calculation of battery performance by way of SOT is wrong. you mean to say one had nothing else to do but to sit in front of your phone for 6 or 8 hours glued to the screen. That's impossible unless you have nothing else to do. there are apps working in the background too which consumes battery. so it's not possible for accurate data on battery performance as it depends upon individual usage. For me I am happy as my battery gives me a day and half till my next charge. So I am not bothered about screen on time. Good day.