Push notifications vs background service battery consumption

I’m making my first ionic app, where the application/user should get a notification from server. Currently I have implemented this as background-service, where the application sends query to server every 5 minutes and if there are some new items it will notify the user. Everything works fine.

What I’m concerned is battery life,…so I have found notifications-push plugin where the notifications are sent via ionic server (which for example can communicate with my server). Here positive thing for me is that the user will get the message immediately when it is send from server.

My questions are:

  1. Will be the battery consumption better in push-notifications example (ionic server)?

  2. Will the push-notification implementation work when the screen is off? (off-course with wifi-on,…etc)

Hi, this question out of topic. But maybe you can share how did you implemented background service with ionic?