do black background save battery?

[Guest swisstourist]

all in the title.

[Guest ThrashMan]

no

[Guest Stephen J. Knill]

all in the title.

As above, No. If comparing between still images.

However non-animated backgrounds will use less battery than animated ones. But only by a fraction. (Takes CPU power to process the animation, remove that and there's less for the CPU to do... effectively lowering the power requirements.)

[Guest TCTUK]

Wouldn't it depend on the model (OLED or TFT)?

[Guest ColdEmbrace]

Wouldn't it depend on the model (OLED or TFT)?

apparently OLED use a little more energy than TFT's

[Guest Roph]

Displaying a bright colourful image, an OLED will use more than an IPS LCD. But displaying dark or black images, the OLED will use significantly less. OLEDs that are "displaying" pure black emit no light at all and use no power.