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I'll pipe in to call attention to my hope that you're not planning on a "solar powered RV" situation.

It would be hard for solar panels to break even with the energy requirements of the added weight they bring.

You'd probably be looking at weeks to charge up your batteries with them. This isn't "park for a couple days to recharge my batteries, then drive 2 hours down the road" kind of thing.

Very rough ballpark, I'd say you'd be using 1000-2000kwh per mile of range when towing a trailer (versus 250-350-ish kwh per mile in a small, light car). The Jeep itself, hmm.. maybe 600 or so? If it's beefier like you plan, well, a van uses around 800-1000kwh/mile. Let's say you can get away with 600kwh/mile at 60mph (not 80, which will be like 1000). You want 120 miles of range. 600wh/mile x 120 miles = you'll need a 72kwh battery pack to do that. That's really, really heavy, and really bulky. Around 1000 lbs.

While towing, let's say 1500kwh/mile. ~48 miles. I dunno if you can even hop to the next campground with that kind of range.

Then, how much solar are you putting on your trailer roof? Being generous and saying 1000 watts? How many peak solar hours are there on an average day in your area? Maybe 3-5? Let's say 4. 4000 watthours per day.

You've got a 72,000 watt-hour pack, so, 18 days to fully recharge an empty pack. Which then gets you 48 miles down the road. Or, rephrased another way, 2.7 miles per day.

A far better use of money is to just buy a large gasoline generator, keep it in the trailer, and use that to add miles when you happen to be travelling with the trailer. Even a little minimal 2000 watt honda generator could be run 24/7 and at least get you charged back up in a day and a half.

Or, put another way since you say you want to use solar to help add range while driving... 1000 watts of solar, let's say you're in peak sunlight when driving. You're using 1500 watt-hours per mile. That's 90,000 watts to maintain speed. You're bringing in 1000 watts with your solar. Your solar is contributing just over 1% of your power requirements to maintain that speed. Is that significant enough to bother with? And that's noon sun. In morning or afternoon you're looking at maybe 1/400th of your power requirements. Might as well get out and push.

Every few months someone is dead set on an EV motorhome, or solar EV RV, and, I've never even seen anyone get started. I saw on Youtube once, one family built a solar EV RV, and they were getting something utterly comical like 12 miles range. They tried to sell it as "Oh it's good to just take your time and enjoy a slower pace of life" but to me, it looked like "Oh my god we spent all this money on this expensive project without thinking it through, and this is hugely disappointing but we can't admit that to ourselves, so, we'll talk about this failure as if it's a different kind of success."

I do want to see someone do it, I really do, but, the cost of hauling that much battery and/or that much solar is literally more than a lifetime of gasoline expenses. It never pays back the cost of building it.
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