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.
I’m not sure but i think i heard there was a solution for some rooted phones to stop charging at a specific battery level (magisk Module maybe?). Similar to al dente on a mac. Maybe you could look into that
Android can do that by itself these days; at least LineageOS can.