Every single phone I've had I've installed clean ROMs without any extras, and with multiple governors to choose from. Undervolting was useful every single time,

Every single phone I've had I've installed clean ROMs without any extras, and with multiple governors to choose from. Undervolting was useful every single time, too. But that's just optimizing your phone. Sadly I don't know any phone that will last more than 5 hours of total screen on time (web browser, emails, notes app, messages, with 3G/wifi/Bluetooth on). Every generation has some ridiculous additions (4K displays, LTE, more RAM and Ghz) that make battery life the same as a good old Droid. Ive been using a HTC One M8 and can squeeze 5 hours of screen on (screen+3G/Wifi+BT, never LTE) time even with adaptive brightness on (which runs it at 100% a lot of times), on CyanogenMod (Android 5.1) with no extra crap. That's enough for a good day of use - charge at night, use during the day, it's at about 30% in the evening. GPS use can kill it though. I would love a phone that can last 12 hours straight like that :)