Inverter Gurus- looking for my next “perfect” inverter

100 Proof100 Proof Registered Users Posts: 2

Calling all Sages!

I am an RV weekender, not a full-timer. I’m looking for my next “perfect” inverter. For the last 5+ years, I have thoroughly enjoyed my Morningstar SureSine. It has been reliable, silent, low idle draw, and just… perfect! But my needs are evolving, and I need to step up to something a little larger. I want to accomplish 2 primary goals:

Goal #1- I would like to run a 5,000 Btu window air conditioner for 2 weeks in the summer on a dry lakebed during the afternoons. The intent is to only run it when the panels can furnish 100% of the power. According to my Kill-A-Watt, it draws about 465 W once it gets rolling. I tested it on my friends KRIËGER 1100 W MSW unit and it seemed to handle it OK.

Goal #2- I would occasionally like to run my Microwave. It is labeled as a 900 W unit, but I haven’t had an opportunity to run it through the Kill-A-Watt yet.

Following are my wants, not needs:

-        I would like an inverter that is not “just big enough”, as I believe that not challenging the limits is valuable for things like longevity and reliability.

-        I would prefer a low frequency inverter for the startup margin in case I run inductive loads down the road.

-        I would prefer a TSW over a MSW, but I’m not married to this as I can keep my SureSine if needed for the more sensitive stuff I power.

-        I would like something with a low idle draw.

-        I would prefer to spend around $500 or less but recognize that may not be realistic.

My system is currently configured as follows:

-        3, 157 W, 75 Vmp TransformSolarTM panels permanently mounted on the roof, and 2 more to be temporarily mounted in the desert. (That was not a mis-type. They really are 75 Vmp each. These are odd ducks that are no longer manufactured.)

-        Connected by <10 feet of 10g wire to a Morningstar MPPT-45 charge controller.

-        Wired via <8 feet of 4g cable to a series/parallel bank of 4 208AH GC2s. The battery bank, Trimetric shunt, and 400 A catastrophe fuse are all wired up with 2/0.

-        The SureSine is connected with ~2 feet of 2/0 cable and the new inverter will have the same. There are 3 dedicated outlets hardwired to the inverter in convenient locations.

Even though I don’t need the charger or transfer switch, I really like the AIMS PICOGLF25W12V120AL ( which can be had for ~$500. What kills me about it though is the idle consumption of 55 Watts and the Peak Efficiency of 88%. I suppose I could keep my SureSine and only turn this one on when I need it though. 

So, what are your thoughts? What is out there that I haven’t seen yet? What would you do?


100 Proof


  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    FWIW... personally, I'd stick to "name" brands such as those sold by our hosts.  Not needing charger or transfer switch, you might consider something in the Samlex line, which seem fairly well regarded around here.

    For a microwave, I'd suggest a PSW as not optional.  I made the mistake of putting a MSW unit on my boat for the nuke, and notice a marked difference in heating power between shore power and the inverter (which has plenty of wattage to run the small microwave).  The AC motor will likely run cooler on PSW as well.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • PNW_StevePNW_Steve Registered Users Posts: 79 ✭✭
    I have installed a number of Samlex psw inverters in mountain top communications sites in 2007 or 2008. I talked to the gentleman who took my place when I left and as of February of this year they are all still working. 

    That said,  Samlex is about the low end that I will use.  For my own use I am partial to Xantrex and Trace. 

  • 100 Proof100 Proof Registered Users Posts: 2
    What do you think about the Xantrex Freedom X?
    It has a 2x surge for a full 2 seconds. That would largely address my inductive startup load concerns. Does this unit have a decent track record?
  • PhotowhitPhotowhit Solar Expert Posts: 5,976 ✭✭✭✭✭
    100 Proof said:
    What do you think about the Xantrex Freedom X?
    It has a 2x surge for a full 2 seconds. That would largely address my inductive startup load concerns. Does this unit have a decent track record?
    First I've seen of it! I would guess a new product. Manual is copyright 2017-2018.

    Xantrex tends to a reliable company and Northern Arizona Wind and Sun will sand behind it.

    I like that it has a somewhat extended environmental range without 'derating'. It sound like it might be a good choice in a desert environment. Might check to see above those temps...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former, 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Even if the inverter can provide a 4kw surge, the cables and batteries have to be able to deliver that power too.
    4kw @ 12V is going to suck 333 Amps .  That needs some heavy cables, and batteries that can deliver that power, or you will be fooling yourself thinking it would work when installed.    Short, heavy power cables or the inverter will see lower voltage and shut down.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

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