So, first off, my apologies for not coming back here and updating this thread with my latest findings.
Second, here they are:
I use an app called Ever Accountable (because I am a man, and that in combination with our fallen race yields certain vulnerabilities).
If you don’t know much about this app, it runs as a device administrator and requires accessibility privileges. It also requires permission to keep the phone from sleeping (but doesn’t under normal circumstances - more on this in a moment). This can apparently cause conflicts with other apps that interact with the screen output. In my case, the conflicting app (I theorize here) is Twilight, a handy app that gets rid of blue hues as the sun sets. It appears that having installed EA before Twilight resulted in a conflict between the two that somehow kept the phone from sleeping.
After uninstalling EA, my battery life suddenly became amazing (as your daughter reports). I reinstalled EA after testing for a day; nevertheless the battery life continues to be outstanding. My only guess here is that for whatever reason, EA before Twilight = badness; EA *after *Twilight = goodness.
My battery now lasts over three days between charges which now bests my wife’s phone by a good bit (insert evil chuckle here).
The moral here seems to be: if your battery is draining faster than you expect, take a close look at your apps and see if there are any that might be keeping the phone awake more than they should. This is hard to tell, because the app itself can look like it’s using hardly any battery, but the device (“Android System” in my case) will look like it’s using a ton.
On the G5 Plus you can actually check this.
- Under Settings / Battery, tap on the chart to bring up the “History Details” screen.
- Below the chart you’ll see the percentage of time certain elements have been active displayed as bar graphs.
- One of those elements is “Awake”. If that bar has super-long chunks of being solid (when you don’t remember having used your phone), you probably have something keeping your phone up. (Sorry for the lack of screenshot…I’m using a desktop. If someone wants one I can add one later; just ask.)
To check if a suspected app has permission to keep your phone awake:
- Go to Settings / Apps and tap the app under suspicion.
- Tap “Permissions”. Even if it says “No permissions granted”, don’t trust it. It might be lying (seriously).
- On the App permissions screen, tap the “…” menu at top right and select “All permissions” (this is annoyingly obscure).
- Scroll to the “Other app capabilities” section.
- If you see “prevent phone from sleeping”, this app should stay on your suspects list (though this doesn’t guarantee it’s exercising that privilege, so you don’t know for sure this is the culprit).
Thanks everyone for taking the time to give input.
Cc’ing @devink.yezxwv in case this helps shed some light on your problem.