I have a Resmed Airsense and I purchased a 12 volt power supply for it and installed a 12 volt power outlet next to our bed.  If I run it without the vaporizer it doesn’t use that much power.

Beyond that, you could plug in a portable 100 Watt solar panel with integrated controller to your Zamp connector.  You will need a polarity reverser at the Zamp connector and MC4 connectors/adapters (some minor wiring required to install MC4 connectors).  

But, it is good to be realisitic about what can be run from a small solar module. A 10 watt module will only produce about 0.5 amp under full sun conditions, or about 2-3 amphours a day on a good day. That likely won't even maintain an rPod's battery supplying the typical parasitic loads in the trailer over the long term. 

OTOH, if you start out with a fully charged battery and are conservative you can go many days without needing to recharge at all, in which case having a charging source while boondocking might be uneccesary. 

It depends on what you want to be able to run in your trailer,the led lights are usually the smallest load. The furnace, fantastic fan, TV, etc are much more significant. 

The "solar generator" you sent is a combination of a battery and a dc to ac inverter so it can provide 120Vac to run things like the CPAP. Its a small battery though, only 288 watt hours compared to about 2000 watt hours if you have dual batteries on your rPod. I get your concern about keeping the power sources separate to start with so you don't run out of juice for the cpap. it provides you some flexibilty too. 

But, how long the little "solar generator" battery would run a cpap will depend on the cpap of course. If your two friends have the same cpap then the 2-3 days might be a good number but I, like GlueGuy, am a little skeptical as cpaps can use a lot of power. It apparently does have a cigarette lighter charger too so in a pinch you could run your tow vehicle and plug it in there to recharge a bit. 

As to your idea of using the same solar module kit to charge both the "solar generator" and the rPod batteries, I looked at the Amazon Q&A it is looks like the "solar generator" will take a 1V solar kit up to 100 watts. So, that should be possible if you make up the right connector to plug the solar modules into the solar generator. The solar generator manufacturer says it uses an MC4 connector so if you get the solar generator you should also get the "solar panel cable" kit that is listed. The solar kit that you can buy with the "sola sgenerator" is only 60 watts so a little on the small side for the rpod. 

if you do share a solar module kit between the rpod and the solar generator/ cpap then beware you will be reducing the amount of recharging each will get, so be judicious in how much power you use and/or keep your first trip or two with no hookups short so you don't run out of power.  

I do not understand JHoller's replies. (Not sure what extension you are referring to and, honestly, am not sure what an inverter is or why you think I need one.)

I do know that the solar generator is not a generator at all (thus the quote marks). I resisted the urge to call it a battery in my post because that would have made confusion between it and the camper batteries in my questions and your replies. I have two camper batteries already a 6volt and a 12volt (I think, though I do not yet know what that means). Electricity, man. This stuff is tough.

I also know I *could* just charge the camper batteries and plug the CPAP in, but my travelling buddy is not as excited about dry camping as I am and the way to convince him is the secure a dedicated power source for the CPAP. That way while we are learning power management we are not risking that thing not running through the night (that particular battery pack and solar set up was recommended by someone who uses a CPAP and gets 2-3 nights from a charge.

Anyway...lots to think ab out and you guys have been generous and helpful.

That so-called "solar generator" is just a relatively small battery (approximately 24 amp-hour capacity) with an integral inverter and solar charge controller. If you have the typical 12V battery in your R-pod, that will have around 4X the energy storage (assuming a 100 amp-hour battery is "typical").

So what you would be getting from it are two things: (1) the inverter, and (2) solar charge controller. Reading the information about the unit, it is, indeed, a 12V system.

You would still need solar panels.

If your CPAP runs on 12V, you would not necessarily need the inverter, but if it needs 120VAC, then you would need an inverter. I would rather have a separate inverter than have to maintain an extra little battery, but that's just me.

If you get a solar setup with panels and a controller, you would be able to just use the battery (or batteries) already on your R-pod. I would recommend a 2-battery installation. Get another 12V battery if that's what you have now, or if the battery in your R-pod is near the end of its useful life, get a pair of 6V GC batteries. Your CPAP will most likely consume more power than the little battery in the so-called "solar generator" can deal with.

Should I assume from what you said that "modules rated for 12 volt charging" are different from ones rated for a "solar generator"?

Here's what I'm trying to accomplish: the "solar generator" will be a dedicated source for dry camping with a CPAP. I will buy one with a compatible portable solar panel. I was hoping to get double duty from the portable panels being able to use them on alternative days to charge the generator and to top off the camper batteries. 

This is what has been recommended to me (though I am not wedded to this set up): https://www.amazon.com/gp/product/B01IW408R0/ref=ox_sc_saved_title_4?smid=ARF0LRVVRSDPX&psc=1

Further thoughts and opinions appreciated.

The zamp "wired for solar" just means that there is a connector on the side of your trailer that has wires from it that run to your trailer battery. You can connect a zamp system or one you make up yourself to that connector or connect any other solar system directly to your battery bypassing that connector. Doesn't matter. Either way you will need solar modules rated for 12V battery charging and a charge controller so you don't overcharge your trailer battery. 

Since you want to make a portable system I'd suggest you look at the ones on Amazon like say this one which comes with the charge controller and can clip right to your battery. 

It should have everything you need except the cable from the trailer to the solar kit is only 10 ft so you will pronbably want to extend that. If you do ask and we'll give you some suggestions what wire to get for that. 

On the "solar generator", what do you plan to use that for? I would suggest that you don't try to connect that to your portable solar or trailer battery system.

My 172 is factory  "wired for solar" with a zamp outlet (whatever all that means). I want to buy panels to charge the batteries while dry camping but I am also looking to buy a lithium "solar generator" (I know its not really a generator). I'm wondering about compatibility between the zamp system and various portable solar panels. Are there more things I need?  Are these all interchangeable with the appropriate cords? If you could please answer in normal English instead of electrical engineer-ese I'd appreciate it.

Thanks for your wisdom and experience.

Julie