Check task manager on Phone and see if it is running in the backround . There will be a opsion kill that function.
Or you can apply the ultimate Android battery saver: If you don't use the app and you also don't trust what it might be doing in its spare time, remove the app from your phone.
This happens to me too. I will open the app, use it, then close out of the app by clicking on the home button. I will come back later and it shows as 2%-6% battery usage. I found that a way to close the app for real is to go into your battery settings, then force close the app. It is a pain in the butt to keep doing that, but it does work! There is no reason for spectrum app to run in the background.
I had other apps that got so bad like this that I had to remove them from my cell phone. Accuweather used up 25%!