That’s because there are so many more pixels on the X’s screen, and so many things to keep you using the phone. I’d say I spent quite a bit of time each day unlocking the iPhone with Face ID just because I was fascinated by it.
Even at the end of my busiest day, it still had 10 per cent of juice left by bedtime."
Mashable found it to deliver on its promise, too:
"Battery life is rated at a robust 13 hours for video playback. My initial experience with the phone didn't get me that far, but that was because I choose to restore the iPhone X from my iPhone 7 backup. The more data you have on your phone, the harder the new iPhone will work to catch up, especially when connected to Wi-Fi. Over the next two days, and as the iPhone X caught up to my backup data backlog, I watched my battery life get better and better. As I write this, I have 47% battery life left after 8 hours of use."