Long story short: We have one of those little $100 Chinese mini PCs running 18.04 LTS. ("Wintel Pro" / "Wintel Box") It thinks it has a battery, possibly because it thinks it is a laptop. The "battery" level notifications - that I have tried a million ways to kill - are driving me nuts because I'm trying to use this machine to run a looping slideshow while the workplace is open.
(Update: It wasn't just the battery notifications on the desktop, either. Sometimes it would just shut off randomly. I have a nearly identical model without a desktop and it exhibited random shut-offs until I applied the same fix detailed in my own answer below.)
Related question: Why does Ubuntu power management set a battery as the default power supply on a desktop machine?
This is where someone asked "What is the output of laptop-detect -v?"
It is: We're a laptop (non device ACPI batteries found)
But we are emphatically not a laptop, and we don't want to be a laptop. How can we not be a laptop?
CPU is Intel Atom x5-Z8350. Do let me know if additional information is required. The fault may have nothing to do with Ubuntu but I live in hope Ubuntu might have the tools to fix it.
(Aside: LibreOffice Impress slides run fine, but I would not recommend these machines for high-resolution video playback.)
LSHW output: https://pastebin.com/e5XXp8A0
Also, thank you to @Sri for reminding me that I'd already tried turning off "Notification Popups" and it did as much good as a piece of paper towel against a flood. The "battery" notifications seem to cheerfully disregard this setting - even with notification popups ostensibly OFF, the nonexistent battery still breaks through.
Update: Apparently there is an "axp288" device inside this miniPC, and apparently there is some discussion somewhere on the LKML about this: https://lore.kernel.org/lkml/20190520115247.828904395@linuxfoundation.org/
Is there a way to get this code into my instance of Ubuntu? Would it even do any good? (Maybe it's already there?)
sudo lshw.Despite the model being W8 Pro, it shipped with Windows 10 (probably Home, I don't remember). I don't recall any weirdness with a "battery" there, but I also wasn't using it for long. I have an identical unit at home that is still on W10, and I don't observe this kind of problem.
The 32GB of "ROM" refers to the eMMC memory used for the OS and storage. It is not a lot and it is not fast, but it works.
– Will Matheson Jan 30 '20 at 00:54https://ark.intel.com/content/www/us/en/ark/products/93361/intel-atom-x5-z8350-processor-2m-cache-up-to-1-92-ghz.html
– Will Matheson Feb 12 '20 at 21:26echo - | awk "{printf \"%.1f\", \ $(( \ $(cat /sys/class/power_supply/axp288_fuel_gauge/charge_now) * \ $(cat /sys/class/power_supply/axp288_fuel_gauge/voltage_now) \ )) / 1000000000000 }" ; echo " W "and got "19.5 W"based on this: https://unix.stackexchange.com/a/78437/337130
– Will Matheson Feb 12 '20 at 22:05