I am adding a 12 volt system to my van which only has 12 volt on the internal 2 roof lights (with 240 lights of course) and the fridge which can run12v  when the van is plugged into the car.

I did some calculations on usage and so far I have now got 240 AH of AGM battery power, and 120W portable solar panels. With a 600W inverter.   The fridge will run on gas, leaving 12 volt for to run things like TV, media centre, laptop, 12 volt lights phone &camera charger, fan,and electric blanket for when it is cold.      Have also got 75ah in the boot of the vehicle running off a 50amp charge system from the front car battery. Van can plug into this as well through an anderson plug.

Does this all seem about right in real life? Have yet to try it out as I am working out the best placement for it all. Any advice appreciated.

Cheers, John