I use dual 6V batteries and have since we bought out RPod 179 in December, 2015. We can get multiple nights boondocking. Now, if you are thinking that the batteries will run the AC, forget about it. That isn't going to happen unless you have a massive solar bank and lots of LiFePo4 batteries or a good generator. However, you can run the lights, water pump, and Fantastic/MaxxAir fan on battery for multiple nights if you plan on running the refrigerator and water heater on propane. The furnace can also be run, but since it draws more, you would not get as many nights with it running. Also, we found that dual 6V batteries will also not power the refrigerator overnight so plan on using propane for it if you don't have shore power.

Full hook-ups will allow you to run everything on electricity with multiple items at the same time such as the AC and Convection Microwave or water heater.

That's a relief. I believe I am going to go with 2 golf cart batteries. 6 volt wired in series. I would like to be able to boondock for 1 or 2 nights. It would be just my wife and myself. Probably just in the heat of summer for my wife. We will see. Our first trip is going to be at French Creek State Park in PA. Full hook ups.  We will drive from there an back to Philly to see the Cherry blossoms. I still haven't run any of the systems yet. I'll have to learn how to do that.

If you wanted to route separate heavy cabling to the trailer battery from the tow vehicle (when I say heavy I'm taking about maybe 2/0 conductors) then yes the larger alt could improve things.  But you are likely to find you're just fine with what you already have. 

 There should be a circuit breaker or fuse installed in the trailer connector charging circuit somewhere near the two vehicle battery, that would tell you the max charge current you could potentially get. Those are usually around 30 amps, you will always get less than that. The fridge on 12V takes about 11A so you can see that it is a very significant load. 

Originally posted by GlueGuy So it behooves you to know if and how much current your particular tow vehicle can provide to the trailer. Ours works fine, others have reported varying degrees of success.

Can I find that out with the battery off?

Some tow vehicles deliver more amps to the Bargman than others.  Some will deliver enough to charge the Pod battery, even if you have the fridge on 12v.  Many won't.  You could end up at your destination with hot food and a dead trailer battery.  This is one reason a lot of people travel with the fridge on propane.

TT, stepping back now

Is there any concern about having 142 pounds of battery up front? I am looking at interstate bateries at 71 pounds each.

https://www.interstatebatteries.com/products/2400utl?productLine=golf-car&subcategoryKey=&ignorecategoryid=true

Thanks again. I put it on my amazon list of things to buy.

I hear a lot about using golf cart batteries. An old timer at the nursing home told me he used 2 6 volt batteries. The old timers usually know best I think. He also told me to cook ground hog in a pressure cooker. I'll have to try both.

But, its always best to wire batteries in series not parallel. Why? Because if you wire them in series the same current is alwas flowing through both so they are guaranteed to alwyaybe charged and discharged identically. In parallel, one battery (the one with lower internal resistance) will always be cycling more than the other. No two batteries are exactly the same due to manufacturing varaiation, so this will happen.

If you have two of them, they will have twice the capacity. Just as if you had two 12 volt batteries. 

HOWEVER... the 6V GC (AKA "Golf Cart") batteries will be less expensive than the equivalent capacity 12V battery. Also, the 6V GC batteries come in slightly larger sizes (like 240 amp-hour).

Thanks podwerkz, That is a great help. I see the difference now. The deep cycle is 10 bucks cheaper too $