No, this is the first time I have encountered such a case. I try a little, I don’t even know how to be, because I never had such questions before, okay, I’ll break through
The most important thing is to turn off location detection in the settings and use the screen brightness as low as possible. Next - turn off notifications that you do not need, close applications by swiping them from the list of running ones and turn on power saving mode for them. Also, from the development menu, you can switch the phone to a more saving mode. And make sure that no data transfer interfaces (WiFi, bluetooth, mobile data, GPS) are in vain.