Hello all,
Here are a list of a couple of things you can do to resolve some of these issues you might be having:
1. Turn your device off and on again: Okay this may sound like a simple one, but this really does help. Think about it, when is the last time you actually turned your phone off and just let it sit there for a minute or two? When your phone power cycles it rotates and deletes information it no longer needs. If your device is stuck trying to run some background process, turning your device off and on again will force that process to stop and ultimately help battery life. Plus, it is just good in to do every once and a while to keep your phone running smoothly.
2. Reset all settings: You can reset all settings by navigating to Settings > General > Reset > Reset All Settings. This goes and performs a reset of the operating system on the device while additionally puts all the settings back to their original factory state. Remember after reseting all settings to go back and change your auto-lock and background app refresh.
3. Erase all content and settings: When all else fails, regardless of what version of iOS you're running, you may just need to completely clear your user on the device. iOS is essentially broken into two folders. There is the system folder and the user folder. The system folder is where your OS sits and is read only, meaning that you cannot physically change this information. The user folder holds everything that is yours (i.e. Apps, Photos, etc.). This is the only place that is read and write (meaning you can change the information in here). Most of the time, this is where issues arise that can cause battery problems. Erasing all content and settings securely gets rid of all the information in the user folder while leaving the system folder intact.
Hope this helps!