Board Thread:Game Discussion/@comment-71.191.73.96-20130624013927/@comment-9605025-20130624221734

It's the trade off for not storing anything on the device itself. Even if you're not doing anything it is still connected and communication with the server which takes a lot of power. My dad had a similar problem with apps left open on his iphone and as soon as I told him to shut all of them down his battery life increased significantly and the phone stopped getting hot.

I particular for this game, it is constantly checking for rank updates and help requests even if your are using something else.