Question: does always on display use a lot of battery?
Answer: According to Tim Schiesser, the always-on display on the Galaxy S7 uses on average between 0.59% and 0.65% of the battery per hour. Schiesser makes the important point that AoD does not consume power when you're actually using your phone, when the screen is fully on. ... That makes AoD relatively more of an energy drain.