in settings > battery you can see your battery health, and have a look what's using all your power if the health is pretty good.
Facebook, Snapchat and Whatsapp running in the background seems to be the thing that's running the most. Over the last 10 days
Facebook- on screen is 5 hours 45 mins, background 4 hours 57 mins
Snapchat- on screen is 2 hours 16 mins, background 2 hours 49 mins
WhatsApp on screen is 2 hours 9 mins, background is 4 hr 4 mins
Is there a way to get these apps not to run in the backgroup but still receive notifications?