I do lots of testing of apps in real phones, not emulators.
The thing is that the phones must be connected to the PC all day. Because of this, phones battery get swollen and I have to buy phones regularly.
Do you know any android phone which can be connected and on all day all week without getting swollen after a time?
Must be real phones, emulators are descarted.
Samsung phones have a battery protection mode that will stop charging at 85% when enabled. Any lithium pouch cells will swell up if they are kept on a charger at 100% continuously.