Jayco Eagle 12vdc Off Grid Setup?

**You will also want to make sure your water heater electric mode is off, and the fridge is set to GAS, not auto select. Or turn the breakers off for them.

Looks like there is pass through storage at the front of the TT? This would work great for the solar controller and inverter location and is exactly how I did it in our TT. I drilled a hole in the floor of the pass thru storage for wires which then lead out the front of the TT to the batteries on the tongue. I've got about 5' of cable length between the batteries and controller & inverter.

Wire gauge and distance doesn't matter too much between the panels and the controller because your controller is going to prevent the batteries from seeing the peak panel voltage anyway. Still get as fat as possible, but don't worry about it as much as between the controller and batteries as has been mentioned several times already. If your controller has separate voltage sense wires, it will compensate for the voltage drop on the charging lines. But I think it's still wise to go as fat as possible so you know you aren't creating a bottleneck.

The easiest way to wire up the inverter to power all of the 120V AC outlets is to just plug your shore power cable into an inverter AC outlet. AS you've pointed out, the converter must be turned off.

You are correct that the converter is far from the batteries and there is quite a bit of voltage drop due to that, but who cares once you have solar doing most of the work. My converter has been switched off at the breaker by default and I almost never use it.

Chandalen wrote:
I prefer 6v batteries in series to make 12v. There are no true deep cycle 12v batteries.

I have several of these. They do great above 12.5v, but below that they go down quickly.

Lots of questions, and a lot of these topics are covered on this site (recently)

A lot is personal preference. I prefer 6v batteries in series to make 12v. There are no true deep cycle 12v batteries.

Some people get confused here so I’ll clarify, you can add voltage or add current, not both. Meaning you can have two 6v 200 amp batteries, make them a 12v (series) battery and it will still be 200 amps. OR you can have two 6v batteries (parallel) and they will be 6v and 400 amps.

You could rewire from the converter to the batteries and get some voltage back, but I'm not sure its worth it.

Important distances are Solar panels to the solar controller. Solar controller to the batteries. Inverter from the batteries. The lines need to be as short, thick, and equal in length as possible. Also figure max current draw and have lines (and a fuse) appropriately sized. YOU CAN double up wires to have a higher gauge but lower voltage loss (ie two 10ga wires per pole vs one 10ga per pole will have less of a voltage loss)

The distance from the inverter to the 120 plugs is not (usually) a factor, unless a high amp draw device is being used (like an AC). Do NOT place an inverter next to or in with the batteries. This is a bad practice.

The inverter you get should be a PURE Sine Wave type. A Modified (standard off the shelf at Harbour Freight or Walmart) Sine wave will easily fry a lot of electronics, chargers!!!! It also causes the devices on it to use more power than they would off house power or a PSW inverter.

Most PSW inverters have a remote on/off remote included or available separately. This allows the PSW to be installed wherever its closest to the batteries, but you have the ease of a radially available on/off switch.

Keep the length from the batteries to the inverter SHORT. 3’ about is ideal. Be ready to use some thick cable if you are using a large inverter. (I have two 1/0 gauge per pole, each fused)
Have a fuse close to the batteries between them and the inverter.

For wiring the inverter in to the camper 120 lines. If this is something you will do a lot, then leave the converters breaker off, unless you need it on shore power, then its easier to make sure the inverter is not connected.

There are a lot of ways to do this, some are unsafe. (Suicide cords)

Solar… You need to decide how many panels you want. This is a personal preference but I love Renogy panels, great company and support.

You will need a charge controller. Get a PWM –not- an MPPT type. (insert debate here) MPPT is simply not worth it, and will likely perform worse than an PWM for small solar systems. (less than 800w in panels) This gets worse if the temperature is high in your area (>90 degrees). (do some research on the pro’s and con’s of MPPT and PWM, as well as PWM vs MPPT)

You are of course limited by roof space. Look at the roof for ideal placement, and try to either keep the wire lengths to a minimum or run lower gauge wire. Think about how shadows would be cast over the panels from the vents / AC/ skylights on your roof. Try to avoid them if you can.

I like Morning Star controllers. They are generally fully customizable for voltages, and perform very well. Think about getting a controller that allows for further expansion. A 15amp controller is cheap, but that’s only two or three solar panels. A good controller will have a temperature sensor (option), battery voltage sense (option), and very configurable voltage set points. The TS-45 allows about everything to be programed by your computer to the 0.01 volt. I also like the ability to set the LED indicator lights to change colours based on battery sense voltages.

The Voltage sense option would probably get rid of Canadian's volt loss due to distance. The controller will send a higher voltage to make up for that loss with the battery voltage sense wires attached.

Hope this helps!

Welcome to Solar Dave!

You seem to have a pretty good handle on your new rig's problems and even the solutions.

Yes, 20 feet is a long run. I have a similar problem in our 32' DP believe it or not. The batteries on one side, the converter a good distance away though at least it was connected with #6 cable.

That converter is now gone, replaced with a Xantrex Prosine 2.0, a pure sinewave inverter with a 100 Amp charger. The inverter is now in a compartment next to the battery drawers, about 3 feet of 3/0 cable.

Our solar arrangement however is another story. I wanted the controller display in the galley where I could watch it. There is no other location that would be suitable. In any case it was going to be a difficult and long run from wherever I placed the controller to the batteries so I still have that long run. I used the existing #6 for most of it, adding about 8 feet of # 10.

At 20 Amps I have a full one volt drop between the controller output and the battery terminals, which means that the controller starts to taper the current way too soon, as it thinks the batteries are at 14.8 when they are in fact only at 13.8V. I am probably going to have to get a new controller; either one with a remote battery voltage sense or one that I can place in the battery compartment (verrrry tight for space) and use a remote control panel in the galley.

For your setup I would recommend that you either mover the charger/converter closer to the batteries or get MUCH larger feed lines.

Both your inverter and solar charger need to be much closer to the batteries, keeping the DC lines as large and short as possible.

Keep in mind that the voltage drop in the wires between the solar panels and the controller in much less critical than that between the controller and the batteries. In the former case, voltage drop may cost you a bit of over all power but the latter (high loss to the batteries) will really increase the time to get to a full charge. Voltage drop (loss) will decrease with current but in my case, the charging can be so slow that battery voltage often doesn't reach 14.8 long enough to give a full charge before the sun goes down.

You might also consider doing what I did, buy a good pure sinewave inverter with a decent charger built in and locate it close to the batteries. You could then just ignore or disconnect the converter.

You won't have the same problem that I do with the solar controller since you will be buying one anyway and can locate at the batteries. If you want to see what the controller is doing, get one with a remote display (most have them) that you can place where convenient.

You could leave the batteries where they are and minimize line loss by getting 2-12v batteries, and running them in series @ 24v. Then of course you'll need a 24v inverter, which are not hard to find.

If you want the inverter in the battery box, which is never recommended, it's best to get AGM batteries to not eliminate, but severely limit any outgassing.

I doubt you'd forget to turn off the converter as long as you look at your system voltmeter now and then. It would be telling you quickly that your battery voltage is dropping, fast.

Solar panels can also be connected in series to up the voltage to limit line loss.