# Good Inverter



## Big Dreamer (Aug 6, 2010)

Okay now for a question about inverters. I am looking for a minimum of 600 watts to maybe 3000 watts in a pure sine wave inverter. Where is a good place to purchase and or suggestions on what type would be a good one to look at. I need at least 300 watts to run my stove in case the power goes out and I would like to be able to connect a light to it as well so that is where I came up with the 600 min. Price is an issue so I would like to keep it as low as possible but understand you get what you pay for. I currently have a 80 watts solar panel and a 228ah battery. The plan is after the inverter to add another panel or two. I just need this right now for a backup system. I seem to get more good educated ideas from this forum than most. Thanks in advance


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## Valleyguy (Jan 5, 2011)

Sounds like your DC system voltage is 12 volts, most likely?? And I am also guessing the stove is a gas (either NG or propane) with an glow bar, that is where the 300 watt load is coming from? 

It would be a lot of $$$ to buy something like an Outback inverter/charger if this is a very low usage, backup system. You are starting ~$1870 just for an FX/VFX sine wave inverter alone. 

A cheaper sine wave inverter with a battery charger is the Magnum MMS series. They are for mobile applications but for around $1100 you get a good waveform and a charger. The MMS is only for 12 volt apps. 

If you don't care about an integrated inverter/charger there are a few stand alone inverters. Samlex is at the lower end and Exeltech is at the upper end for home use. Neither of these unit are good with heavy startup loads like a fridge or motor with a high initial surge. They would be fine with a resistive load like an oven glow bar. These are going to be the cheapest route to go, by far. Of course you will probably need a battery charger to use in conjunction with a gas/diesel generator for those times when the sun isn't shining, adding additional cost to one of these units.

Xantrex has sine wave units if you want to sift through their products. 

It's a simple question you ask but the answer really lays in what you ultimately want the system to do.

Rick
*Homepage*: www.power-talk.net
*Forum*: forum.power-talk.net/


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## Big Dreamer (Aug 6, 2010)

Yes the system is a 12 volt and I am using a Corn / Pellet Multi-fuel stove for heat. The 300 watts is on the high side but it does have 4 motors in it 2 blowers and 2 augers. If they all are running at the same time which would be less than 10 seconds you still donât hit 300 watts. 

The power might go out here maybe once or twice a year and the last couple of years it has went out in the winter so I would like to have heat. My home is all electric and I just want to run the stove and a lamp if needed but hopefully it is not needed. It is for a back up system only.

I am looking to try and stay under the $500.00 mark if possible on the inverter. 

I am looking at something like this http://epweb.angelfire.com/solar-pv-system.html which is a link I found on Built it solar. It does not say what type of inverter he is using other than it is 1200 watts but I guess I could email him and ask. 

If I am putting money in I guess I would like to spend it now and get a good quality unit instead of buying a cheap unit and having it not work when needed. So I guess in general a low budget and good quality is what I am after so that does narrow the field a good bit. 

I will check your website out a little more when I have more time. It looks interesting!
Thanks


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## mightybooboo (Feb 10, 2004)

http://www.hodgesmarine.com/Xantrex-Prowatt-Sw2000-2000w-True-Sinewave-Inverte-p/xan806-1220.htm

2000 watt sine wave by Xantrex.Ive always had good luck with their products.Bought this but havent hooked it up yet. 2000 watts sine wave for 334.00 dollars,thats mighty hard to beat!

youtube
[ame]http://www.youtube.com/watch?v=xgkY0mL2EMQ&feature=player_embedded[/ame]


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## Jim-mi (May 15, 2002)

Regardless of the inverter you get, the electrical requirements for that "heater/stove" are going to eat up that small battery in a big hurry.............
Glow bars stay 'on' for many minutes.
Blowers suck plenty of juice.... 

You need far more charging capability before this thing will work.


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## wy_white_wolf (Oct 14, 2004)

Exeltech seems to be a fair small/mid range inverter

http://www.solar-electric.com/exsiwain.html

I agree with Jim. Your going to need a more charging capacity/storage to do this.


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## roachhill (Jul 8, 2009)

Why would a stove or light require a pure sine wave anyway. Wouldn't modified wave do just as well in this application? It would get the price down to less then $100 and you'd never know the difference for those uses.


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## mightybooboo (Feb 10, 2004)

Maybe not more charging if rarely used,but also agree,more batteries are called for.A genny would be a very nice addition to your dream

Ive read of guys with hunting cabins,a couple panels,lots of electric storage does them well on a couple times a year visit


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## mightybooboo (Feb 10, 2004)

roachhill said:


> Why would a stove or light require a pure sine wave anyway. Wouldn't modified wave do just as well in this application? It would get the price down to less then $100 and you'd never know the difference for those uses.


Because he wants to be able to use it for other applications in the future? That was what i read into it


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## wy_white_wolf (Oct 14, 2004)

roachhill said:


> Why would a stove or light require a pure sine wave anyway. Wouldn't modified wave do just as well in this application? It would get the price down to less then $100 and you'd never know the difference for those uses.


Blower/auger motor. Wouldn't want a back system to burn them out and lose all heat. I'm sure a mod- or square-wave sine inverter would void any warrantee on them.

This is one place it would be better to be safe than sorry.

WWW


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## Big Dreamer (Aug 6, 2010)

Well lets start with the Modified and pure sine wave. From what I have read you would need this for electronic devices with processors and this stove does have that with a digital readout and controls. I have also read that motors do run well with the modified sine wave but better and more efficient with the true or pure sine wave. Not sure how true that is but that is what I have been reading and I would like to use it for other things in the future.

What current would it take for an inverter to make 1 amp of AC power. I am assuming since they are not real efficient that it is not 1 amp in get 1 amp out but would it be 3 to 1, or 5 to 1? If I could find this out I could calculate how long the battery would last. I am looking for maybe an hour or two maybe 3 at the most.


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## TnAndy (Sep 15, 2005)

Good inverters are in the 90+% range of conversion from DC to AC....I'm thinking my Outback is rated 92 or 94% efficient.


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## Jim-mi (May 15, 2002)

All motors run very warm to hot on mod/sine....
It would be a crap shoot as to how the electronic control board in that stove would like/dislike mod/sine.

you need more storage . . . .period.
bottom line; go sinewave.


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## Big Dreamer (Aug 6, 2010)

Sinewave it is storage how much? At 300.00 per battery I need an exact number you are talking about or away to calculate the requirements.


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## mightybooboo (Feb 10, 2004)

My goodness,300 a battery????

I will let the battery experts answer your question,but I think you can do better.I have a friend with 8 t-105 in a 25 foot motorhome and he hasnt blown himself up with hydrogen fumes yet,YMMV but I doubt by much.

Good choice going sinewave IMO,FWIW,I like good stuff too if I can afford it.My modified Heart Freedom 458 couldnt run my micro with digital controls,and it is a darn good mod sine inverter,ran TV and sat and CFL bulbs,refer and freezer great though,couldnt run the Sony Stereo with digital either.Desktop comp ran fine,their power is so dirty they cant tell the difference,my Samsung screen had a slight buzz from speaker but the LCD pic was fine.Wireless modem fine too.


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## idahodave (Jan 20, 2005)

1 amp at 120 volts is 120 watts.....120 watts at 12 volts is 10 amps.

So with an inverter that's 90% efficient 1 amp out at 120 vac would take about 11 amps at 12vdc


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## Big Dreamer (Aug 6, 2010)

Lets just say it is 12 amp and if the stove pulls 2 amps that would make the load on the battery around 24 amps so now correct me on this but 228AH / 24amps = 9.5 hours is that correct?:stars:


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## Jim-mi (May 15, 2002)

Your idea of using from a battery is flawed. 
Like using all ten gallons from a ten gallon fuel tank.
You DO NOT do that with a battery.
If you do that, that bat is VERY soon scrap. 
It is best not to use any more that 50% of a bats capacity . . before recharge.
Even better to use only 20 to 30% off the top of a well charged bat.


Yes booboo that Heart 458 is a good mod/sine inverter . . . .but ya just never know what *electronics* unit will NOT run from it.


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## Valleyguy (Jan 5, 2011)

Lot of really good comments from real people that actually use inverters. Big Dreamer, you are certainly not getting a sales pitch which is what the alternative energy store will guys will do. 

I think I see where you are coming from. The stove, I mistook for a "stove" you cook on but the pellet stove you are talking about is definitely worth the price for a sine wave, you already know that. I would say the digital control timing would be really messed with a low cost modified sine wave inverter. You will have to decide what your budget will buy in this case. I will let that one rest for now.

The battery. The 228 AH rating is for the DC draw and only a part of it is usable. Use 50% as a rule of thumb for a deep cycle battery. Right there you have essentially only have 114 ah's to use. Problems arise however. 

First, that 228 AH rating is for a draw over 20 hours typically, but not always so watch that little detail. In theory you could pull ~11.4 amps for 10 hours to get to a 50% Depth of Discharge. If you put a load on it that exceeds the 11.4 amps then the Peukert effect kicks in and you don't have your 114 amps anymore. 

Second, the 228 AH rating is for a brand new battery and a best case scenario. Us in the real world probably never see that type of capacity, it may only exist in the lab. 

I think the last questions you asked, stove is pulling 2 amps, that is 2 amps at 120 volts. Your 12 volt battery would have 20 amps DC being pulled out. You have the Peukert effect in play along with the inverter efficiency plus wiring loss, however large or small it may be. And are your batteries at 77Â° F which is most likely where they are rated because colder means reduced capacity.... Sounds simple and it is but there are a lot of factors in play here. You are on the right track here, getting a little education.

Rick
*Homepage*: www.power-talk.net
*Forum*: forum.power-talk.net/


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## Big Dreamer (Aug 6, 2010)

> Your idea of using from a battery is flawed.


Let me see if I understand now. You have a solar panel and a battery that makes and stores electricity and you add an inverter to make AC from DC but you canât use that electricity that is stored. 

That seems to contradict everything I have read in the last 30 to 40 years. You keep telling me it will not work and I need more capacity but you have not given me an answer to the question how much. I understand you do not drain a battery I understand that is a bad thing and I agree completely. I have said that I was looking at anywhere from 1 â 3 hours of use. 20 to 30% of the battery capacity would be 1.9 to 2.8 hours of use. Letâs say I get one of the inverters mentioned above how many batteries are you telling me I need to get to do what I want? 2 maybe 10 I am not trying to be argumentative truly looking for an answer so I can plan to get a correct and working system that can be modified and expanded in the future. I need to start somewhere and there is no way that I could have a Larry Hagman type setup ever. So I have 1 solar panel 1 battery and looking to get 1 inverter with intentions of adding more solar panels and batteries in the future. So how many 228AH batteries would it take to draw 2 amps of AC current for 1 â 3 hours?

Please donât take anything I have said to be done in a mean manner that is not my intention I am just looking for some answers.


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## Big Dreamer (Aug 6, 2010)

Good answer Rick that makes since. 
Thanks
Gerald


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## trkarl (Dec 15, 2009)

Big Dreamer said:


> So how many 228AH batteries would it take to draw 2 amps of AC current for 1 â 3 hours?
> 
> Please donât take anything I have said to be done in a mean manner that is not my intention I am just looking for some answers.


2 amps 120v ac = about 24 amps 12v dc
So for 3 hrs run time you will need about 75 amp/hrs total.

The 228Ah rating is most likely the 20hr rate which is about an 11 amp load.

Your load is about the 10hr rate so the capacity will be less than 228AH for one 12v string.

Look at this chart and compare the capacity rate of this battery compared to the discharge rate. 
http://surrette.com/pdf/S-460.pdf?p...d65c08&phpMyAdmin=3jSJ-jdC5E7b53DHgV8TGvpSCF6

This has to do with peukert's law.
http://www.bdbatteries.com/peukert.php

If these are 6v batteries then you will need 4 wired in series / parallel for 456 amp/hrs capacity at the 20hr rate.

This way a load for 3 hrs at 24 amps will draw down less than 20% depth of discharge which is where you want to be.


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## Jim-mi (May 15, 2002)

As I sit here and type this the outside temp is a big +5 above zero in my area of northern Mich.
With out my heat (propane) I would be in deep doodoo.
I would never design a system for a customer that would 'barely get by' (your 3 hour power outage)
Thats why I'm having a hard time thinking 'small' 

Should a major storm knock the grid down . . .Who knows how long before it is back up. . . .A major transformer?? that has to be trucked in from who knows where.........
I would rather think for a 3 day outage...........

Another thing; as you use up the battery the voltage goes down so any decent inverter is going shut down way before you have used that>228<

A good first step would be to get a "Kill-A-Watt" gizmo and record what that 'stove' really uses.

With that data it would be far easier to design a three hour-or-a three day system........................


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## trkarl (Dec 15, 2009)

Jim-mi said:


> As I sit here and type this the outside temp is a big +5 above zero in my area of northern Mich.
> With out my heat (propane) I would be in deep doodoo.
> I would never design a system for a customer that would 'barely get by' (your 3 hour power outage)
> Thats why I'm having a hard time thinking 'small'
> ...


Agree 100%.
Also the temp at +5 above zero would have a serious effect on the battery capacity if they got real cold.
The only reason I gave the figures I did was the scenario presented was the 3 hr power outage with maximum draw of 2 amps ac.

Definitely need to do some "real world" data recording but at least that was a start.


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## TnAndy (Sep 15, 2005)

Big Dreamer said:


> Let me see if I understand now. You have a solar panel and a battery that makes and stores electricity and you add an inverter to make AC from DC but you canât use that electricity that is stored.


Really ? Who said THAT anywhere in this thread, or even in this forum ?







Big Dreamer said:


> That seems to contradict everything I have read in the last 30 to 40 years. You keep telling me it will not work and I need more capacity but you have not given me an answer to the question how much.


Well, go BACK and read thru this thread.

Your original post was asking about what inverter to buy in the "600 to 3000w" range ( which is quite a spread ), and somewhere down thru the thread you got off inverters and switched to battery capacity. 

So if you don't like the answers you're getting, PERHAPS it's because of the way you're asking the questions, and supplying the information.


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## Big Dreamer (Aug 6, 2010)

Wow 
It seems that my questions have been taken all wrong and I will apologize for that. My intent was not to argue rather to get information about inverters that some of you have used and tested. I did answer the question ask the best I could and added what information I thought would be needed to get the information on the inverter. Again not meaning to be argumenitiave at any point. I do appreciate all the information and have learned a great deal.

Thanks


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## idahodave (Jan 20, 2005)

I'm guessing your battery is a group 8D, used in big trucks, buses or tractors. If it's not that big, the 228 amp-hr rating is in question.

The battery (if in new condition) would run your stove for a couple of hours....it might even make the 3 hours once or twice before it's damaged.

Samlex makes sine wave inverters (never used one) that include chargers and transfer switches, you might look at the S-1012A.


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## Big Dreamer (Aug 6, 2010)

The battery I have is a Deka 9C12 made for floor scrubber/sweepers. That was what they recommended for what I am intending to do. I need to read up on the inverter charger sounds like they would be a good alternative. Thanks


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## mightybooboo (Feb 10, 2004)

Jim-mi said:


> Yes booboo that Heart 458 is a good mod/sine inverter . . . .but ya just never know what *electronics* unit will NOT run from it.


Absolutely,anything with a digital readout was non function for sure,actually did surprise me though how much it did run well actually.But certainly had limitations for sure!

Cant wait to try my SW2000 Xantrex pure sine,that should really be nice.


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## mightybooboo (Feb 10, 2004)

idahodave said:


> Samlex makes sine wave inverters (never used one) that include chargers and transfer switches, you might look at the S-1012A.


*Do NOT get a Samlex*,one of the Ladies here went thru three of em in a matter of months,it was HORRIBLE!

Be patient Dreamer,you questions are very reasonable and the folks here will get you figured out with various options on the battery question.

I really think 4 of the 6 volt trojan t-105 would be a nice backup or 2 of the L-16 size and I would throw in a Cheap crappy generator from Costco( they DO work,just arent that durable) for when you exceed the batts limits,then you run genny and recharge batts and run other stuff at same time,like the freezer or washer or whatever needs a good load.

As for cold,they make a very good point.Someone here has his backup batteries indoors by the wood heater (not too close LOL) and thats working for him.Just put them in something plastic like an open tub or better yet the plastic battery holders fro Cheapo Auto Parts (whatever it is your neck of the woods) and good to go.

NOW.....when you decide on the battery(s) you want(after you pick an inverter), the wiring pro's will tell you the PROPER sized cables,very important.Im not that big on wire size numbers I have to look up every single time,in my case I went WAAAAAY overboard on size so with upgrades Im well covered.The pro's here can really set you straight on those.

So we need to know your choices on.....

1-inverter
2-battery choice-He has a DEKA 9C12 12 volt 220 Ah battery (maybe add another of your super fine Deka's for 440 ah,200 ah usable)
3-wire sizes
4-backup genny if it floats your boat.My backup is a Honda EU2000 watt,does all I need,not great,but with plugging in this,than that,Im covered.I went with it for quiet and portability.


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## roachhill (Jul 8, 2009)

If you really want to be able to design and expand a system including all this math I would read The Solar Electric Home. It's a really good book and one of the few that explains all the math neccesary to determine, usage, capacity, efficeincy even wire sizing. Incidentally I'm familiar with the problems associated with modified wave inverters but I've been using them for years without any problems. Even gone so far as to run my desktop computer in my semi for a year off a modified wave with no ill effects. Guess I'm just lucky I suppose.


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## PD-Riverman (May 24, 2007)

Why don't you do this. Decide on a inverter, buy it, hook it up to your battery/solar set-up. Plug your heater into it and give it a test run-------See how long it will run it with one battery, if you need it to run twice as long------add another battery------if you need it to run 6 times as long----yea add 5 more batteries. Now with alot of batteries you will need more than the 80 watt panel to full charge them, so you will need MORE solar Panels or a good on-grid battery charger that will keep them charged until power goes out.


I feel without you putting a watt meter on your heater/stove and get some exact readings, all this figuring how many batteries you need will just be a Guess. Even with some watt readings/usage batteries can be different even though they are the same make. To me a Test Run will Answer Most All Your Questions! Good Luck!!





Big Dreamer said:


> Wow
> It seems that my questions have been taken all wrong and I will apologize for that. My intent was not to argue rather to get information about inverters that some of you have used and tested. I did answer the question ask the best I could and added what information I thought would be needed to get the information on the inverter. Again not meaning to be argumenitiave at any point. I do appreciate all the information and have learned a great deal.
> 
> Thanks


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## mightybooboo (Feb 10, 2004)

The 2 posts above,really good ideas.Especially the hook an inverter to what you have and see what it really uses and upgrade from there.

Also 2 dollar a watt panels are here now,and craigslist panel prices still dropping,I see a lot at 1.50/watt,couple weeks ago saw 2 for 1 dollar a watt.They are used,some new.Used is A-OK for panels,hook your meter to it,if it reaches power,no cracks and tight and clean you are set on the cheap for more panels.Ive bough 2000 watts used and would like more but Im in money saving mode so cant right now.


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## Big Dreamer (Aug 6, 2010)

I think you are right. I will pick one and do some testing. 

I checked Craigslist and there is a person that has solar panels for 1.75 per watt and they are 125 150 and 200 watt 12 volt panels so I will see what I can do with that. 

The generator is also a good idea so I will keep my eye open for one as well. A friend had a small portable one awhile back he wanted to sell I will check with him again. I could just skip the solar stuff and get a generator I guess and that would solve the problem all together.


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## mightybooboo (Feb 10, 2004)

Big Dreamer said:


> I think you are right. I will pick one and do some testing.
> 
> I checked Craigslist and there is a person that has solar panels for 1.75 per watt and they are 125 150 and 200 watt 12 volt panels so I will see what I can do with that.
> 
> The generator is also a good idea so I will keep my eye open for one as well. A friend had a small portable one awhile back he wanted to sell I will check with him again. I could just skip the solar stuff and get a generator I guess and that would solve the problem all together.


But the solar will do other things too,and keeps some nice quiet power at hand,very nice at night time.


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## Big Dreamer (Aug 6, 2010)

Oh I would not give up on Solar! I have been studying solar off and on since I was in grade school. That was a Long Long time ago. I am working on a Solar Hot Water system that is almost complete and just adding the solar electric since I have had a panel in the basement for about 6 years I thought it was time to put it out and see how it works. I think the energy prices are going to go up and I have cut back about 800 kWh per month on average. Just seemed to be a good next step to experiment with. If I can wire in some 12 volt LED lighting that might be a good thing as well. Also a ham operator (KD8ENK) and the solar will operate my radios. So I am excited about solar electricity. 

I just hope I can learn enough to be helpful maybe to someone else in the future. You know return the favor.


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## Big Dreamer (Aug 6, 2010)

Well I took MightBooBoo advice and bought the Xantrex Prowatt Sw2000 2000w True Sinewave Inverter. Should be here next week so we will see how it works. 

I have also decided to get another Deka 9C12 battery and a 100 watt solar panel. That is about all the money I have for this project for a couple of months. 

So I hope it is a fairly good start but certainly not an off grid solution. Off grid is not what I am shooting for here anyway. 

Thanks for all of the advice
Gerald


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## mightybooboo (Feb 10, 2004)

WTG Gerald,I think you will be mighty pleased with your system,and as everyone here will tell you,once you start you wont stop.Youre on your way now.Soon you will buy this,add that,and get a real good grasp on what you can do.Small systems sure are easy.

Congrats.


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## Big Dreamer (Aug 6, 2010)

Well I just thought I would give an update on the inverter that I chose. It has worked out very well and I have used it for a few things like soldering, charging batteries for the cordless drill and running a pc and monitor. I am getting ready to wire in an outlet to run my PC in the house and a few other items. I did test it with one battery running my pellet/corn stove and it did run for 4 hours and the battery voltage only dropped to 12.2 volts then I stopped the test because it was getting late. Believe it or not it has exceeded my expectations. If I can get the pictures to load I have a snap shot of the scope trace and it is very very good and very clean. I did load it with a Weller soldering iron because it was handy. The Xantrex Prowatt Sw2000 2000w True Sine wave Inverter in my opinion is well worth the 334.00 that I paid.


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## Rick (May 10, 2002)

Big Dreamer said:


> Well I just thought I would give an update on the inverter that I chose. It has worked out very well and I have used it for a few things like soldering, charging batteries for the cordless drill and running a pc and monitor. I am getting ready to wire in an outlet to run my PC in the house and a few other items. I did test it with one battery running my pellet/corn stove and it did run for 4 hours and the battery voltage only dropped to 12.2 volts then I stopped the test because it was getting late. Believe it or not it has exceeded my expectations. If I can get the pictures to load I have a snap shot of the scope trace and it is very very good and very clean. I did load it with a Weller soldering iron because it was handy. The Xantrex Prowatt Sw2000 2000w True Sine wave Inverter in my opinion is well worth the 334.00 that I paid.



BD : Keep in mind that the 12.2 V reading when it got late is as low as you want to drain them. I drained my secondary Marine battery bank below that 2 years ago to maybe 11.8 a few times for a day or 2 until a charger came in the mail. They are 4 or 5 years old and won't hold 100 per cent charge for long. They still work pretty well though - I thought I'd make sure you knew that was the limit. Fuse your panels on the positive side to protect them.


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## trkarl (Dec 15, 2009)

That is a nice clean looking wave. Is that a scope you own? I would like to get one some time. What kind/model is it?


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## Valleyguy (Jan 5, 2011)

Nice scope shots Big Dreamer, thanks for the update. I'm also curious what scope you are using, looks nice.

Have you tried a non-linear or inductive load? That would be the test for wave distortion. 

Rick


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## Big Dreamer (Aug 6, 2010)

I was keeping a pretty close eye on the battery voltage. It went to 12.4 as soon as I switched the house power back to the stove.

I wish it was mine. The scope belongs to work I was doing some field test and had it with me so I figured I would just test my inverter out while it was here. 

It is a Tektronix TDS3054B. It is a 4 channels, color monitor and portable battery operated or AC unit and work really well.


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## mightybooboo (Feb 10, 2004)

Thanks Dreamer for the update,that is some clean power!


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## Calvin Wiles (May 14, 2008)

The best inverter for the money that I have found is the ones that Sigler Music use for their instruments. I bought one, and a Friend of mine bought one, and they are serving our needs well.


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## mightybooboo (Feb 10, 2004)

Calvin Wiles said:


> The best inverter for the money that I have found is the ones that Sigler Music use for their instruments. I bought one, and a Friend of mine bought one, and they are serving our needs well.


Couldnt find anything at site,have a link?


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## Big Dreamer (Aug 6, 2010)

I think he is talking about the OSP inverters. I went to http://www.siglermusic.com and did a search for inverter it then took me to Ebay and the OSP inverters. They do have a 1500 watt pure sine wave for 225.00 with shipping or 3000 watt modified sine wave for the same price. I did look at those before I bought mine but I could not find a lot of information on them and I just wanted a good pure sine wave. They do look like a very nice unit.


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