Mac-book keyboard backlighting – Does it drain battery life?

Most people already know that the display brightness has a huge impact on your battery life. The brighter the display the more power it uses and faster it drains your battery. But how about keyboard backlighting on a notebook. It’s just a led with no logic of super complex circuits behind it. Cant be that power-hungry right? wrong. Here are the numbers:


Hardware  Setting  Browsing with 180 cd/m2
Mac-book 12″ Backlight off run time 10h35m
Mac-book 12″ Backlight minimal run time 9h58m
Mac-book 12″ Backlight maximum run time 8h20m

The difference between maximum brightness and no backlight is more than 20% ! I Would not have though that it would be such a big impact on the whole device.

When you keep the back-light brightness to the minimal setting it a little bit over 5% deduction of your total run time on the battery.

While the Apple Mac-book has a complex keyboardlighting system with 16 different levels of brightness another laptop has been put to the test with a simpler on/off design.

Hardware  Setting  Browsing with 180 cd/m2
Medion S3409 Backlight off run time 6h7m
Medion S3409 Backlight on run time 5h14m

This is also around a 14% difference.


Light doesn’t come cheap. You can save power by turning it off or keeping it to a minimum.


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