Have recently upgraded from a camper trailer to a small caravan - jayco penguin, and need guidance regarding using solar panels. Many people spoken to in the business world give various views and being new at the game I get flustered. The van is set up with battery and a weird circular switch  under bed with positions for 1 / 1 & 2 / 2 / 0 which means little to me at this stage, and what I believe is an inverter, and  on the outside a meter showing charge in battery. On the outside of van a circular plughole which I assume is where panel lead is connected. We have shopped around for a panel but are not sure what we should buy but we want to keep the price reasonable. We have been told 80 watt is good enough, other people suggest higher and some even suggest two batteries. An Anderson plug has been mentioned so what is the plug already fitted. Have any of you panel users any advice to help us clear up our confusion, if so we would love to hear from you - waiting in anticipation