Xantrex Inverter Frustrations

lyonkster
lyonkster Registered Users Posts: 10 ✭
in General Solar Power Topics #1
New poster here, would appreciate some help with inverters.

I bought the Xantrex SW2000 inverter for our fifth wheel, rated at 2000W continuous and 3000W surge. I was a bit hesistant when buying, as I saw 4 reviewers on Amazon complaining that it does not deliver anywhere near that power, but I was hoping against hope that maybe they didn't hook theirs up correctly :).

Sure enough, after hooking it up to our fully charged dual batteries with #2AWT cable, I was able to power my 5A variable speed drill, and a 7A drill, but neither the 13A circular saw nor the 1500W microwave would even come on. So I am guessing the inverter can put out around 10-12A, i.e. 1200-1400W, but nowhere near 2000-3000W rating. So looks like the Amazon reviewers were right.

My questions are, has anyone here experienced the same problem with this inverter? It was about $100 cheaper than all other inverters in that size and type (TSW), so maybe that should have been a warning?

Also, what other models would you guys recommend in this range? Sunforce 2500? Aims 2000?

Thanks in advance!
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  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    #2
    Re: Xantrex Inverter Frustrations

    I don't have personal experience with this particular model, but running a 2000W inverter on just 2 batteries is probably your problem. 2Awg cables should be OK assuming they are not very long (<10ft) but I would say a couple more batts are in order to crank that kind of power.
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  • lyonkster
    lyonkster Registered Users Posts: 10 ✭
    #3
    Re: Xantrex Inverter Frustrations
    solarix wrote: »
    I don't have personal experience with this particular model, but running a 2000W inverter on just 2 batteries is probably your problem. 2Awg cables should be OK assuming they are not very long (<10ft) but I would say a couple more batts are in order to crank that kind of power.

    Thanks, I was wondering if perhaps that was the problem. (The cables are just about 10 ft total loop, BTW).

    But do you mean the battery pack is not adequate due to A-hr capacity, or due to amperage? I realize that with these two batteries and 230 A-hr capacity, I cannot be drawing 2000W for more than a few minutes, but that is all I want (maybe run my circular saw to cut a 2x4, heat up a cup of coffee, etc). Not hoping for a prolonged duty, for sure.

    Or do you mean that even for a very short duration the two batteries may not be able to supply the amperage? I do not know if there is a limitation of how much current a battery can supply, maybe that is the problem? I didn't see anything in Xantrex's literature to imply such a limitation.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #4
    Re: Xantrex Inverter Frustrations

    Roughly for Flooded Cell Batteries:
    • C/20 to C/10 -- recommended current flow (efficient, long life)
    • C/8 -- maximum continuous current flow
    • C/2.5 -- maximum surge current (few seconds)
    So, for your 230 Amp*Hour 12 volt battery bank:
    • 230 AH * 1/10 = 12.6 to 23 amps "average current"
    • 230 AH * 1/8 = 29 amps "max continuous current"
    • 230 AH * 1/2.5 = 92 amps "surge current"
    Or, in AC power assuming 11.5 volts minimum voltage and 0.85 efficient inverter:
    • 230 AH * 1/10 * 11.5 volts * 0.85 = 225 watts "average power"
    • 230 AH * 1/8 * 11.5 volts * 0.85 = 281 watts "max continuous power"
    • 230 AH * 1/2.5 * 11.5 volts * 0.85 = 899 watts "surge power"
    You could use Concord AGM batteries for much higher surge current -- but they are much more expensive batteries and still would not give you extra AH capacity--just surge current support.

    With 2 AWG wiring, 180 amp surge current (to support ~1,800 watt surge), 5' one way run, and a voltage drop calculator:
    • 0.3 volt drop... Should not be a problem with wiring drop
    These high currents (and typical smaller 12 volt battery bank AH capacity) is why we usually say that 1,200 - 2,400 watts is about the maximum you would want for a 12 volt battery system...

    For example, 12 volt system operates down to 10.5 volts, 0.85 efficient inverter and 1.25 NEC safety margin for wiring/fuses/breakers:
    • 1,200 watts * 1/0.85 eff inverter * 1/10.5 cut out voltage * 1.25 safety factor = 168 amp minimum rated wiring/fuse/battery bank
    • 3,000 watts * 1/0.85 eff inverter * 1/10.5 cut out voltage * 1.25 safety factor = 420 amp minimum rated wiring/fuse/battery bank
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • lyonkster
    lyonkster Registered Users Posts: 10 ✭
    #5
    Re: Xantrex Inverter Frustrations
    BB. wrote: »
    • 230 AH * 1/2.5 = 92 amps "surge current"
    • 230 AH * 1/2.5 * 11.5 volts * 0.85 = 899 watts "surge power"

    Bill, thanks, this is the first time I saw actual numbers associated with inverter sizing. So it sounds like my battery bank is not good for more than ~ 1000W.

    What I don't get is that before choosing this inverter, I called Xantrex, Aim, and InvertersRUS and specifically asked them about this, and all three sources said that there is no real limitation on current drawn from a battery, and that for my battery bank a 2000W inverter would be perfectly fine. So it's a bit odd that all three of them would be so far off.
    These high currents (and typical smaller 12 volt battery bank AH capacity) is why we usually say that 1,200 - 2,400 watts is about the maximum you would want for a 12 volt battery system..

    So you are saying that I could get 2000W out a 12V battery bank, but would need a much larger bank than what I have now, correct?

    Thanks for your help!
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #6
    Re: Xantrex Inverter Frustrations

    You are very welcome.

    The numbers we try to use are fairly conservative and based on experience from people posting their experiences here (both end users and solar RE designers).

    While it is certainly possible to get more power from smaller battery banks; for the folks that want their systems to be reliable for years into the future (off grid cabins, homes, RV's, etc.), we try to recommend relatively bullet proof rules of thumb that will work for everyone.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • vcallaway
    vcallaway Solar Expert Posts: 157 ✭✭✭✭✭
    #7
    Re: Xantrex Inverter Frustrations

    My own experience is batteries and wires both make a difference.

    I have two 2/0 3' cables powering the inverter for my home. The generic 8d battery I currently have connected can provide the current to max the inverter. The Trojan 200 Ah battery I was using would not. Trojan confirmed the battery I have was not designed to do that. It does however work great in my RV where I don't max it out.

    I also could not max the inverter with a single cable. Adding the second cable solved my issue.

    Also, the installation manual for my Xantrex 2k inverter recommends using 0 gauge wire. I use 2/0 mainly because I can pick those up at any auto parts store.

    I'm no expert by any means, but I've found out over the years it is better to have too much wire than not enough.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #8
    Re: Xantrex Inverter Frustrations

    yes, battery capacity and wire sizing can stop the power from being delivered if inadequate. you have a voltage drop on the wire plus a voltage drop on the batteries themselves when heavily loaded and can cause an inverter to kick out due to too low of voltage. remember that 200a at 12v will roughly boil down to 20a at 120v. this is all of the battery capacity and then some at a 1 hr rate. the batteries aren't meant for that kind of discharge.

    now if this is the prowatt sw2000 then know that it is not a 2000w rated output inverter as it is more around 1800w. even if not the prowatt, it still may be the same basis of circuitry and parts and be lesser on output. few actually run 2000w of inverter continuously at 12v because of the troubles it causes with the batteries the associated higher losses. most just want intermittent headroom, but that is why surge power is listed and should not be confused with continuous power and i'm not saying that this is what you are doing, but manufacturers sometimes stretch and intermix things.

    either or both cases could be problematic for your goals.
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  • lyonkster
    lyonkster Registered Users Posts: 10 ✭
    #9
    Re: Xantrex Inverter Frustrations

    Thanks for the great replies. This is in fact the ProWatt SW2000, which is rated at 3000W surge and 2000W continuous. But most reviewers at Amazon complained that in did not deliver anywhere near that power - yet when they switched to others (such as the Sunforce 2500W) they were able to get the full power. So that gave me some suspicions about this particular inverter.

    I understand the comments about having an inadequate battery bank for the full power rating. I am just wondering if I should abandon the whole inverter idea altogether, get a smaller one (but there really isn't that much cost savings anyway), or get more batteries in the bank. The latter concerns me because I can see myself starting to go down the path of needing more solar arrays, then more charge controllers, and all that has $$$$$ associated with it :).

    The way we use this fifth wheel is that it sits in the desert all year long, and we come there for a day or sometimes overnight, maybe a total of 5-10 times a year. So 99.9% percent of the time (estimated :) ) the batteries are unused. It's just that I was intrigued by the idea of being able to occasionally fire up a circular saw, or an air compressor, or a microwave. But we are truly talking several seconds or a couple of minuters at most, maybe 3-4 times a year. So I find it hard to justify investing a lot more $$ into the system just to be able to do that; maybe I am better off getting a small (gasp) generator?

    Thanks for the thoughts!
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #10
    Re: Xantrex Inverter Frustrations

    You will find that most of us here are practical old 'coots... And while we have various opinions about what "going green" means--Normally we all agree that conservation is the key to happiness regarding off-grid (and even on-grid power).

    In your case, your current power usage pattern is not really very good for solar... 10-20 days a year is very difficult to justify powering everything with solar PV and a battery bank. Solar can be cost effective when you are using it 9+ months of the year.

    In your case, I would keep the solar system small--Look at something like the MorningStar 300 Watt TSW inverter (has a low power search mode which allows you to turn on and off >6 watt AC loads as you need them). Being TSW, it will be very friendly for all of your small electronic loads (wall mount transformers, cell phone chargers, etc.).

    Then for you larger loads... Ideally, to power a skill saw, run the microwave, quick charge the battery bank--A Honda eu2000i 1,600 watt genset. If you need less power, the eu1000i 900 watt is smaller and lighter. Very quiet and fuel efficient with smaller loads.

    Solar wise, just enough solar panels to keep the batteries topped off (or equal to your daily loads)... Use the small genset in the morning to top off the batteries with a couple hours of run time.

    Otherwise, get a cheap/large MSW inverter for the few times you need to power your saw and/or a cheap 3kW genset (noisy, sucks fuel like no tomorrow with light loads) for a 1/3rd or less the price of the Honda.

    You also have alternatives--Yamaha (and some conversion kits for Honda and others) have propane compatible gensets (if you have a large tank on site). Probably not quite as fuel efficient--but may be a better match for your needs/fuel availability.

    All depends on your needs... Having an expensive setup unattended ~340 days a year--I would not be too interested in leaving a lot of expensive equipment lying around.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #11
    Re: Xantrex Inverter Frustrations

    i think i'll agree to go with the generator. as bb said a small pv can be used to give the batteries a float charge. i would get a small charge controller to prevent overcharging. many will say you won't need one, but a pv will continue to impress its voltage until it reaches an equilibrium with the losses of the batteries. it could slow cook the batteries and even boil out some electrolyte in the many months of your absence. a cheap controller is far cheaper than replacing any batteries. the rate of a float charge can be 1 to 2 % of the ah capacity.
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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #12
    Re: Xantrex Inverter Frustrations

    lyonkster,

    If you are really bored you can search my previous posts but my opinion is ...

    ... the ProWatt inverters don't provide enough surge capacity for their rating. I bought a 2.0kw when I installed my Sanyo mini-split to replace a 1.0 ProSine... the surge from turning on 100w of lights would trip it off when it was running at 1850w. Yeah, I know that exceeds the rating. But I'd have expected the momentary surge to not be a problem. The ProWatt WAS inexpensive.

    I didn't whine [much] about it, I just replaced it with a Magnum 2800w unit and have had no problems since. I did not want/need charging capability but now have it anyway, unused.

    So I put the ProWatt 2.0 in my RV, replacing another ProSine 1.0, thinking it'd be nice to use the microwave on occasion. Understand, I've had no problems with the ProSines ever (but I didn't expect them to power the Sanyo or the microwave). Xantrex -- newer, bigger inverter -- must be better.

    Every time I've tried to use the microwave, the ProWatt has tripped off. It's a SMALL RV microwave! Nothing else running. Batteries charged, hefty cables to the inverter.

    Buying the ProWatt was only a $350 error. Not a big deal, all things considered.

    Phil
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  • lyonkster
    lyonkster Registered Users Posts: 10 ✭
    #13
    Re: Xantrex Inverter Frustrations

    Phil, thank you, your experience with the SW2000 seems to be exactly in line with what I found, and with what reviewers said on Amazon. Like you said, $350 is very cheap for a 2000W TSW inverter, so I guess you do get what you pay for.

    I also agree with Bill that the idea of putting in thousands of dollars into a solar electric system for a trailer that sits vacant (and vulnerable to theft) 350 days out of the year is not all that good. I like our current setup of two batteries, one small solar panel, and a charge controller - it works perfectly fine for what we want. I might consider a much smaller inverter, but I do not want to go down the path of having to upgrade batteries, charge controllers, and solar panels - that gets really expensive really fast, and it's hard for me to justify it.

    So maybe a small inverter and a small generator is the best way to go.

    Thanks for all the thoughts!
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  • bmet
    bmet Solar Expert Posts: 630 ✭✭
    #14
    Re: Xantrex Inverter Frustrations
    PhilS wrote: »
    lyonkster

    Every time I've tried to use the microwave, the ProWatt has tripped off. It's a SMALL RV microwave! Nothing else running.

    That remind me of my 900 watt microwave that Kill-A-Watt shows 13.5 Amps when running.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #15
    Re: Xantrex Inverter Frustrations

    Yep, Power Factor strikes again:
    • Power = Volts * Amps * PF
    • PF = P/(V*I) = 900 watts / (117 volts * 13.5 amps) = 0.57 PF
    There are the "Inverter Microwaves"--I don't remember seeing any details about there PF/VA ratings.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #16
    Re: Xantrex Inverter Frustrations
    lyonkster wrote: »
    So you are saying that I could get 2000W out a 12V battery bank, but would need a much larger bank than what I have now, correct?
    Thanks for your help!

    Well I've got a Xantrex SW 1800 watt 12 volt Pro Sine inverter and am extremely happy with it. Runs water pump, toaster oven, microwave, 9 amp band saw, 12 amp skill saw and 15 amp cut off saw. The start surge on some of these items is huge, yet each one both starts and runs every bit as good as they do on grid power. And that is something I didn't expect. I am actually VERY impressed with this unit, had it shipped into Canada from Sun and Wind, the providers of this form. But, I do have approx 1200 AH in L-16 batteries.

    So to me, it does sound like either you have a battery problem, or a poor connection at, or between the batteries, or inverter. If you have a good volt meter, you can check the battery voltage under full inverter load, both at the battery terminals, and at the inverter.
    That should give you a very goof idea of what's going on.
    Good luck.
    By the way, when I first got it, just to make sure it was working OK, I hooked it up with jumper cables and my heart fell, it wouldn't even start a 1/4 hp motor under no load. Finally I checked the input voltage at the inverter, and realized there was a far bigger problem with my temporary connections than I realized.
    OOPS, I see too that you have the Prowatt and I have the Pro Sine.
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  • 2manytoyz
    2manytoyz Solar Expert Posts: 373 ✭✭✭
    #17
    Re: Xantrex Inverter Frustrations

    I have this same inverter.

    The advertising would have you believe this is a 2000 Watt inverter. It's not. Take a look at page 11 of the owners manual, it's only 1800 Watts. Discussed further on page 27

    http://www.xantrex.com/documents/Power-Inverters/PROwatt-SW/975-0529-01-01_Rev-B(PROWatt%20SW%20Inverter%20NA).pdf

    The PROwatt SW Inverter will deliver the following power
    continuously, depending on input voltage and ambient temperature.
    The inverter will deliver more than 10% of its continuous power
    rating for approximately five minutes. The inverter must cool down
    for 15 minutes before it can resume operation above its continuous
    power rating.

    1800W Continuous
    2000W For 5 minutes
    3000W Surge

    I had read the same reviews on Amazon. I also believed the reviewers had too small of a battery bank, and/or too small cable feeding the inverter.

    Here's a test I performed on mine:

    http://www.youtube.com/watch?v=mwuiQYZhGRc

    About a 1500W load. No problems. I hope to get time to connect it to my system this weekend, with 4/0 cable.

    I also put it on a scope - waveform was a nice sinewave as expected.

    As others have mentioned, think your battery bank was too small.

    I have a very quiet Yamaha EF2400iS generator that I sometimes use with my RV. It's the lightest, quiet series generator, capable of running a 13,500 BTU A/C unit solo. Half the weight of a 3000W Yamaha or Honda (70lbs vs. ~140lbs). Also a great generator for emergency power at home.

    Details of the tests I've run with this generator at this link: http://www.2manytoyz.com/yamaha2400.html
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  • Adam1980
    Adam1980 Registered Users, Users Awaiting Email Confirmation Posts: 1 ✭
    #18
    lyonkster said:
    New poster here, would appreciate some help with inverters.

    I bought the Xantrex SW2000 inverter for our fifth wheel, rated at 2000W continuous and 3000W surge. I was a bit hesistant when buying, as I saw 4 reviewers on Amazon complaining that it does not deliver anywhere near that power, but I was hoping against hope that maybe they didn't hook theirs up correctly :).

    Sure enough, after hooking it up to our fully charged dual batteries with #2AWT cable, I was able to power my 5A variable speed drill, and a 7A drill, but neither the 13A circular saw nor the 1500W microwave would even come on. So I am guessing the inverter can put out around 10-12A, i.e. 1200-1400W, but nowhere near 2000-3000W rating. So looks like the Amazon reviewers were right.

    My questions are, has anyone here experienced the same problem with this inverter? It was about $100 cheaper than all other inverters in that size and type (TSW), so maybe that should have been a warning?

    Also, what other models would you guys recommend in this range? Sunforce 2500? Aims 2000?

    Thanks in advance!


    Hi there,


    I know it's frustrating ,  dont try to get near100o watts , you will get E03 or E04  if you cross ,
    no mattery if  you are running a motor or light bulb,
    Xantrex tech support can tell you to shut it down for two hours ! and try it again
    It;s a chip Chinese inverter

    Xantrex Expert Guy

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #19
    Adam,

    That is an 8 year old post--And the original poster is (probably) never going to see your comment.

    And there is a lot more to worry about with a "higher" power installation (amp*hour rating of battery bank, type of batteries, length and gauge of power cables, type of AC load) than just the inverter itself.

    I think it best to let this thread rest.

    If you have questions or experiences you would like to discuss here--Please feel free to start a new thread (discussion).

    Sincerely,
    -Bill "moderator" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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