what to do about electrical systme when storing?

If I am going to be unplugged from shore power for very long, I have found it helpful to pull the main fuse on the 12V system to stop the parasitic drains. However, the battery will still slowly self-discharge even without anything drawing on it. That is why it is still good practice to plug it into shore power for a day or two each month, if you're going this route.

A decent multistage converter will make this procedure unnecessary, though, by just leaving the TT plugged in.