1st way :

1) settings
2) Applications
3) backgrounds tasks
4) block everything u dont need
5) open advanced
6) check the apps that working on your phone
7) try to Uninstall the apps that u dont use

2nd way :

1) open settings
2) battery saver
3) make the battery saver ON
4) open advanced
5) pick Now until Next charge or Always

now u turned off the apps that running without u open it
if u want to update an app like the Weather, u can just open it then close, it will be updated

The scnd way affected me very much, battery now 43%
last time charged before 20 hours
I used Youtube,Store,photos and twitter and like everyday usage like FB

Also close Wi-Fi , Bluetooth and NFC

Good Luck and am waiting for u all ;D

Now no battery problem for me