I have the iPhone 6 Plus, so not an Apples to Apples comparison, or is it... I had the iPhone 5 prior, and the 6+ does have way more battery life. Typically when I charge it at night it is around 80% or more charged after a full day of being on. I don't use it a lot, but I do have phone calls, look up stuff on it, etc. Even days when I talk for 3+ hours on the phone, the charge will indicate 60% or more. So it does really well at battery management. Granted the 6+ has a bigger battery than the 6. You might check cellular usage and permissions. If you have a lot of apps that like to phone home during down times, you can correct their attitudes and prevent this. If you run BT all day but rarely use it, turn it off. If you are around a WiFi network you can turn on the feature that allows you to make phone calls over WiFi rather than cellular radio, and that most likely saves battery and makes for better calls if your cellular coverage is spotty at home or work.