Using Xantrex solar max flexible panels as portables?

The 7-pin is an easy method, and interesting. The wire gauge (or lack of it) would be the only issue.
Look up "Anderson Plug" on ebay. Get a big'ish one and use heavy gauge wire. 14 g or 12g at least, 8 or 10 better, but that gets hard to use, and keep the wire distance to the battery as short as possible. Anderson plug is popular, but depending on your abilitys there might be easier-to-attach plugs out there that are easier to attach the wire to the plug. The Anderson plug can be soldered, and is how I do mine. I guess it could be crimped too.

There have been questions before about how to connect a portable to the RV's battery

Not what the OP wants, but posting it to draw attention to the adapter for connecting the solar controller to the RV's 7-pin cord. (scroll down)It seems this adapter is also available with other portable kits these days. (not always the best way to do this if there is much voltage drop, but ok otherwise)

Some years ago when I first got solar, time2roll suggested using the 7-pin, and I tried it out with a DIY adapter using just two wires and it worked. (Limited by wire gauge vs length of course) So interesting to see "real ones" available now.

http://www.wegosolar.com/products.php?product=180W-Folding-Solar-Panel-Kit-

I use one of these panels as a portable.
https://www.windynation.com/Monocrystalline-Solar-Panels
Lives under my mattress when not used. I wired in a pigtail off the controller to the outside storage that this panel plugs into when needed. I have the same type of panel mounted on the roof. Most of the time the roof panel takes care of my power needs, but occasionally being able to have a portable is a nice option to have.
I do know these flexible panels get reviews of not being as durable as glass panels, but I haven't had any issues with mine so I'm happy with my setup.

Other post said $500, which is insanely pricey.
Ebay you can get panels for less than one Dollar per watt. 100 watt panel is about $80 shipped.

The issue with the flexible panels is that they are not durable. They are meant to flex once! Once when you install them onto a curved surface. They are not meant to flex all the time. Flexing will eventually break the internal parts.

The flexible panels typically have a 2-3 year warranty while the glass panels might have a much longer warranty, that tells you a lot.

There are times when you just have to have the flexible panels for your install, otherwise I would always recommend the glass panels.

I had a gel-coat fiberglass camper with a curved roof and did not want to drill into it to mount panels and did not want flat panels poking up above the curve, so taped the flexible panels up there. On my camper with a flat roof I use the glass panels as they are superior.
Be careful as the panels need air to circulate under them for cooling. I put corrugated plastic under the panels so the flutes would let air circulate. The panels will fry in the sun otherwise and also cook your roof.

Portable panels are great as you can park in the shade but put the panels in the sun. Consider just adding more glass panels to the roof so you can still park in the shade and generate enough power still.
I dont know your situation though.

Great info about the Dokio -- thanks to both of you for bringing that up.

Lwiddis is exactly right -- these are very expensive units on a "dollars per watt" basis. But not only do I have almost no roof space -- we usually park the trailer in the shade, so a high-output portable is a very attractive idea.

If I can only convince my Budget Director . . . . ;)

We have a 320W Dokio folder, and it works great!! About 20# max, fairly decent build, and puts out pretty close to expected specs. 22.5 V open circuit and 16-18 A shorted. Not too clumsy closed, but is large when open and only used in decent conditions. I have made a mounting system for the roof of the Excursion to flat mount. Not the best, but secure, and easily removable when needing to use the vehicle. Also, made a couple of 12 awg extensions with SAE connectors to use for positioning (kit looks like 16 ga, MAYBE 14 ga!!) Controller is a 20A PWM that actually is fairly useable!! Has a couple of adjustments for voltages and easy use. I'm happy!!! I'm sure time will tell how it holds up, but good unit at a good price for the power output!!

Wow. $500 for 100 solar watts. I'm out! But then again I've got more roof space than profdant does.

They appear to be fairly pricey at $500 for 100 watts including a 30 amp charge controller.

https://www.amazon.com/Xantrex-781-0100-01-783-0100-01-Charging-Kit-100W/dp/B07QZFC7H6/ref=sr_1_1?dchild=1&keywords=xantrex+solar&qid=1587137003&sr=8-1

size 50.4 x 29.1 x 5.1 inches weight 4 lbs.

DOKIO makes some lightweight folding panels. Here's some available on Amazon:

DOKIO portable panels

ISTR a thread on that back when. He had a hanger for one that hung above another somehow IIRC.

ISTR he held the bottoms out with tent pegs, but all too vague. Somebody might remember that.