Best Tips for maintaining a Stored Van

Having had our 2013 caravan slightly dented by a neighbour, (yet again!!) we have decided the time has come to relocated the 'van to a secure storage compound just down the road from us. Very happy with all arrangements, but I was just wondering what advice you would give to best look after the 'van. Whilst store at home we had the electric connected, and hence always a fully charged battery. Obviously this will not be possible in a compound, and the tracker alarm system will pose a slight drain on the battery. I don't want to bring it home and find the mover won't work!! How dou you combat damp? Lots more similar questions so any advice would be welcome.

PS we will be using the 'van on and off through the winter months as we are both retired.

Thanks

Colin