The battery life of my XS max is also very impressive. Its night and day compared to my old 6s+. If I just use it normally, I have around 65-80% of battery left at the end of the day. If I use it heavily, like over 4-5 hours a day, the lowest battery life % left I had since I god my phone last october was around 38%. The normal day when I'm between the normal and teavy use, I usually have 50-55% battery left. I never go below the 30% mark yet.
Its actually have a better battery life than both my iPads.