Power questions

Lou, that didn't make sense to me either, which is why I asked him to clarify. I ended up thinking he probably had some small Group 24 batteries. Thanks for pointing that out.

Kev

Be careful of inverter definitions. There is square wave, modified sine wave, and true sine wave.

As for here at home I've got a 4kw Trace Inverter (Modified Sine Wave) powering the entire house without any issues. Modified sine wave is not all that bad depending on the quality of the modified sine wave. Most cheaper models tend to be more of a square wave output where what I'm using a multi-stepped output but not a true sine still. As for modified sine waves there is nothing wrong with them being I've got 4 computers and entire 2 story house power but a 4kw inverter that is a modified sine wave.

As for inverter size base that on th size of your battery bank Amp/hours. Like I stayed back to 1,200w on the RV because I've got just standard two 12V deep cycle batteries. 1,200w = 12 volts x 100 Amps. So it won't take long for the batteries to be wiped out even at 1,200w.

That's a much better waveform than I expected from a MSM inverter!  I've seen far worse coming out of a portable generator where the core has gone into saturation, and most portable generators run with their core saturated to save on weight and cost.

With 5 steps you'll have about 20% Total Harmonic Distortion in the waveform.  Commercial power specifies 5% or less THD to be considered "clean" power but I'd have no worries about using that power anywhere in my house.

The modified sine power to watch out for are the cheaper inverters that use only one step to approximate sine wave's peak voltage.  Not only do they have lots more THD but they vary the duty cycle of the pulse depending on the load and battery voltage.  Under worst cases (heavy load and low input voltage) their output approaches a square wave which is why microwave ovens don't produce as much power from them.

I would go with the 2000 watt inverter and the Honda 2000 for reliability.

That Trace (a product of Xantrex, not to be confused the TRC company brand) is a much better quality unit than the usual MSW.  There is no standard for what the term "modified sine" means, so anything from "square" to "multi-step" qualifies.  And square is the easiest and cheapest to design and build.

TRC also builds inverters, e.g. the SmartPhase products designed for solar systems. Different animal.

I agree with Gary, that that Trace Inverter is NOT typical of what you will find in the 1-3KW MSW Inverters readily available to the RVer.  I personally have never seen another that came close to producing that number of steps in it's waveform.

I know that this old house system isn't what you'd use in a RV. I just wanted to bring to light not all MSW inverter are bad. There is lots of photos on the Internet of what is called MSW and it nothing more that a square with a pause as it switches polarity. This I won't even consider a MSW it more a square wave. Yes. I've seen old square wave inverters too. 

I will admit the best solution is a true sine wave inverter but quality comes at a price as well. Being I'm also a boondocker and rarely need much for power being where I go there isn't any TV signal, barely any FM radio, absolutely no cell phone or WiFi I can get away with a simple Harbor Freight 1,200w Inverter and solar panel set. Works good for charging a laptop, cell phone, camera batteries, power a CFL Lamp or even my mini-vacuum cleaner. Might fire up a TV once in awhile to watch an old DVD movie but that's rare. No issues.

So my power needs are very low and used low budget inverter and solar but it covers what I'm looking for.

As for air conditioning, microwave, water heater (electric) you will need to consider either twin Honda (or similar) or some sort of large generator. I would not consider doing these devices on a inverter it will just drain the batteries fast. Being weight and storage is a factor I would look at the amount of amp/hours of batteries you got and consider your inverter size and loads against that number. I figured like in my system two 100 Amp/hour batteries (average size) which gives 200 amp hours. At 1,200w inverter will draw roughly 100 amp at full tilt. Giving a max run time of 2 hours tops (theory). But knowing my load requirements is barely 1-2 amps @ 120V at any one time is about 20 amp draw on the batteries that's at least 10 hours of run time (theory).

As for living on 30A @ 120VAC I've been doing it for over 15 years... Love It!  8)

Still seeing a lot of great information on here! Keep it coming!

Now im leaning towards the 2 Yamaha 2000 generators. Still considering a portable solar panel, but nobodys provided any insight on what wattage of panel i should be looking for to just charge and maintain my 6 volt batteries.

If i go with a 300 or 600 watt inverter for basically meeting my tv and dvd player needs, whats the best way to run it? Should i just run a short extension cord from under the bed storage to my tv or can i just plug in the shore power cord and get the inverter power through the outlets? If i went with the latter, is there a way to turn off the converter's battery charger?

Howdy,

If you are in the market for a new very quiet and cost effective small generator here is a new direct competitor to the Honda...

http://www.thefitrv.com/rv-tips/generac-iq-quietest-portablerv-generator-ever/

https://www.youtube.com/watch?t=3&v=hdUSO8kFKVQ

Generac iQ2000

http://www.amazon.com/Generac-6866-Inverter-Portable-Generator/dp/B0128KR4EE

vs.

http://www.amazon.com/Honda-Inverter-Generator-Portable-Powerful/dp/B005ND19AE

Cheap enough to have one around the house and for camping!

Happy Trails,

tom n tyler

I've run our TV/satellite off of a 150w inverter with a cord just to them as well as plugged the shore cord into the larger inverter to use all of the outlets. In my trailer the converter box has a breaker to shut off the converter.

When looking at solar, there are different ways of deciding how much to get. 1 watt per Ah of battery is one rule of thumb or you can figure out how much power you use and get enough solar to replace it daily. We scaled it up to the point that our solar acts like a small generator. The 750w easily runs a small air conditioner pulling 450w, a cook top pulling 470w and I am adding a Hot rod to the water heater that will pull just 450w and the batteries will stay in float.

In your case with two 6 volts, a 200 watt portable would match up well.

Solar charging: Everybody wants a simple answer, but there isn't one.  You need enough solar capacity to put back the battery amp-hours you use on a daily basis, but nobody wants to do the analysis and arithmetic to figure that out. Plus you need to consider the amount of sunlight available where you will camp. A 1000W solar panel still produces nothing if in the shade or on a rainy day.

A 100W panel produces about 6 amps, so if you have 6 hours of full sun on it you can charge about 36 amp-hours. Two 6v GC2 batteries have roughly 230 AH capacity, so you can replace about 15% of that in that time. On longer summer days you might get double that. On a rainy you get zero, so you need enough battery reserve to get through that time.

The 200W that Jim suggested is a decent way to start.

Lou Schneider said:

That's a much better waveform than I expected from a MSM inverter!  I've seen far worse coming out of a portable generator where the core has gone into saturation, and most portable generators run with their core saturated to save on weight and cost.

Click to expand...

Having looked at a whole bunch of scope traces and/or photograpnhs fo scope traces I will second Lou's comments.  Never seen one that good before.. I had to click on it and view full size to see that it was really MSW.. it's that good.

Thanks for all the great information everybody! I purchased a couple of Yamaha 2000s to get me started. Probably gonna get a 300 watt Go Power inverter before i leave on my adventure. Ill decide on solar panels once im out there on the road and figure out my needs.

300 watt good for TV's etc.  More watts lets you add Microwave, ELectric Razor (GFCI chain) and such.  I will always suggest TRUE SINE WAVE inverters mostly because they work with everything within their power rating.. I mean EVERYTHING.. MSW's not always no matter how good (And that one was very good).

I like the Yahama Generators  Noise: So close to Honda (1dB less) it's not worth mention.  Bearings: Superior.  All other specs. basically the same save COLOR.. Yellow is not as attractive to the 10 finger discount folks as RED is.

Carterc1978 said:

Im trying to figure out an inverter set up that I already touched on on another post for running a tv and dvd.  I was planning on a portable solar panel to maintain my 2 6volt batteries. But what are your thoughts? If I am already planning on a generator (that could obviously be used for battery charging),  is there really a reason to spend the extra money on solar?

Click to expand...

I LOVE my solar. I especially love NOT running my generator.  Everyone is different but, for me, the cost of solar (relatively low - DIY system) was more than worth it to me.

What type of TV do you have?  The newer LED TV's use very little power.  I'm not sure about DVD players.  In any case, I agree with the others, a small-ish (100-150 watt) inverter will suffice for this purpose.

I too am in the west and generally avoid the heat by going up in altitude. Obviously, that doesn't always work nor is it for everyone but maybe a hint that you will find helpful.