LEDs use very little energy and dimming does not decrease the energy use by much, so the overall effect on battery life should be miniscule.

Yeah this feature is more about reducing the inconvenience some people experience with having that light on the controller.

They're using a bank of rgb smd LED's the same bank are on a ribbon to the main board where a section of the circuit takes a constant 5v through a series of other components to allow fluid adjustment of the brightness on each unit.

While LED's alone don't use much power smd LEDs use more than stock LED's and the PCB setup to run them uses a fair degree of power.

Not a massive amount granted, but enough that disconnecting or dimming them will have a measurable impact on battery life.

Also, see

http://www.neogaf.com/forum/showthread.php?t=723148


>So the LED disabled controller lasted somewhere between 26 and 36 hours of idle operation.
>the LED enabed DS4 lasted was between 13 and 15 hours.

LED enabled: (1000/80) = 12.5 hours
LED disabled: (1000/35) to (1000/30) = 28.6 hours

Are the lights really that annoying? I've only played the PS4 during the day - so the light didn't have any effect on me at all.

I've read the same GAF report, that's why I was asking. It's not that it's a great inconvenience, but I play always at night, and it does tend to glow a lot, so I just used some neatly cut electrical tape and covered it.
Now it does not bother me, but it sure does drain the controller's battery, even when I'm just watching Baseball or Crunchyroll.
It's annoying when the controller cuts off, and all of the sudden my headphones stop working, and the TV starts balsting sound at 2 am (happened a couple of times, now I'm much more careful).

Maybe the lights are a distraction when playing in a dark room? 

it is. Especially if you're controller faces the screen.

I quite like the light while playing at night. especially in Tomb Raider were it flashes like a flaming torch as you carry one around in game

Aftermarket 2200mha battery + led dimming = epic win.

Fingers cross they will have a solution soon.