https://marco.org/2010/04/09/in-order-to-get-10-hours-of-battery-life-the
In order to get 10 hours of battery life, the entire iPad (including display) has to pull less than 2.5 Watts on average.
— iFixit. Wow. I hadn’t bothered to do the math in my head, so I didn’t realize how impressive that was until now. That’s insane.
If we didn’t have proof right here in front of us, I’d insist that 2.5W total power consumption for a computer with a brightly backlit 9” LCD while playing videos and browsing the web was impossible.