To answer K and I's question (which is relevant to the OP's question, so we are not hijacking), this is a no-name Chinese imitation of a Renogy suitcase. I have it on an extra long, extra heavy cord, to avoid voltage drop. We park the trailer in the shade and try to put the panel in the sun.
When we are in a campground, we lock the panel with an extra long bike cable -- 30 feet! Got it at Harbor Freight. It keeps honest folks honest. A crook with a good bolt cutter could probably steal it easily. Never had a problem, so far.
And this 120 watt setup works for us even in the winter, as long as there is some sunshine. But again, be aware that we are very, very careful about power usage.
So in cold weather, for example, we just dress very warmly instead of running the furnace. We look funny. But if it works for Eskimos, why not for us??
Plus we use a down comforter at night -- the trailer often gets down to about freezing. We sleep like hibernating bears -- much better than at home.
Unlike bears, though, we do have to get up at night to use the bathroom in freezing weather. That is part of the fun, right?? ;)