Yes, the laptop has a discrete GPU. sudo prime-select shows that it's set to intel. Whether that means the GPU is being proffered or not, I don't know.
The NVidia X Server Settings App opens only a window frame, with no content - there are therefore no profiles to view.
I realise that using the NVidia GPU was never going to give good battery life. I had neither used it nor messed around with NVidia settings before (when I was getting estimated ~10h battery life) - I'm looking to work out what not to update on this fresh install that would occasion the 80% cut in estimated battery life I saw for a prolonged period earlier today.
I'll look into the CPU frequency extension recommended - thanks - though I'd imagine it does the same sort of thing as the SlimbookBattery TLP frontend, but with less control (i.e. it has 'limit CPU profile' opens of Maximum, Medium and None, and a CPU scaling governor options of Powersave or Performance).
There are several commands that can show What Recently updated.
You can try
less /var/log/apt/history.log
Once we see what updated, we can try to figure out what to correct. Maybe.
I would suspect a bad download corrupted a file during an update, rather than that the update brought breakage.
Since I've since done a clean install (didn't bother backing up logs etc) that's not an option now open to me.
If the issue recurs, I'll definitely take a look through the apt history (now I know where it is!).
If the issue had been a download corrupting during an update, what's the general procedure for diagnosing and fixing it? Reinstalling the last x number of packages?
Presumably working out whether a successful update has broken something vs. a corrupted update is at fault is a matter of experience and not something I could easily work out?
I'll hold off adding any more posts unless the problem recurs, in which case I'll either post here, or find a more appropriate forum if I can work out what the issue is.
I can vouch for NVIDIA Gpu taking whatever it can...I get a couple of hours battery life on this Workhorse of mine . But, I don't travel with this (got a Chromebook 10.4 inch screen for that) it's used for my songwriting and band work. Why I still dual boot till I get it down.
Sorry not trying to stray from subject. But it stays on a desktop or table in the den. So as @FrenchPress stated I pay little attention to battery life... I'm looking for performance so I use NVIDIA no matter
As @StarTreker stated the cool thing is as easy (or should be ) to fix via his walk.
So am I understanding correctly, you now have an approximate maximum battery percentage, to last up to 5-hours on a fully charged battery now? If this is true, that is not bad! Thats enough time to watch 2 movies, or play a heck of a lot of rounds of solitaire.