Generator / Inverter / Batteries - RV-Dreams Community Forum

Paul and Jo · RV-Dreams Family Member

Generator / Inverter / Batteries

NorCal Dan · RV-Dreams Family Member

An inverter takes 12VDC from your batteries and turns it into 120VAC. A converter takes 120VAC and converts it to 12VDC to charge up your batteries. My inverter has a built-in charging circuit for the batteries. I don't know if all inverters do both jobs or not.

You will need a way to re-charge the batteries. One way is with a generator. Another is solar panels.

The number of batteries is a tough question, but in general more is better. I'm not qualified to answer the battery question so I will let some of our experts address the issue.

-- Edited by NorCal Dan on Thursday 5th of August 2010 09:27:33 AM

The Bear II · RV-Dreams Family Member

We have two sets of two batteries.

The first is the house battery set. This powers all of the 12v items in our 5th wheel (lights, water pump, heater, refrigerator) We use these batteries when we are boondocking and don't need 110V to power an appliance.

The other set is connected to an inverter/charger. We use these two batteries to power 110v items like the microwave, hairdryer, TV,DVD, laptop and satellite receiver when we can't use the generator due to campground restrictions (after 10PM, before 7AM).

The inverter/charger also charges both sets of batteries when the generator is running.

Originally, we had an Onan 5500 watt generator installed in our 5th wheel. When it died un expectedly on a trip we rushed out and purchased two Honda 2000i generators with a parallel kit that allows the two to be connected together to supply 4000 watts of power. We found this arrangement to be more flexible so we never replaced the Onan.

The generators are used during the day and into the night to power whatever we need. Sometimes we run them all day (when A/C is needed due to heat) and most of the time we run them for a few hours in the morning to charge the batteries back up and then in the evening to watch satellite TV or a DVD and recharge the laptop.

We are able to stay boondocked for weeks with this setup, as long as we have fuel for the generators. I have two 5 gallon fuel containers that I carry to get fuel at a nearby gas station.

Think of generators in terms of wattage vs. cost. The more watts you need, the more you'll pay for a generator. There are lots of RV'ers that get by with a 1000 watt generator. This sized generator will charge your batteries and power lights, a TV plus satellite receiver or laptop. It won't handle a microwave, hairdryer or A/C. These devices require lots of watts.

To power A/C you'll need 3000 watts at a minimum depending on the A/C unit. Most RV'ers wanting to power A/C will look for at least 4000 watts so you can run other stuff along with the A/C.

Another consideration is noise. A 4000 watt $300 generator will be very noisy compared to an $1800 4000 watt generator. You want to be able to sit outside the RV while the generator is running at full throttle. Plus you want it to be so quiet that your neighbors 20 feet away will barely hear it or not hear it at all. To get a quiet generator you need to pay extra.

The first generator I bought was a 6500 watt construction type generator. The kind you would see at a construction site to power the saws and compressors. When I started it up, I would see the other campers for several sites away head inside their RVs. It was very loud.

Hopefully this has given you the answers you need.

TXRVr · RV-Dreams Family Member

With respect to the generator, I would first suggest that you take stock of what equipment you want to run when boondocking. You can eliminate anything that is dual powered by propane: fridge, furnance, water heater, etc. If as you stated "propane is not available" then you forgot to fill tanks and that's another issue. smile Among those left would be the air conditioner which is a high current draw appliance and also the microwave depending on type. The slides would be another, but it would be short term. So logically, the cost of the generator would depend on the capability to run the ac. Anything else it is capable of doing at the same time is a bonus. I'm not a guru, but I doubt a $1K generator would do the job. You might want to consider one that runs quietly. There are back to nature boondockers who take a dim view of generator noise.

The inverter converts your 12V DC to 120 AC. The more costly of those are closer to pure sine wave output. You can do the research on sine wave. The length of the inverter output depends on input. The more batteries in your rig the longer the output without having to recharge them. One will absolutely not do the job effectively. I have six house batteries and can use everything except the ac for only 3-4 days without recharging.

You can get away with a modest inverter and generator if you don't mind power management. That's a comfort level issue for you.

Thanks, but I'll pass on the postcard. We lived in SC for six years. Got all the t-shirts. wink

-- Edited by TXRVr on Thursday 5th of August 2010 11:30:59 AM

Paul and Jo · RV-Dreams Family Member

TXRVr wrote:
With respect to the generator, I would first suggest that you take stock of what equipment you want to run when boondocking. You can eliminate anything that is dual powered by propane: fridge, furnance, water heater, etc. If as you stated "propane is not available" then you forgot to fill tanks and that's another issue. Among those left would be the air conditioner which is a high current draw appliance and also the microwave depending on type. The slides would be another, but it would be short term. So logically, the cost of the generator would depend on the capability to run the ac. Anything else it is capable of doing at the same time is a bonus. I'm not a guru, but I doubt a $1K generator would do the job. You might want to consider one that runs quietly. There are back to nature boondockers who take a dim view of generator noise.

The inverter converts your 12V DC to 120 AC. The more costly of those are closer to pure sine wave output. You can do the research on sine wave. The length of the inverter output depends on input. The more batteries in your rig the longer the output without having to recharge them. One will absolutely not do the job effectively. I have six house batteries and can use everything except the ac for only 3-4 days without recharging.

You can get away with a modest inverter and generator if you don't mind power management. That's a comfort level issue for you.

Since my new Montana 3455SA (not taken delivery yet) has both 12V and 120V outlets/systems and the specifications says it has an 80 amp Xantrex XADC converter, I assume that is what powers both outlets/systems when it's hooked up to an external electrical source. So, it's my understanding that when I do NOT have an external electrical source, I'm going to need batteries to power the 12V DC outlets/systems directly, an inverter to convert the 12V DC battery output to 120V AC to run the 120V AC outlets/systems, and a generator to charge the batteries and/or power the inverter and/or power the outlets/systems.

I really should get more information on the electrical system!

Can I get away with just battery/inverter combo, or do I need the battery/generator combo, or a battery/inverter/generator combo? I'm looking at a worse case scenario here where there is no external electrical source to recharge the batteries, not as a neccessity.

Paul

53 Merc · RV-Dreams Family Member

Paul, it all depends on your style of camping. An inverter is not really required, since it takes a really large set of batteries to supply meaningful 120 V power for any length of time.
The 80 amp converter, is the "battery charger" for your rig. If you are interested in running an AC while off grid, you will need a generator large enough to power that. Minimum of 3000 W. those get pretty spendy for occasional use. Lot of people have a built in Onan Genset that is seldom used (which leads to a whole 'nother set of problems).
If you intend to boondock once in a while, a couple of batteries are adequate for a couple of days.

Like others have said, you gotta decide what you will use, then equip for that. I betcha your DW will consider "roughing it" to be less than 50 amp campground power.

NorCal Dan · RV-Dreams Family Member

From the Xantrex website http://www.bestconverter.com/Xantrex-XADC-Converter-Charger_c_115.html:

The Xantrex XADC has been discontinued by Xantrex and no longer available. We have a few of the 30 amp distribution panels left but that is all, no more XADC converters. We will leave the data and manuals up for awhile for those needing tech information.
We recommend the Iota DLS series or Progressive Dynamics 9200 series as a replacement or alternative to the XADC.

I hope they are not talking about the unit in your new rig.

To shed more light on your questions...if you have a correctly sized generator then it will power your coach and everything in it. Assuming you don't want to run the generator 24/7...you will need batteries. All essential items in your rig, ie. refrigerator, furnace, water pump, hot water heater, lights, will run with just 12VDC as long as your batteries have enough juice (and a supply of propane).

If you want to run any of your A/C type items, ie. television, microwave, air conditioner, VCR/DVD, satellite receiver, then you will need to either run the generator, or, use an inverter to draw juice from the batteries to provide A/C power.

Batteries are important and you will need some way to recharge them. One option is to use your tow vehicle. Solar is another possible solution. And the generator.

Paul and Jo · RV-Dreams Family Member

What I am hearing is that I need batteries and a generator. There's no point in getting an inverter as long as I have a generator?

Correct?

So, why do people have inverters?

I've also heard of inverter generators. Are they different or just a fancier name for a generator?

Paul

Luvglass · RV-Dreams Family Member

Inverters are needed when you can't run your generator and want 110 volts. I don't think there's such a thing as inverter generator. A generator makes 110 volts and a inverter converts 12 volts to 110.

If you are planning on spending a lot of time off the grid and want to be able to enjoy 110 volt appliances, you need a bank of deep cycle 6 volt batteries, a generator, an inverter and a solar system.

There are any number of good descriptions of what is needed for off line living, and an internet search will provide them from more expert voices than you will find here I think.

Spend some time and find out how you'll be living before running out and buying stuff. We jumped and ordered a $5K generator for our rig, only to find out that we spend 95% of our time in campgrounds with electric service. I wish I would have waited.

Good luck,

Paul and Jo · RV-Dreams Family Member

Luvglass wrote:
I don't think there's such a thing as inverter generator.

http://www.apelectric.com/ProductDetails.asp?ProductCode=EF3000iSE&gdftrk=gdfV21065_a_7c276_a_7c712_a_7cEF3000iSE

Thanks for the information!

Racerguy · RV-Dreams Family Member

I have an 2800 Yamaha inverter style generator.They just produce a cleaner sine wave type electricity. I have owned it for two years now and have yet to need it due to the type of places we stay.That may change as we head toward Florida and will have to stay in some state parks. If I don't use it much the next six months I'll probably sell it and use the room for other stuff. Fred gave you good advise about learning how you will live before buying a lot.

Paul and Jo · RV-Dreams Family Member

Thanks Racerguy ...
I'll not get a generator until we're on the road but, knowing the type of people we are, we're not going to spending all our time at KOA and the like. We're probably going to be spending some time at State parks where there is no electricity ... hence my detailed questions about electrical availability. So far, I'm leaning toward an inverter type generator. Just makes sense to me.
Paul

Terry and Jo · RV-Dreams Family Member

Paul and Jo,

You may also want to look into a Pure Sine Wave inverter. Below is a link where it was explained by Howard and Bill Joyce as to why a pure sine wave was best. With their information, Jo and I made sure that our new fifth wheel had that instead of a modified sine wave inverter.

http://www.activeboard.com/forum.spark?aBID=91511&p=3&topicID=12771002

We would have liked to have had a Onan generator installed but with the weight consideration and the cost ($6000) we decided not to get it. One advantage of the Onan was that its carburator had a control where one could change the fuel mixture for the altitude that one is located. With our current Honda generator, after a few days we have to change the spark plug because the rich fuel at high altitude fouls the plug.

We previously had our Honda EU3000is generator and it is nice in that it had the "eco-friendly" feature that makes it quieter running. You can stand next to it and have a conversation without having to shout. With the generator, we can recharge the inverter batteries in our fiver.

Good luck with everything.

Terry

Paul and Jo · RV-Dreams Family Member

Terry and Jo wrote:
Paul and Jo,

You may also want to look into a Pure Sine Wave inverter.

Terry,
Do you have a link to such a beast? I'm worried about price. Would the 2800 Yamaha inverter style generator as described by Racerguy be the way to go?
Paul

Terry and Jo · RV-Dreams Family Member

Paul and Jo,

I saw your question on the forum while I was on break at work. Let me do some research this evening and I'll try to get you the information about the one we have.

As for the Yamaha that Racerguy refers to, I'd never heard of that one, so I don't know if it is a Pure Sine Wave or not.

Terry

TXRVr · RV-Dreams Family Member

Paul and Jo wrote:

So, it's my understanding that when I do NOT have an external electrical source, I'm going to need batteries to power the 12V DC outlets/systems directly, an inverter to convert the 12V DC battery output to 120V AC to run the 120V AC outlets/systems, and a generator to charge the batteries and/or power the inverter and/or power the outlets/systems.

That is correct. Typically, the only thing in an RV that is powered solely by 12 vdc is the water pump, fans, some inside lights, and all outside lights. The fridge may be dual 120vac/12vdc power. The inside lights, if fluorescent, are 120vac but that has been inverted from 12vdc to 120vac by their internal circuitry. If you have an external fridge/freezer it is usually dual power capable (120 or 12).

There is nothing in the product information that indicates that your model Xantrex will provide 120VAC to your rig.

Watts = Voltage x amps Air conditioning, the water heater, or a large microwave will draw about 13 amps each. Therefore, 120V x 13 amps = a 1560 watt generator. Run the micro and the ac at the same time and it’s then a 3120 watt generator. And so only as you turn on more equipment. There will be a placard inside a cabinet in your rig with the amps/wattage information. You can add it up and make an informed decision on the size of a generator.

Based on personal experience, I find the inverter a convenience item; so spend the money on a nice generator.

-- Edited by TXRVr on Monday 9th of August 2010 10:52:17 AM

Racerguy · RV-Dreams Family Member

Just a FYI from the Yamaha web site

Inverter System with Pulse Width Modulation - Industry-leading system that produces higher-quality and cleaner electricity. Results in pure sine wave as clean or cleaner than commercial power and can operate products with built in microcomputers.

NorCal Dan · RV-Dreams Family Member

I would agree with you about not needing an inverter if you plan on having shore power most of the time. The inverter is handy when you find yourself with no power and for whatever reason you can't run the generator. Some parks limit the hours you can run a generator, and sometimes you don't want to bother your neighbors with the noise and smell of a genny.

As I said earlier, all the on-board equipment I consider essential, will run on 12VDC and propane. So you need a good set of batteries to get through a cold night. You will want the furnace to run. And you will want the refrigerator to stay cold so your food doesn't spoil.

But at some point you will need some way to recharge the batteries.

Terry and Jo · RV-Dreams Family Member

Paul and Jo,

The inverter/charger installed in our Mobile Suites is the Xantrex SW3000. Below is a link to the company's website with the information. This is the first for us with this kind of equipment, so I can't answer any questions about it. Shoot, I'm still trying to learn all the stuff on our fifth wheel.

http://www.xantrex.com/web/id/303/p/1/pt/5/product.asp

Good luck with everything.

Terry

Luvglass · RV-Dreams Family Member

Paul,

I took a close look at the Yamaha mentioned and although it may be a great generator, it is not an inverter. An inverter has to be able to change 12 volts to 110 volts directly from the batteries.

It sounds like more of a marketing claim than anything.

Racerguy · RV-Dreams Family Member

I'm not an electrician but it seems to me 110 volts of pure sine wave electricity is 110 volts of pure sine wave electricity.It doesn't matter if it was inverted from 12 volts to 110 volts or created outright by the generator. All I'm saying is the generator is producing the same clean electricity as an invertor and a bank of batteries. Am I missing something here? confuse

Luvglass · RV-Dreams Family Member

I wasn't saying it wasn't good George, I was just pointing out it's not an inverter. An inverter is for when you need 110 and don't have a generator.

An inverter is to give you 110 volts when all you have is batteries. If you have a generator you don't really need an inverter.

The basic discussion has nothing to do with the quality of the output. Sine wave or modified sine wave will both work in most RV situations.

To really understand this subject, read Jack Mayers explanation at
http://www.jackdanmayer.com/rv_electrical_and_solar.htm#The%20Inverter/Charger

Racerguy · RV-Dreams Family Member

Sorry Fred, I misunderstood what you were saying ashamed

. I think the bottom line for the OP is you can have a invertor style generator and understand there will be times they won't be able to use it therefore won't have 110. Or you can have a true invertor and battery bank for 110 anytime but realize you will need a generator to charge those batteries when they run down.This electrical stuff gets real complicated and my eyes glaze over when some people get technical and don't explain things in laymen's terms.

Paul and Jo · RV-Dreams Family Member

Racerguy wrote:
This electrical stuff gets real complicated and my eyes glaze over when some people get technical and don't explain things in laymen's terms.

Hear, hear!

In fact, I'd much prefer a simple drawing of a typical setup. That would explaiin everything for me.

Paul

Terry and Jo · RV-Dreams Family Member

Paul and Jo wrote:

Hear, hear!

In fact, I'd much prefer a simple drawing of a typical setup. That would explaiin everything for me.

Paul

Paul,

If you go to Howard and Linda's home page and look for the tab for "Site Map" and click on that, you will see a whole list of topics that you may not know are available. In that area, Howard has put some good information on various aspects of RVing, including electrical and solar information.

Terry

bjoyce · RV-Dreams Family Member

Years ago, before my time, Escapees magazine ran a set of technical articles by Phred Tinseth called "Poop Sheets". They are on the internet http://www.phrannie.org/phredex.html. Read through the electrical sections.

Racerguy · RV-Dreams Family Member

Thanks Bill, Looks like good info for us technicaly challanged. The area Terry mentioned is good info also.

Howard · Host

I spent a lot of time putting together an electrical page that I hoped would get most people through. And it does include diagrams. smile

RV Electrical Systems

It starts off with the very basics and then gradually increases in techno-speak through batteries, inverters, and solar panels. Hopefully, it will be helpful to you if you go through it very slowly and then go to the links provided for more detailed information.

You can also go to Our Electrical/Solar System - A Phased-in Approach which gives a step-by-step account of why and how we phased in our electrical system upgrades.

You are on the right track, but remember you don't have to do it all at once. You can add components as you go as you determine how they fit your RV lifestyle. biggrin

Paul and Jo · RV-Dreams Family Member

Howard wrote:
I spent a lot of time putting together an electrical page that I hoped would get most people through. And it does include diagrams.

Howard,

I could HUG YOU TO DEATH but, that might be frowned upon in some circles.

The link and the information is just PERFECT! It's exactly what I, and others, need.
Not too much technospeak, actually has some drawings, no specifics on particular models or manufacturers ... but, that's not needed ... and has a lot of VERY useful information!

Where were you when I was searching for this info? LOL

Paul