[pedromsouza]

Whatsapp is draining my battery. If I switch off background update, will I still get notifications? Can I set it of for groups, but keep it on for individual contacts or select which ones should update? If I switch it off, will it improve battery life significantly?

[Tartarus]

Yes you will get notifications for whatsapp even with background refresh disabled.

You can mute individual chats as well as groups so you won't get notifications for those chats.

But in all fairness, disabling anything whatsapp related won't do you any good as whatsapp is already battery friendly, at least for me it is.

In addition, you can check which apps use how much of your battery by going to Settings > Battery. There you will see battery usage per app.