yes that will RIP your battery.
In the app settings in android allow the app to run in the background and such should be a better solution.
Make sure phone isnt in power saving mode. then...
Settings > apps > app launch > find Poweramp and then uncheck manage auto. enable all 2 checkboxes and then do the same for the Poweramp unlocker app. exit the app and/or reboot device to be on the safe side.