How do I stop apps from running in the background on an LG G6?

[Android Central Question]

My mom has an LG G6. After her phone updated this morning, she now gets notifications showing when apps are using battery in the background (something I've had for months on my phone). She wants most of her apps to NOT run at all in the background.

On my Samsung Galaxy S8, there's an "Always Sleeping" page that you can add apps to from a list. I can't find anything like that on her phone, and although I found a single app that has the option to keep it off in the background under its info page, the other 5 or so I've checked don't have it.

LG G6, Verizon Wireless, Android 8.0.0

 

[kct1975]

While it is not perfect...I would recommend installing Greenify...

https://play.google.com/store/apps/details?id=com.oasisfeng.greenify

 

[danbitman]

I had the message "Exchange is running in the background" on my LG G6 and I simply pressed the message (long, not short) to open an authorisation window for this. On this window you have just to put the authorisation on Off.

 

[ManiacJoe]

If you don't want an APP running in the background, use the "back arrow" button to exit the app back to the home screen. All the other buttons leave the app running in the background.

If you don't want some SERVICES running in the background you probably need to use the settings of the associated app, but that may not help.