Well, at the time when I was buying, I was only looking to buy 1 panel at 250w. Since they were so cheap, I bumped up my system to 500w. At that time, I wasn't even planning on putting solar on my other RV, but I figured, "At this price, I'd better just buy it" and so I did. I have since installed it on one of my other RVs (another identical 500w system).
I will likely add a 3rd lead acid battery giving me 300AH. I think the 500w of total solar power I have will be more than enough to keep them charged. I don't really boondock too much, so I don't really even feel like I need 300AH worth of batteries. But I do have a 2000w pure sine wave inverter and I want to be able to run the microwave from it. I believe it will pull ~150amps at 12v which is too much for just 2 lead acid batteries but I hope 3 will be able to handle the draw.
You can look on craigslist or FB marketplace and find great deals on used solar panels for cheap. Just test them prior to buying. That makes for some very inexpensive solar systems. I think the panels will outlive the duration that most will be holding onto their RVs.
Happy Camping!
-Chris
