Hi All,
My iPhone 6 Plus battery life is terrible. I never get through a full day anymore without recharging (I used to be able to do up to 4 days without charging). I'm not sure when it deteriorated like that, but I suspect somewhere between iOS 8.3 and 8.4. As I haven't seen any real complaints after the software updates, I'm wondering if it could be a hardware issue - the phone is about 9 months old.
Go into settings>battery usage>.... and check which app is using the most battery life. It's usually home & lock screen but see what else features on the top of the list. Usually a rogue app that is killing your battery life day in, day out will not only sit at the top of the list but will also have background activity written below said app, which means still running and is likely to be running more often than not resulting in said battery drain.
You can check the last 24 hours or the last week. Post a screenshot here of said list if there's anything you uncertain about.
Excessive battery drain is usually quite simple to diagnose with the right information.
When was the last time you did a fresh install and I don't mean an OTA update or a restore from backup. I mean setup phone as new!
Might be time to do that now.
Also in settings>general>background app refresh,... check which apps are set to refresh in the background. That is they get updated information pushed through to the phone whenever it is available and not necessarily when you need it. A weather app for example.
Check location services and switch ones off that you not using. Settings>privacy>location services... here as well check which location services are currently active, so switched on and with a purple purple arrow symbol next to them, indicating that right now they transmitting...
In fact read
here for a better understanding at what I'm getting at...