Before buying, check that the roof of your caravan can support the weight of a solar panel as some won't.
Also, a flat panel is less efficient than one that is angled, so it may be worth looking at a portable, folding solar panel.
Solar panels used in this country are not very efficient due to our unreliable sunny weather so make sure you find a panel that will meet your output needs.
I have a 13w folding portable panel that is sufficient to keep my battery topped up over the summer months but I only have 2 small LED lights that run off my 12v battery.
Just some things to consider before you part with your money.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets