Here is an older document from Resmed about battery requirements, good info. Most batteries on amazon are measured in WH, you can convert to AH with the calculator above and figure out how many hours of use you should be able to get out of a charge. Should be able to get close. Your mileage may vary
https://document.resmed.com/en-us/documents/articles/198103_battery-guide_glo_eng.pdf
Calculator https://footprinthero.com/watt-hours-to-amp-hours-calculator
edit: need to get a DC/DC convertor to plug into cigarette adapter for most efficient usage something like this: https://www.amazon.com/dp/B07P6H994Q/?coliid=I190AAEUPB93CA&colid=2Z0U1F795EW11&psc=1&ref_=lv_ov_lig_dp_it
But they're rated at only 7watts!
Ok, I typed that with a straight face, my 'challenge' for the day is passed!
For anyone else, you do not want to throttle a PC with a weak power supply, and these things will draw more than 7watts and then you're adding the glasses on top.
Once you start looking at 12v systems, you're usually looking at barrel connectors, thanks for pointing that out!
I got lucky, I have a 40 year old plastic case that is a perfect size to fit one of these miniPC's and one of these power banks. I stuck a 12v meter on the front and an Aurga to the side and now it's my 'suitcase'! ROFL! Lasts for almost 2 days!
You can get smaller power banks but, in general, 12v power banks are going to be bigger (than a 5v one) and harder to find. More expensive, too.
It was fun to setup and surprisingly useful but not something that I think a lot of people have much use for. Laptops work well, too, without the customization. They do work great as low power desktop units, tho!
I am a bit jealous! The more you play with these things, the more you find their limits... but they're so cheap! 😋
I saw this one recommended in a youtube video.
https://www.amazon.com/Renogy-72000mAh-Portable-Generator-Technology/dp/B0791WDZTW/