I have a Pure Freedom 500 litre system installed in the van but find it easier to run the hose from my static system because I find it less strain on the battery and fills quicker,I can have the mains running into the back of the van via portholes but I need the battery running for the booster pump within the van as my preasure is low,takes about four hours to fill with a 4040 membrane,it is easier to leave on over night etc. but can fill from my static system within ten minutes,I just have to keep an eye on it so it does'nt overflow but when I do use through van system it automatically switches off when full as the auto shut off stops the pump when the small ball cock thingy is forced up from the water,if I'm going out for a while I stick it through the van!