Help need choosing an Inverter

We are thinking of adding an inverter.  I want a pure sine wave due to laptop.  Need help deciding if I want a inverter only or a inverter/charger.

One shop recommended an Go Power GP-SW3000 Pure Sine Wave Inverter ( http://www.gpelectric.com/content/products/ViewProduct/?i=GP-SW3000 ).  I appears to be an inverter and not the inverter/charger the tech. said it was.  I know nothing about this company or how there inverter line rates?  Any insight?

Zantrex ( http://www.xantrex.com/ ) has all lots of inverter & inverter chargers but the one considering Freedom SW3000 inverter/charger seems to have fire issues. 

Other brands?

I am not sure of the function of the charger function of inverter.  I think it allows equalization of batteries and helps control the charging of the batteries???  How does just an inverter function vs inverter/charger?

From above rambling you can tell that I am confused and not even sure how to ask for the information.  Please start on the dummy level and take me to understanding.

Jennifer

Don't get a pure sine wave inverter just for a computer, they run just fine on modified sine waves.  If you have other electronics that work better on PSW then by all means get one, but if not, save the extra money.  The Xantrex inverter/chargers are excellent and are original equipment on many RVs.  The charger will be a 3 stage model and do a much better job of charging your batteries than most converter/chargers which it will replace.  Size the inverter to the size of your battery bank.  I you have the typical 4 golf cart 6V batteries, then a 2000W unit will be the correct size and will have a 100A charger.  For 6 batteries, a 2500 or 3000W model is better suited.

The function of the inverter is to make 120VAC from the 12VDC batteries.  The charger will have an equalization function if it's needed.

All in one inverters/chargers are convenient, but they're also expensive.  Their advantage is they're plug and play.  When you're connected to AC power, the built in transfer switch sends the AC to your circuits and the charger charges your batteries.  When you disconnect from AC, the inverter is automatically connected to your circuits and all you have to do is turn on the inverter to get power.

If you already have a good multi-stage converter like the Progressive Dynamics you won't gain much by disconnecting it and going with the multi-stage charger in an all in one inverter/charger.  If you have a single stage charger that doesn't charge your batteries well then the multi-stage charger in the alll in one will be an improvement.

Stand-alone inverters are less expensive (often a lot less expensive) but require some manual switching.  You never want to feed AC shorepower into the inverter, so you'll have to arrange a way to switch between shore power and the inverter.  I have a stand-alone inverter so I just put a 30 amp outlet in the compartment where I store the shore power cord.  The outlet is connected to the inverter.  When I disconnect from shore power I plug the end of the shore power cord in the inverter outlet and it sends power to everything in the rig. 

If you're feeding the whole rig with an inverter, either an all in one or a standalone, you'll have to make sure your power hogging appliances stay off when they see the electricity.  Switch your refrigerator to gas only mode, make sure your the water heater's electric element is turned off, etc.

If you're doing this with a standalone inverter, you'll also have to turn off the converter.  Otherwise you'll set up a loop consisting of drawing 12 volt power out of the batteries, going through the inverter to get 120 volts, passing through the converter to get 12 volts and sending that power back into the batteries.  Since each stage is less than 100% efficient this wastes a lot of battery power.

Or just run the output of the inverter directly to the appliances you want to run from it, independently of the rest of the rig's electrical system.  Put an outlet next to your laptop, etc. and turn on the inverter when you want to use them.  If you're plugged into electricity the power will come from the converter, so you won't be pulling power from the batteries.

The size of the inverter depends on what you want to run from it.  If you want to run your laptop, the TV, DVD player and satellite dish, for example, you can get by comfortably with a 600 - 1000 watt inverter and your existing batteries.  If you want to run the microwave, the coffeemaker, a hairdryer, etc. you'll have to step up to a 1500 or 2000 watt inverter and at least 4 batteries. 

I know this is a lot of information, so I'll stop now (finally!) 

Ned, we are going with 4 Trojan T105 which I think is 450Ah.  If I go with modified sine wave what do you think about the Xantrex RV Series GS:  http://www.xantrex.com/power-products/inverter-chargers/rv-series-gs.aspx

Is this what I should be looking at or another model.  I did not see and modified sine wave inverter that was a charger also but maybe I did not look hard enough.

I am not sure what will not work with modified sine wave but I had heard some laptops did not play well.  Is there a list?

Oh Ned, totally off topic, but I just got notice that the Kindle 3 has just shipped.  Hope to have it in 3 to 5 days.  Let you know more when I know.

Thx,  Jennifer

The 4 T105 batteries are rated at 440AH so you want a 2000W inverter.  Whether you need an inverter/charger depends on what you have now for a converter/charger, as Lou describes.

I don't know of any computers that don't work well on MSW and we've had a lot of different ones in the past 13 years, all run on our Heart 20D MSW inverter.

I would be interested in your report on the Kindle 3.

Oh Lou, please do not stop  ;D  Yep, lots of info. and I need to read it again and then have Dan read it too.

I do not know what converter we have but think not a good multi-stage converter.  I think it is a single stage.  I know it is flat looking so about 2x4x8+ and located in storage compartment  .  Helpful ain't I?  :

We are thinking inverter to power the computer(s), TVs (2), DVD, TV satellite dish, electric sockets in kitchen and dinning area, coffee pot, perhaps adding a reading light and maybe the electric socket in the bedroom.  Thinking of using generator for microwave and few times hair dryer used (my hair short-can brush & go).  We will need to recharge various devices (computers. cell phones etc.).

Given the above, how long could a 2000 watt inverter provide power before recharging batteries?

Later on the rest after Dan has read it too,

Jennifer

Really stupid questions:

So if I increase the battery Ah then do I need to increase the inverter watts required or does that just allow the inverter to provide power longer? 

Does the inverter watts rating relate to running all the devices connected at the same time?

Jennifer (DH knows this)

You can use any size inverter with any size battery bank but it works best if they are matched.  You could add 2 more 6V batteries, for a total of 660AH, and still use a 2000W inverter.  You will be able to run on the inverter for a longer time and the charger, if you have an inverter/charger, will take a bit longer to charge the batteries.  Choose your inverter size based on your power requirements.  For your needs, as you described, a 2000W inverter should be adequate.  If you need an inverter/charger, the Xantrex Freedom series is a good choice and very common in RVs.

Yes, the inverter watts are the maximum load you can place on it at one time.  Keep in mind that a 2000W load on the inverter will result in about an 160A draw on the batteries.  At that rate, they will last for less than 2 hours before needing recharging.

I was not thinking of adding more batteries but increasing the Ah by going to the four Trojan T125 or T145.  That gain in Ah would be nice but I am guessing not enough to worry about in the real world.  I do have the height room for the L16 batteries if that would be adviseable in the future. 

Dan is putting together a chart of each device power requirements -- and yes there will be errors.  We do not plan on using everything at once so hope never to get near that 2000W load.  Thinking 4 to 6+ hrs. TV, 2 hrs. coffee pot on, and lots on computer in future when I can connect online.  I do not have a cell phone yet so no air card nor any other method if no wifi available.  Lots of Kindle reading  :-*

Given our current converter I am leaning toward the inverter/charger.  (unknown if our converter helped kill the 2 12 V batteries the T105 replacing)  I still do not understand the difference between the Xantrex Freedom series and the Xantrex RV Series GS.  Need to do more study.

Thanks once again for all you help, invaluable!
Jennifer

I did not see and modified sine wave inverter that was a charger also but maybe I did not look hard enough.

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??? The Xantrex GS inverter you linked to is a modified sine inverter with charging function.

And all the Freedom 458, HF and HW series are modified sine wave inverters with charger.

The amp hour difference in the batteries you cited is not that great. 
T-10-5 is what 220 amp hour.. T-145 is 260

That's 40 amp hours difference, less than 20 percent

Not really that great.. However if the existing batteries are in need of replacement....

GO FOR IT

Mangum Energy and Outback are two high end manufacturers, made in the US.

Since we have only two 12 batteries I went with the MMS series by Magnum-

Talk some with Dan and he still wants the pure sine wave even if it cost more.  This weekend he hopes to complete the power requirements chart. 

John, we just replaced the 2 dead 12V with 2 Trojan T105.  Need some tray modification for the next two.  Time crunch delayed that.

BB, thanks for the other inverter brands.  Checked out the Magnum site and it lead me to 2 local companies which may be able to provide info. and perhaps install.  The OutBack webpage gave me a virus warning so did not go there. 

RV Roamer, once you said it I knew the Xentrex GS was modified  Duh 

Hope to have more info. soon... and likely questions. 

Thanks again for your help.  I sure do need it.

Jennifer

Magnum makes some popular inverters also, so it's a good alternative to the Xantrex models.  As long as the price doesn't affect you, get a PSW inverter, you may need it for something later anyway.  Do get a optional remote control panel for whatever inverter/charger you buy.  The standard panels are almost useless.

The Xantrex Prosine is pure sine wave inverter/charger. Comes in 2kw and 3 kw models. Magnum has good ones too.

You still need to address whether you want to keep your existing converter charger and add an inverter, or replace the converter/charger with an inverter/charger combo.

In any case, the major chore is figuring out what circuits in the house should be powered by the inverter and somehow managing to wire them to it.  Moving circuits from the existing load center to the inverter can be fairly simple or a nightmare, depending on how the coach is physically layed out.

Another choice is to simply plug the whole coach into the inverter outlet(s), but that means you have to do some manual shutdowns of the existing converter charger first and you would also need to manually shut off major power appliances, since you don't have enough power for everything.

The charging rate could be a factor in buying also;  we got Powertech AGM batteries, by Deka, US made in PA I believe and I was told that a 50/75A charge rate was best, some of the inverters throw an awful lot of amps into the batteries when charging.

Also, I was told that Xantrex has gone Chinese-can anyone confirm this?

Has anyone looked at where all the toothpicks are from lately?????

Forgot all about this site, some good info

http://solatrontechnologies.com/

After the glitzy intro you can scroll down a bit and see a menu box , check out the inverter section.

A good quality charger won't ever overcharge a battery, no matter how large its peak rate may be, nor how few/small batteries you may have. The rate is adjusted to what the battery can handle effectively. Most inverter/chargers have a good three stage charging algorithm.

Does voltage or current vary.

BB said:

Does voltage or current vary.

Click to expand...

Yes.  In bulk mode, the current is held constant as the voltage rises.  When it reaches a predetermined value, say 14.4V, then the charger goes into acceptance mode, holding a constant voltage, say 14.4V as the current drops.  When the current drops to a predetermined value, say 2% of the battery capacity in AH, the charger enters float mode, holding a constant voltage, typically about 13.5V for flooded cell batteries.

The values I used above are the defaults for my Heart 20D inverter/charger.  Most of them can be changed using the Link control panel.  I would expect other 3 stage chargers to work in a similar fashion.