It's worth having a backpack and 25 ltr water barrels as a back up for when your van and system is off the road.
yes thats definitly something what need to think of,ive never seen backpacks and trolleys,is it possible to produce pure water from these?
Well I have a static RO set-up in the garage so I can still produce pure water if my van is off the road.
At a push I suppose for a short while you could get away with using just a DI vessel if you cannot use RO or see if you could buy pure water from another window cleaner in the short term.
I would recommend getting a backpack though because they don't take up a lot of room in a vehicle and at a push you could still work from a car if you really needed to.
For the sake of spending £150 on a backpack and a few water barrels its well worth it I reckon.