I would think you would be more interested in taking a generator with you on primative camps. If you reallyw ant to run 110v appliances.

A battery is great for lights, radio and other low consumption devices. But devices like Microwaves, coffee makers, hair dryers etc will suck the batteries down very fast through an invertor. In other words the Invertor will convert a battery power to AC that you can use to power your normal appliances, but you will need to recharge the batteries often..

Here is a website where you can read more about invertors and  DC Power

http://www.donrowe.com/inverters/inverter_faq.html

I seem to always be a little green with envy over my buddy who is outfitted with 4 golf cart batteries and solar panels.  His home made rig runs a marine refer his fan-tastic fan and his heater  along with all his 110v requirements with out a bump.  He seems to be well prepare for the apocalypse.

If I am correct most factory LQs have converters 110v to 12v. I do not have an inverter so we carry a generator.

However, I would love to install solar panels add an inverter in the line and go with out the generator.  I suspect their is some heavy costs involved in this.

Keep us posted on what you end up doing I am always interested in this topic.  As we are Brown enough with the Deisel and generator I would like to go more green in the next few seasons.

Depending on your generator, the four golf cart batteries can easily weigh two to four times its weight. You will be carrying this all the time, and paying for the additional fuel to do so. Your generator is paid for and in hand. Four batteries, a solar panel (s) a charging circuit and wiring installation, may be a cost you will be unable to recoup, over the operational expense of gas and oil for your generator.

The four batteries have a large storage capacity, putting out far more current, than anything but the largest solar panels are capable of maintaining. They are basically just trickle charging the batteries. Undoubtedly the batteries will provide a "greener" environment than an operating generator. However, what will be the cost to the environment, when the batteries and panels are manufactured for your installation? That left a "footprint" that is unrecoverable.

Comparing the costs of some fuel to some not so free sunlight, is a question only you can justify. You had to expend time, travel, materials and fuel, to earn the money you are willing to spend for these additional materials. That and everything you do has an environmental impact. How "green" you want to live, can only be answered by your individual knowledge and conscience.

Gard

Thanks for the insight G man.

Plus you forgot the main component.. 

I will never get that cost by the Bank!  (My wife)

Rose the actual wire itself can be the same.  A 110v circuit will use 12g or 14 gauage wiring. 

Since the plug in power will be the strongest current, by wiring for it you have use wiring that exceeds any 12volt needs.

Hi Rose66

When I 1st did my LQ I wired it for 110V (or in our case 220V) - I installed a large inverter and two deep cycle 120a/h abtteries. All my lights were 110v and my fridge is a small bar type unit. On our 1st trip the batteries were flat on the 1st day....the thing is that the inverter uses a lot of elec to run on its own....I also have a solar panel - but it is a waste of time....

What I have done now is replace all my lights for 12v units, and obviously changes the other end of the wiring to suite. Now I have a 220v outlet for the fridge and a micro wave etc. and the rest runs off 12v. I have a genny that I use during the day to keep the batteries full, and at night I turn over to the inverter to keep everything running.

So yes you can use the same wiring - just make sure you do all the connections properly. I would not have an outlet that you share between 110 and 12v - if you make a mistake you might fry something....

Painted Horse:  A little or incomplete knowledge can be dangerous.  The "plug in " power will be the strongest is true.  BUT power at 12 volts is a larger current than at 120 volts.  Look at the battery cable size in your car.  I believe you meant that the insulation wired for 120 volts is adequate for 12 volts.  The wire gauge should be sized for the maximum 12 volt current.

In your posting:  14g wiring is mentioned, it is rated for 20 amps (<3% drop within 40' circuit length).  A 120 volt appliance/s can safely draw 2400 watts.  A 12 volt appliance/s can only draw 240 watts before the wire is in danger of being overheated.

Never, ever, would I have a typical 120v outlet wired for both 12v and 120v.

Plug in a 12v appliance to the wrong side.....bang, zoom, smokin'

Rose, If you put 12v in your trailer it will be a completely different circuit than your 110v is, 110 outlets(duplexes) are just like the outlets in your walls at home, 12v outlets would be like a cigarette outlet in your car, 12v items cannot be run with the 110 outlets and vise-versa. You can power the 110 outlets with an inverter that produces 110v with 12 volt batteries, if you do this then the circuit would be a feed into the 110 side of the converter box.

The reason LQ's are built with 12v and 110v is because campers/RV's are designed to be self suffcient, i.e. you can go out in the middle of a field and have lighting, water(12v pump), hot water(LP), and heat(furnace that is LP and 12V). If you are doing your own LQ and you are never going to need to be self suffcient then 12v would be a waste of time.

If you are not familiar with electrical circuits ect. Please try to remember two very important facts, 1. You can't see electricity. and 2. It will kill you.

Rose, When Primitive you may want to get up in the middle of the night (Old people like me may get up twice).  The addition of a 12 volt circuit will allow you to have non generator and non 110v lighting.  12v circuits generally run all of your lights, water pumps, radios, hot water heater ignition and refer ignition.

You accomplish this with the addition of a converter not an inverter.  A converter serves as an inlet for your 110v line converting the 110 current to 12v current. Also allowing (if plugged into shore power (generator)) the use of all 110v items such as outlets and AC units. 

The oposite is the inverter which inverts 12v current to 110v current which makes a short run of a single battery which is measured in amp hours.

Take a look on the internet there are great articles about RV battery and ac power sources.  I found many very helpful.

Take a look at the converters on Progressive dynamics web site

http://www.progressivedyn.com/rv_products.html

There are also ac/dc distribution panels here to view.

Here is another web site that details use of 12v power

http://www.ccis.com/home/mnemeth/12volt/12volt.htm

Lots of the folks on this site have made their own LQs of few of my friends have also.  We once looked into the cost to send out a trailer and between shipping and installation we were well over 5k.  Not sure if it was a good or a bad deal but we ultimately ended up with a used factory installed LQ.

But no matter what you do be safe and have fun.  And keep doing what you are doing by asking questions.

Somebody probably will quote an actual electric code, but rule of thumb when wiring 120v circuits is:

14 gauge wire = 15 amp circuits

12 gauge wire = 20 amp circuits.

10 gauge wire = 30 amp circuits.

I would assume ( and I'm no expert here) The reason for such a big wire coming off your batteries is the amperage not the voltage. Same reason why an electric fence can run on such a fine strand of wire. It's high voltage but very little amperage.

Rose... Forgive my posting... I meant to show that wiring has several requirements...in a few words. 

A 14 gauge (or any gauge) wire can only conduct about one tenth the power at 12 volts versus 120 volts.  That limit is important when you wire for 12 volt battery powered devices. 

Painted Horse was incorrect to say that wiring for 120 volt will exceed any 12 volt wiring needs.   (in his defense, the subject can consume several weeks of class time to explore)

Agreed.  It just depends what you are wiring.  I would not use a 12gauge wire to wire a starter motor for an engine.

But for the conversation of wiring the lights in a LQ trailer it should be OK.

I did run some outside lighting on 14 gauge wire, and a person can tell due to the dimming when others lights are switched on.

Hosspuller is right about wire sizing....it's best to figure out how many watts the fixtures consume. Most 12v fixtures are rated in amps, so a person has to multiple amps x volts to = watts. As hosspuller stated, a 12gauge wire can safely carry 2400 watts, which equal 20 amps @ 120v. To get the same 2400 watts in a 12 volt system, the amperage would be 200 amps. That would require like 3/0 copper wire.

So when deciding to use 12gauge wire in a 12 volt application, you need to limit the wattage to 240 watts.

Most RV lighting uses a 1141 bulb, which consumes 18 watt. Some fixtures have 1 bulb, others have 2.

One 18 watt lamp, operating at 12 volts, requires 1.5 amps. So a 20amp 12v circuit could operate 13 1141 bulbs.

Other lights, like halogen loading lights, are in the order of 50 watts @ 12v.

That would be impractical and unnecessary. The largest awg wiring would be your battery cables sizing, which would be unmanageable when terminating inside the work boxes, or run throughout the chases of your trailer.

You can however, substitute a 12 awg wire for the 14 and 16 awg wiring. This is beneficial if you plan on adding additional lights, to an existing circuit at a later date. It's also better to have more capacity than not enough.

Manufacturers use the smallest wiring they can that meet codes, in an effort to save money. They are not concerned what happens to the product several years after the sale. If they save $40 on every trailer, the total over a year's time may be significant.

The only downside to the heavier wiring is an additional expense, and a little more difficulty with connections/terminations. It will simplify installation as everything is the same. However, if you have a known circuit with only a lighter load, many people would consider it wasteful using the heavier wiring.

It's your project and your money. As long as it's done safely, you can do it any way you want.

Gard

Once you understand what you can size a circuit, you really don't need the formula. Part of doing the job is doing it right. I can't imagine the work to go back through a finished LQ trailer and redo the wiring.

I'd be real hesitant to use anything heavier that 12 gauge wire. Most of the electrical boxes used in construction are darn shallow, 1 1/2" deep, barely able to fit the switch or outlet into. Smaller wire is easier to manage when making the connections.

I bit the bullet when wiring the 120v side of my system. I order 12/3 stranded boat cable...like Romex (Non-Metallic sheathed)...a black, a white and a green/ground. It was expensive, but very flexible.