These tips should help with 20.1 with the battery and stuff.
So, to maintain battery, you should use the charger that was provided when purchasing your device. Because those chargers are made for your device that you use.
Do not unplug your device during flight
When not touching the screen and leaving it alone, you device will start to recharge
Sitting in a dark room with the brightness all the way down allows for great battery saving
Turning on Night Mode with apple helps bring out the details and enhances the quality without draining your battery
this is what i noticed, hope it helps