I have a few spare solar panels, so I've installed them on my Explorer and Escape, to keep the battery topped.
To do this, I cut a 4ft pair of 3/8" aluminum c-channel sticks and wire tied them to the sides of the flexible
panel, and then wire-tied the sticks to the luggage rack on the roof. Then just run a #16 copper twin lead in
through the back door to a cheap PWM controller, and run that to the drop to the battery. (lookging back, 1/4"
c-channel would probably work a little better)
This keeps the battery in the Explorer topped off so I don't have to remember to start it up every few weeks
to keep it from going dead. (I don't use the Explorer often, it's mainly a transport and Field Day vehicle)
I put the other panel on the Escape in response to a phantom power draw that turned out to be a bad alternator,
but I've also appreciated how it makes for a much stronger crank on a cold Monday morning in the winter.
Now I'm not a very good mechanical engineer, and I've had problems with the panels on both vehicles
"departing unexpectedly" due to wire tie failures. Those just aren't intended for permanent stressful
installations, but I've just kept using them since I don't want to drill any more holes. I just have to
keep an eye on the wire ties and replace them when they start getting brittle. I also install two at each
point, so if one fails, the other is still there. These panels are a pretty strong wind-catch at highway
speeds, so it's pretty stressful on the panel and the wire ties.
I've also been mulling installing my panels up on my roof when not in use for things like Field Day, and wanted
to know how well they'd stand up to permanent outdoor installation. So setting them up on my vehicles has
given me some great experience with how they hold up to exposure to weather. From what I've seen so far, hail
is probably the only thing they won't be able to survive well. We don't get it often, and it's usually less
than pea-size, but even that small size might be able to crack the cells under the thin sheet. The thicker
panels I got most recently (the 4-pounders) might fare better in hail though.
