Earlier quoted context omitted.
It isn’t necessarily implied, but if this thing is pulling a nominal 30W-40W (assuming considering the 60W PSU) then I don’t know how much use this would be for a portable device, even for RVs. That’s a pretty significant load, even for an amplified antenna, I would have thought?
Did some quick research on a major American car parts retailer's website. The biggest batteries they sell are rated as high as 188Ah (though they use a weird industry-specific unit to say that). Many are closer to 25-50Ah. Definitely enough juice to power a terminal for several hours. This lines up with my personal experiences. I have personally used a car battery to keep a big gaming laptop charged for an entire wee…
For reference 60w is similiar power draw to a Dometic fridge or a laptop.
Also adding a huge heavy battery to a boat is a non-negligible consideration in a lot of cases.