Hi y'awll,
Anyone heard of "Bluetti?"
They have a very good range of portable battery units.
Link >
https://www.bluettipower.com.au/
Bit pricey but well worth the $$$'s.
Ref; John Cadogan who does full reviews of these units. (AutoExpert dot com dot au on his YouTube channel.)
The small EB55 unit >
https://www.youtube.com/watch?v=OfW3OxI0OOM
The larger AC200Max one >
https://www.youtube.com/watch?v=xlZkqL9cDXA