed to be durable, but the phone switches them off-on for a reason.. I guess.) 

What I'm looking for is a generic answer, like "it's not noticeable", or "a couple of percent drop".
The power consumption isn't noticeable. Even a tiny watch battery can run a small LED for a few days continuously.

Increasing the blink rate won't change the power consumption at all: what makes a difference is how long the "on" part of the blink is compared to the "off" part. This is called the duty cycle of the LED.

Most LED controllers use the duty cycle to control the brightness of the LED (because LEDs aren't sensitive enough to voltage), so even when the LED appears to be on continuously, it's actually blinking faster than you can see. You can see this by waving the phone around in a darkened room: instead of tracing a continuous line in the air (like a sparkler or torch does), it looks like a dotted or dashed line. If you can keep the waving speed constant, and measure (or estimate) how long the dashes are compared to the gaps, you know the duty cycle.

The only reason for the LED to blink is a human one: to make it more eye-catching, so you can see when you have a message (or whatever).