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Old 03-27-2016, 08:17 PM   #1
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Cornville , Maine
Join Date: Oct 2015
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Help: Shore (AC) & Batteries

Hey there everyone. Long time follower first time poster. So long story short me and the girlfriend just got a '77 31' Sovereign with the rear bath. Currently interior is gutted and moving on to re-insulating and putting in solar.

Current state of electrical is that everything works fine. Owners manual describes the system as when running on batteries only the DC lights and DC (automobile cigarette lighter style) sockets work for appliances. The manual says that the AC sockets only work when hooked into shore power. There was a converter in the trailer and I guess this was simply to convert shore power to 12V DC to run the lights when plugged in.

Now here's the funny part. My knowledge on electrical systems is very crude. Now, the dilemma:

I want to install solar. But I'm trying to wrap my head around the switching between AC/DC for running lights, outlets, etc...

I understand that if I wire my new batteries into the system the existing 12V DC lights will operate just fine because that is what the 12V batteries will be putting out. Now, I'm also going to wire in an inverter to take that 12V DC power and be able to run the AC outlets and appliances, etc... when boon docking using solar.

So, what will happen when I hook back into shore power? Can I run the shore power to my batteries and they will charge when plugged into shore? If this route, would that take place through what I'm hearing is called an "automatic transfer switch"? This would switch to charging my batteries from solar panels to being charged by the shore power when plugged in?

Long question short given that my interior lights are DC and my outlets AC what is the best way for me to make my system work so that I can just use my batteries when boon docking and still be able to run everything when plugged into shore power?

I know the knowledge is out there. Can't wait to see you everyone has to say!

-Lee & Molly
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Old 03-27-2016, 09:08 PM   #2
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South of the river , Minnesota
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Doing what you suggest is complicated and requires skill to set up.

In general, my strategy is to have very few things in the trailer that require 120v, and then I just don't use them when boondocking. The only exception is my wife's curling iron, and we have a small, portable inverter that we use specifically to run that. The laptop and phone chargers are all 12v.
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Old 03-27-2016, 09:22 PM   #3
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Naples, FL , Hood River, OR
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Quote:
Originally Posted by TwoAirHeads View Post
Hey there everyone. Long time follower first time poster. So long story short me and the girlfriend just got a '77 31' Sovereign with the rear bath. Currently interior is gutted and moving on to re-insulating and putting in solar.

Current state of electrical is that everything works fine. Owners manual describes the system as when running on batteries only the DC lights and DC (automobile cigarette lighter style) sockets work for appliances. The manual says that the AC sockets only work when hooked into shore power. There was a converter in the trailer and I guess this was simply to convert shore power to 12V DC to run the lights when plugged in.

Now here's the funny part. My knowledge on electrical systems is very crude. Now, the dilemma:

I want to install solar. But I'm trying to wrap my head around the switching between AC/DC for running lights, outlets, etc...

I understand that if I wire my new batteries into the system the existing 12V DC lights will operate just fine because that is what the 12V batteries will be putting out. Now, I'm also going to wire in an inverter to take that 12V DC power and be able to run the AC outlets and appliances, etc... when boon docking using solar.

So, what will happen when I hook back into shore power? Can I run the shore power to my batteries and they will charge when plugged into shore? If this route, would that take place through what I'm hearing is called an "automatic transfer switch"? This would switch to charging my batteries from solar panels to being charged by the shore power when plugged in?

Long question short given that my interior lights are DC and my outlets AC what is the best way for me to make my system work so that I can just use my batteries when boon docking and still be able to run everything when plugged into shore power?

I know the knowledge is out there. Can't wait to see you everyone has to say!

-Lee & Molly
Based on what you have written above…… a simple progression of power:

• Battery for 12VDC power
* solar charges the battery
* inverter/charger charges the battery on shore power

• Shore power present (power post or generator)
* inverter/charger charges the battery and 'passes thru' shore power to all
of your 'inverter' circuits (dependent on what inverter you choose)
* all other 120VAC outlets and appliances powered from 120VAC breaker box

• Boondocking
* battery powers all 12VDC loads
* inverter provides 120VAC FROM the battery for any 120VAC loads wired to
it

**NOTE**

The wiring of a full inverter/charger power system with solar requires a good working knowledge of both 120VAC and 12VDC systems and circuits.

****** If you are not intimately familiar with same, it is strongly advised to consult with a professional who does.

One mistake in your wiring will let out the 'magic smoke!', which is something that you never want to see……or worse!!!
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Old 03-27-2016, 09:24 PM   #4
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1992 29' Excella
2010 22' Interstate
Van By The River , Georgia
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What you want to accomplish is not uncommon. There are many threads related to this subject so do some searching. You may not find all the information in a single thread but you can combine the ideas found in several threads and figure out how to proceed.

There are a few people that participate on Air Forums that are well versed on the subjects of your project. Take a look at the related threads and you'll begin to see the names of Air Forums users who "know their stuff" and you can send them a private message to obtain more information.

On of the key items I think you've overlooked is an inverter. An inverter converts 12VDC to 120VAC. You can choose to operate one or two specific outlets via an inverter system or operate the entire AC system via the inverter.

Bear in mind that the size/rating of your battery bank is a key part of this situation. You'll need to take time to understand power consumption of various devices in your trailer to understand how much power you need. I've heard of some people that actually operate their air conditioner via their batteries! Most people simply operate one or more 120VAC outlets via an inverter so they can make coffee, operate the television or other small appliances.

Another key item is a switch that selects power from the shore connection or the battery system. I suppose this can be an automatic switch or a manual switch.

Lots for you to learn but it is quite possible.

on edit: the post just above mine (from lewster) is one of the users you should send a PM. lewster knows his stuff!
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Old 04-08-2016, 01:13 AM   #5
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Orlando , Florida
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Very helpful!
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