Just went through this whole topic, since I also have this battery drain and heating issue on PA 836.
I mostly use PA while out riding the motorcycle, so my Galaxy S7 (android 8.0.0) is connected to my Sena 3S headset, while the phone is mounted on the bike with the screen turned off.
I have a 2 hour drive going home on Friday and back on Sunday, so that is when I use the app for a longer period.
Last Friday going home, the phone was at about 90 percent charge when I left and after two hours listening to music and using Flitsmeister navigation (screen off, only notifications thr