I know this is somewhat of an older thread but I have the same question. 90% of the time the vehicle charging system is just fine for what we do. Once in a while we stay somewhere for a number of days. Having solar would be nice for that. I was thinking of a portable system because it is not needed much. Seems that most seem to think a permanently installed system is still the way to go even if you park in the shade. I would think the output would be much lower in the shade but maybe there is still enough to make a difference. Is it worth doing a 100w panel on the roof to start with?
My other concern is wind resistance. I think I would use solid panels raised off of the roof top with some kind of a rack. Does this take a bite out of MPG? I would think it would do so at least a little. I already have a fan on the roof so maybe it is not that much.
My loads are not that much. I have a fridge (~4A) and the roof vent fan (~2A at most) plus charging phones (~4A at most) and a few LED lights and other small fans.
Thx
I think having to get a solar panel out would be a pain. I wouldn't want to store one. Kind of a big clunky thing to store. And you won't really save any money over mounting it. Will you get more sun if you can direct it to the sun? Yes but you won't get sun if it isn't out. I think a mounted panel will do way better than a panel that you can tilt toward the sun because the mounted panel is always out. And you'll need to constantly move the portable panel to get the best angles for the sun.
I don't think the panels will hurt your gas mileage especially if they're mounted further back. You can always put a little fairing on the front. I'd go with 200 watts minimum. You can get the renogy eclipse panels if you're worried about space.
Solar is such an easy solution and its inexpensive as well. I'd say dollar for dollar is some of the best money you'll spend on the van. A fridge and fan (running at 100%) could use quite a bit of amp hours on a day. Even though you may be driving everyday, will you be driving at least a couple of hours? Anyone want to chime in on how long it would take to charge up 200ah of batteries at 50% from the alternator? Having all three systems, no way I'd rely on my driving to charge. I'd constantly be thinking about my batteries.
Ultimately I gave you a long winded response to say the same thing KOV said above. Don't waste your money on portable solar. There's a reason you don't see anyone using it.
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