My Solution

The issue has been reported across iPhones and iPads, so it appears to be a software problem. Ars Technica ran extensive battery tests on iOS 7.1 and found battery life to be slightly worse than before.

Former Apple Genius bar employee Scotty Loveless has a test to help check whether your phone has a battery drain problem.

Go to Settings > General > Usage. Write down the standby and usage times. Press the lock button and leave the device for 5 minutes.

Now go back into the Settings menu and recheck the Usage stats. Your standby time should have increased by 5 minutes and Usage time decrease by 1 minute . If your Usage time rises by more than 1 minute, your phone is not going into Sleep mode properly and you have a problem

Contrary to popular belief you dont need to close apps manually. When you are using an app, iOS freezes the other apps where you left them. They are not running in the background unless background data or location services are on. 

Constantly closing apps and then re-opening them drains more battery as they need to be loaded into the RAM.

Sometimes push email gets stuck in a loop and this drains the battery constantly. Turn it off and then check the usage stats from step one. If the battery drain reduces, you’ve found you’re problem. You can also try changing the fetch times to once every hour, 30 minutes, or 15 minutes.

Constantly checking the battery life of your device can have a detrimental impact. If youre switching your device on every five or 10 minutes to check the battery percentage more power is being drained. Try turning off the indicator.

Double check the brightness setting. The screen is the biggest consumer of battery and if you’ve got it set to full blast this will drain the power quickly. It’s a good idea to leave it on 75 per cent and also use the auto-brightness feature. Go to Settings > Wallpaper & Brightness.

6 - Turn off Location services

Location services is also a massive battery hog. To turn this off go to Settings > Privacy > Location Services. Turn off Bluetooth as well from the quick settings menu by flicking up from the homescreen.

Do a hard reset (this won’t erase any data). Hold the home and power buttons for ten seconds until it restarts. This reboots the phone and kills any potentially power-hungry background tasks.

Charge your phone to full capacity, then use it until the battery dies. Apple recommends doing this once per month in order to retain maximum battery health.

Reset the phone completely. This should be the last option as it wipes your data. Connect your phone to your computer and restore it in iTunes as a new device. Do not restore from a backup.