We are about to put our caravan into outdoor storage having previously stored it at home and want to use a solar panel to keep the battery topped up, mainly for the alarm. We would be looking at putting the panel inside the van, in a window or the sunroof. All advice welcome on whether this would work, what size panel we would need and what else we would need, other than the panel. Thank you.
A panel up to about 15w can be left connected without a controller unit. I would look at something like a 10w bosch panel. Avoid the cheap rubbish on eBay.
I would be very surprised if they didn't, the actual cells have got glass over them anyway. Some older windscreens shield a Sat nav signal, perhaps that's what your thinking of.
No problem using it through the plastic window. I rest mine on the lower window catch and then half pull up the blind to hold it in place.
My mistake was to buy a small one (which works admirably ) and then had to buy a bigger one later. So my advice would be to get the largest you can afford in the first place.
Daves1