I always start my flight with the following graphics
Rendering Quality High
3D Object Density High
Rendering Resolution High
Texture Quality High
Frame rate limit 30 fps
Now in 22.1, already in flight, only one option can be changed, which is the Rendering Resolution, while the others are not, this is making my phone consume a lot of battery even though it is plugged in all the time
before, on 21.8, already on cruise, leave everything on low so as not to consume too much of the cell phone
today I took off with 89% battery and now I have 57%
In addition to the solutions mentioned above, try setting your brightness to the lowest possible during cruise. This reduces the amount of energy the screen consumes, therefore increasing battery life.
I agree with @TheAviation_YT and @AviatorAlex here. I highly recommend turning OFF anti-aliasing, and even lowering some of your graphics setting may help, too. When I fly long hauls and I’m not monitoring my flight during cruise, I keep my brightness and volume levels to the lowest setting.
7 Hours without charging is pretty good. I can’t do any flight without charging and now since 22.1 it drains the battery even while charging if I don’t lower the brightness. But my IPad Pro is with almost 4 years already quite old so I think that’s to be expected.
Unfortunately, the Asus ZenFone 5z is quite dated now - it was released in June 2018, and it didn’t have too big of a battery on release - just 3300mAh. As a result of the age of the smartphone (and, therefore, the battery), the battery life isn’t as long as when you have originally bought it due to battery degradation over time.
Texture quality was not changeable before 21.8 either - you could only change that setting when not in-flight.
In addition to decreasing the available graphics settings in-flight, enabling Low Power Mode and lowering your screen brightness to the lowest possible, I would also recommend setting the time to Night and pointing the camera straight up at the sky - that way, the screen will consume even less battery. It will only serve you as a temporary solution, though, so if I were you, I would be looking for a battery replacement, or a new device altogether - it’s nearly 4 years old, at this point - and no matter how well you look after your battery, it just cannot perform as well as it used to once.