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Boatycall's avatar
Boatycall
Explorer
Sep 09, 2015

Running roof air off solar, a Honda EU1000, and batteries

My goal - be as quiet as possible when boondocking, while still having all the creature comforts. Even a 13.5k BTU roof air. But on really hot days, even my 600 watts of solar won't match the load. But a new type of inverter has come out that will solve the problem.

As a lot of you know, I'm an Electrical Engineer by day, TC'er by weekend. I just had a nice long conversation with some very helpful folks at Magnum Energy. That made me decide to get a new inverter.

It's model number MSH3012, a 3KW pure sinewave inverter, with built in 125amp DC charger, built in transfer switch - but best of all - their "Hybrid Technology". Oh, and Made in USA, not far from me in Everett WA, literally right across the street from the home of the Boeing 747.

So - what this 'hybrid' thing does - plug in your generator, ANY size. Tell it the size of the generator on the control panel, eg, 1000 watts (or 8 amps). Or even dial it down to 5amps so the gen stays at a lower/quieter level. It will match the generator's sinewave, then supplement it when needed--just like when you parallel two Honda generators. When your roof air kicks on, it will use the generator for all it's worth, and supplement it off battery up to the inverter's rated 3KW. When your roof air cycles off, it senses the load vanished and goes back to using the generator to charge the batteries.

So, small generator can run big roof air. In between 'on cycles', it will then use the gen to bring the batteries back up.

And I thought my Xantrex Prosine 2.0 w/100amp charger was the shiz-nit..... It CAN run my roof air all on it's own, but not this hybrid charge-supplement thing.

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  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Sep 10, 2015
    The heat index here today was 111F. Overcast. And a neighbor said his 7.0 amp panel was developing 1.8 amps at noon . 93F now not a breath of air. I could only hope for an inexpensive way to keep cool. This "house" has 1/2" of plywood between it and eternity. If these Greenhouse Blowhards want to do something constructive let them devise a way to manufacture 2" rigid foam board for price 2,000,000,000 people can afford. China has stupendously altered the face of power generation (gee why is there now ZERO) talk of grid overload and brownout? It ain't coincidence folks. Do the same with insulation and suddenly electricity demand would plummet. RV insulation R values suck. A lot better than they were twenty years ago but they are still awful. Quicksilver has 2" of the most expensive closed cell foam that was available in the 80's yet if the sun hits it I am awake by 0800. So it sits in the shade. An example of a paradox.
  • hbski's avatar
    hbski
    Explorer
    Sep 10, 2015
    Huntindog wrote:
    hbski wrote:
    Huntindog wrote:
    ......On edit... I just googled it $2224.00 !! Holy smokes.......


    try imarineusa dot com $1575, not a whole lot more than a quality standard 3000W pure sine inverter......in fact less than some of them.

    peace and quiet.......priceless
    I just tried it. It's not there. I even searched the site using the model #.. No hits.
    They do have a number of other Magnum products at pretty high prices though


    funny, cause I find it every time

    look under manufacturers.....scroll down to msh3012m and then add to cart to see actual price

    MSH3012M
  • CJW8's avatar
    CJW8
    Explorer
    Sep 10, 2015
    No need to apologize to me. Your original title was an attention grabber. I knew it was misleading before I read it but wanted to find out what it was all about. Not the first time we have had a check out stand tabloid title and no one cared. Why the big deal now?

    I'd have a hard time paying that much for an inverter but I stand by my scenario. I'm at 5000 feet and my main gen is broken. I have to rely on my Champion 3500/4000 for my air because it is 90+ outside. But under these conditions my Champion will not start my 15K air con. I know, I've tried it. This inverter would get me over the hump for the less than one second of locked rotor current. Then the air con goes to normal run current which is less than half of what my Champion is capable of. There is even some overhead to recharge the battery. If not, I could limit my 40 amp Xantrex TC2 to 30% output. There will be no cycling of the AC as under these conditions, it is going to run continuously. The Champion is not fully loaded as some have implied and thus is not being over worked. Since I have 500 watts of solar, if the sun were shining, I'd shut the TC2 off and let solar do it's thing.
  • Boatycall's avatar
    Boatycall
    Explorer
    Sep 10, 2015
    hbski wrote:
    try imarineusa dot com $1575, not a whole lot more than a quality standard 3000W pure sine inverter......in fact less than some of them.
    peace and quiet.......priceless

    I got it from there after talking to Magnum. The guys at Magnum said they are a good dealer, but get their hands slapped for advertising prices lower than "Manufacturers Advertised Pricing". And Magnum does consider them an authorized dealer, so 3-year warranty is good.

    At the time I got it, it was saying 'last one'. I'm sure they'll get more.

    Here's a write up on one that I used in my decision to get one--
    Wheelin-It RV Review
  • Boatycall's avatar
    Boatycall
    Explorer
    Sep 10, 2015
    Huntindog wrote:
    Not unfair at all. You just edited your OP to make it seem so. From the OP, you got the responses that you deserved


    You know, at first, I was ticked. And ticked is the only term I can use that won't get ****'d out by the filter. But I thought about it, and you're right--I had a misleading title making thinking people could do this with nothing more than a little honda gen.

    So, here I am saying publicly, sorry, shouldn't have labeled my post that.

    I just thought it was real cool that I found a product I could get that if I couldn't run my roof air off solar alone, I wouldn't have to forgo solar and drag some huge gen or a pair of gens with me. I can supplement my solar with this when needed.

    And as others have spotted in a previous post, I did get it from iMarine. Worth noting - you have to buy a controller/panel separately, that's another $140.

    Mine should be here next Wednesday. Ironically, I'm going boondocking this weekend where it's supposed to hit almost 100 degrees.

    But as far as the noise of the roof air itself goes - it's an almost brand new roof air 12 feet up in the center of my TC - honestly, you can't hear it from ground level. I have, on occasion, had to go inside my TC to make sure it's still running off solar ok.
  • Huntindog's avatar
    Huntindog
    Explorer
    Sep 10, 2015
    Boatycall wrote:
    I enjoy the piece and quiet of the great outdoors.

    Only after that will I need the help of a small genny.

    I use them only as a last resort when boondocking. I prefer piece and quiet, while still having as many creature comforts as I can. And while a 6500 is pretty quiet, a 1000 is even more so. But then again, solar makes even less noise.

    Totally illogical.
    When running the AC, it makes so much noise that you can't hear the generator.
  • Huntindog's avatar
    Huntindog
    Explorer
    Sep 10, 2015
    hbski wrote:
    Huntindog wrote:
    ......On edit... I just googled it $2224.00 !! Holy smokes.......


    try imarineusa dot com $1575, not a whole lot more than a quality standard 3000W pure sine inverter......in fact less than some of them.

    peace and quiet.......priceless
    I just tried it. It's not there. I even searched the site using the model #.. No hits.
    They do have a number of other Magnum products at pretty high prices though
  • hbski's avatar
    hbski
    Explorer
    Sep 10, 2015
    Huntindog wrote:
    ......On edit... I just googled it $2224.00 !! Holy smokes.......


    try imarineusa dot com $1575, not a whole lot more than a quality standard 3000W pure sine inverter......in fact less than some of them.

    peace and quiet.......priceless
  • road-runner's avatar
    road-runner
    Explorer III
    Sep 10, 2015
    There's some shared responsibility here IMO. The original thread title sets the expectation that you had figured out how to beat basic laws of physics to run the air conditioner from the eu1000i with no other power source. Then after reading the details I'll say for myself that I felt deceived. The revised thread title fixes that issue. Getting past the emotional reaction, it's clear that you have set up a system that provides a way for running the air conditioner without the need for as large a generator as would otherwise be needed. With my RVing profile this system would be a poor choice, yet I can see that for another situation it could be a great choice. I don't think the capability is new because it has been offered by Victron inverters for at least a few years. You provided the valuable information of an alternative inverter and a real-life use report to go with it. Instead of just taking in the technical information, the "kill the messenger" posts follow, pronouncing the idea as infeasible, stupid, doesn't work for me, etc. Instead of just ignoring something they possibly don't understand or doesn't apply to them, these posts have to dump on it. If it's any comfort, you haven't been dumped on nearly as much as the forum members who run an air conditioner with an eu2000i as the sole power source.
  • christopherglen's avatar
    christopherglen
    Explorer
    Sep 10, 2015
    I have a 55 amp charger set at 14.4 volts intended to run off a Costco 2000 inverter generator. My idea was to supplement my existing batteries and existing 3kw inverter. I do not yet have solar on the trailer, but when I do the plan is to do similar to you - except with double conversion VS sync AC like you. Your syncing to the generator makes you somewhere in the 30% more efficient. You already have 600 watts of solar, which can easily make up for the generators shortfall on the cycling AC, and likely support most of the other loads when it is not. While the cost of the inverter is steep VS the cheapies, you already have everything else installed and operating - I would consider this project more of a way to add 12-14 hundred watts of solar without the roof real-estate when loads require it VS how to make solar back up an undersized generator.

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