Jayco Eagle 12vdc Off Grid Setup?

[Jayco MN]

Hey everyone. Just purchased my first TT, a Jayco Eagle 30'. I am trying to get it set up for off grid use to live in this summer while we finish our off grid house we are building. I have a few questions concerning the 12vdc system.

First thing is that I am planning to add two 6V 225amp batteries, that I had hoped would be charged by solar panels and by plugging the 30 amp shore line to the generator. However what I have found is that the battery location is at the tongue and that the 12vcd converter / charger is about 20' from this location towards the back. Seems like I am going to have a lot of line loss that far away.

The wire going between the converter and the battery is only 10ga which seems way to small as the converter is a 45amp. For a 20ft run at 45amps some charts show 10ga and others up to 4ga. So is the 10ga fine or do I need to try to upgrade the wire to a larger size?

Next I want to add an inverter to the system so we can use the 120vac receptacles for a few items. Here again it seems like a poor setup with the battery up front and all the electronics in the back as there is around a 20' run between them.

It would be more convenient to add the inverter back where the distribution box and converter are, but the line loss between the inverter and the battery bank is Huge being that far away. The other option is to add the inverter in the battery box and run a new 12/2 Romex line back to the breaker box carrying 120vdc thus negating the dc line loss.

Next there is the issue of feeding power into the 120vac system via the inverter and then the converter using that power to feed back into the 12vdc battery system creating a parasitic load. This could be dealt with by simply unplugging it when the inverter is on, but if I forget then the batteries will get zapped very quickly.

One last thing is that I want to add a few hundred watts of solar panels to the system for the main charging of the batteries. This is simple compared to the rest of the above, but it brings back the question about the location of the batteries to the rest of the system.

Why in the world did they put the batteries so far from the rest of the electrical system? Should I bypass the current battery location and build a box to contain the batteries / inverter next to the TT?

I am really at a loss for the convoluted set up I have here. Any help as soon as possible would be gratefully appreciated as I am moving into this TT next week with my wife and two small children.

Thanks
Dave

[ddrueckh]

For my solar system, I mounted the controller in the front pass through storage. I then ran a line for my battery monitor under the trailer and came up in one of the kitchen cabinets. I think that mounting the controller in the front pass through is how most do it. You want the controller to be as close to the batteries as possible. Make sure to use heavy gauge wire for everything.

If installing an inverter, I would also mount it in the pass through storage and then run a wire back to the breaker box. When running the inverter, you should be able to turn off the converter to make sure it isn't trying to charge the batteries.

Sounds like you are doing a lot of planning and research. Great job. That will insure that you have a good functioning system. Good luck and keep us updated on what you decide to do.

[Mustang65]

Originally Posted by Jayco MN

First thing is that I am planning to add two 6V 225amp batteries, that I had hoped would be charged by solar panels and by plugging the 30 amp shore line to the generator. However what I have found is that the battery location is at the tongue and that the 12vcd converter / charger is about 20' from this location towards the back. Seems like I am going to have a lot of line loss that far away.
The battery location on the tongue is no big issue. Does your TT have a storage area up front by the tongue? You can mount your SOLAR Charge controller in there along with your inverter. That is close enough to the batteries. The long wire run will be between the SOLAR panels and the SOLAR charge controller, since this leg is a higher voltage there is less of a line loss.

The wire going between the converter and the battery is only 10ga which seems way to small as the converter is a 45amp. For a 20ft run at 45amps some charts show 10ga and others up to 4ga. So is the 10ga fine or do I need to try to upgrade the wire to a larger size?

JAYCO puts in the bare minimum wire size for $$$$ reasons. You can upgrade your wire run from the TT's battery charge controller to the batteries to an 8 or 4AWG wire size, but I think you will be ok with what you have, as the SOLAR will be doing the bulk of your daily battery charging.

Next I want to add an inverter to the system so we can use the 120vac receptacles for a few items. Here again it seems like a poor setup with the battery up front and all the electronics in the back as there is around a 20' run between them.

If you have the front storage area you are in GREAT shape. Just mount the inverter in there next to the SOLAR Charge Controller. If you decide to wire your inverter so that all your interior outlets have 110VAC, you will need to put the TT's Battery Charge controller on its own breaker, so that the inverter is not sending 110VAC to the TT's charge controller while using the inverter. Easy set up with either an Automatic Transfer switch (about $80) or you can do it manually like mine. See my solar album link below... ALSO we have an "RVing with SOLAR" group" that may have answers to your questions.

It would be more convenient to add the inverter back where the distribution box and converter are, but the line loss between the inverter and the battery bank is Huge being that far away. The other option is to add the inverter in the battery box and run a new 12/2 Romex line back to the breaker box carrying 120vdc thus negating the dc line loss.

I ran a 12/3 Romex to the back storage area where my shore power comes in and put in 2 RV oulets which you select either 1. Shore-power or 2. Inverter (the automatic transfer switch would go here) The inverter needs to be AS CLOSE TO THE BATTERIES AS POSSIBLE.

Next there is the issue of feeding power into the 120vac system via the inverter and then the converter using that power to feed back into the 12vdc battery system creating a parasitic load. This could be dealt with by simply unplugging it when the inverter is on, but if I forget then the batteries will get zapped very quickly.

Put the TT's Battery Charge controller on it own AC breaker, very easy to do. If your solar setup is large enough to keep the batteries FULLY charged then you do not need to use the TT's charge controler. Mine has not been turned on since we went SOLAR

One last thing is that I want to add a few hundred watts of solar panels to the system for the main charging of the batteries. This is simple compared to the rest of the above, but it brings back the question about the location of the batteries to the rest of the system.

As I mentionded earlier there is not much line loss if you use the proper size wire because the panels are the higher voltage part of the circuit. A good rule of thumb is if you have 225Ah batteries (2 6VDC in series), 10% of your batteries Ah (22.5) is the proper amount of current you would like to have (incase of more than one cloudy/rainy day) as they should give you enough to get you through them.

Why in the world did they put the batteries so far from the rest of the electrical system? Should I bypass the current battery location and build a box to contain the batteries / inverter next to the TT?

Leave them where they are located!!

I am really at a loss for the convoluted set up I have here. Any help as soon as possible would be gratefully appreciated as I am moving into this TT next week with my wife and two small children.

Since you have a generator.. I would start with the batteries, add an inverter and get the solar...

Thanks
Dave

I am sure you will get additional assistance regarding SOLAR as there are a lot of us here using solar.

Just my thoughts,

Don

JOF RVing with SOLAR

[Jmooney]

here is a schematic of what I did in my 5er. Similar configuration with batteries up front and converter mid cabin. I expanded my batteries, added an inverter for the entertainment system and 200 watts solar on the roof.



Also some more pics in my profile

[Jmooney]

may not be pretty, but very functional