Smiles..... sounds like a worthwhile project. Which book you thinking of.We've already had to be careful comparing different people's experiences - sometimes people didn't even bother to specify whether it was the smaller or the Plus/Max model they had when quoting numbers! Now it's got even more complicated so kudos to you for remembering to mention screen settings. With dark mode now that probably makes a huge difference depending on usage patterns and whether the apps someone uses most often also support dark mode. For instance I do use dark mode all the time, screen at about 50% (with auto-brightness enabled) and when reading a Kindle eBook with white text on black background I drop about 1% battery per half hour of reading in my 11 Pro Max and that's with screen constantly on (obviously!).
Usage patterns and settings make such a huge difference. I suspect that if I was willing to abandon most of a working week to reading I might even be able to post numbers showing my 11 Pro Max coming off the charger at 8:00am on a Monday morning (for instance), clocking up 40 hours of screen-on-time, and still having 5% charge left at the end of Thursday evening (that's based on 10 hours per day of eBook reading on Mon/Tue/Wed/Thu giving 20% drain per day plus my 11 Pro Max seems to lose 4 - 5% overnight so adding another 15% drain for not seeing the charger on Mon, Tue or Wed nights for a total 4-day drain of 95%). Sitting on a sofa at home reading would also keep all background network activity on more power-efficient WiFi rather than mobile data and not having the phone moving between cellphone masts also reduces battery consumption quite dramatically I find. A day of not really using my phone with it sitting on my desk next to me drains way less battery than it being in my pocket as I travel around London all day for instance.
I'm almost tempted to write off 4 days to see if I could get to those numbers in real life.
I strongly concur with your analysis. I would further add there a quite a few settings that result in tremendous gains in battery charge duration.
Many of these are buried deep in settings like analytics, traffic reporting, and such. These tend to keep the radio chip sending and receiving constantly. There are many articles listing what to consider turning off.
Also using an ad limiter in Safari really cuts down on downloading/uploading the phone does when browsing. Upwards of 80% data can be cut out that you don’t realize is being used.
apps like Facebook also are huge consumers of radio reporting constantly. Some apps like weather apps also report your location constantly. Have mine turned to never or only when running regarding location. Also why do games need your location data, think about it.
There is a lot you can do to extend battery charge, just do a bit of research.