I've seen @pauciflora's other post and thought I'd add my bit in this thread for consistency.
We've got a V90CC and also 2x Land Cruisers that have been set up to run our Dometic fridge for travelling.
In the Land Cruisers I use a Tactix toolbox that I built up some years ago around a 120 amp hour AGM battery, with a direct alternator fed DC-DC charge controller (+ solar input). This works great in most scenarios that I use those in, but there are times where I need more space in the back, and this applies particularly in the Volvo.... by the time we've got a 35 litre fridge, the detritus associated with a 5 month old, and potentially the 2 dogs, we are a bit tight on space...
To solve that, I got a Bluetti LiPo AC2A (which appears to be discontinued now):
https://www.bluettipower.com.au/products/ac2a-portable-power-station, and added a 12V car cable (as well as a solar cable that it comes with).
This ran my fridge (on 12V) quite nicely the other weekend with some solar panel top up from my knackered panels (I need to get some new ones) including over night,
I'd look at something like this as a bigger battery pack, and for not a lot more, as I think on something only a bit heavier than my little fridge would probably draw my AC2A down too much:
https://www.bluettipower.com.au/products/bluetti-ac50b-portable-power-station
The reason I went with Bluetti is that they had a nicer warranty, weren't Kings, and were open in that they are straight out of Shenzen on their user manuals - and have a 5 year warranty on their gear. The fit and finish of everything is very nice; the connecting cables for charging has nice heat shrink at the end of the main cable, and it just feels nice. The app is easy to use to monitor the box as well, particularly useful when I have the box in the back of the ute and can't see what is going on.
In the Land Cruisers, I have Anderson plugs to the rear for the direct alternator charge, and I just connect an Anderson to 12V aux socket that then plugs the Bluetti into charge there; in the Volvo I'll use the rear socket, but disconnect it when not in use - although the Bluetti box does have a low voltage cut off.
