New Off Grid Inverter Charger

[Westbranch]

there is an interesting discussion on NAWS about using a small inverter to 'fool' a larger one into thinking the smaller one was the Grid.  http://forum.solar-electric.com/showthread.php?24565-Paralleling-inverter-chargers-with-generator-quot-boost-quot-quot-support-quot-function

Post #5 is most interesting in that 'Coot talks about an inverter that could be 'modular' as we have talked about earlier.  Here is the key paragraph, to me:

It would theoretically be possible to build a modular inverter with a 'control unit' that can operate and sync multiple 'power units' much the way stacking inverters do, only without the redundant control units. You could then have flexible sizing of, say, 500 Watt increments and/or the ability to turn on only as much power capacity as needed. But would it be practical? The money spent on the more complex design could simply be used to up the system power capacity to handle greater losses from a conventional inverter.

[Robin]

It was fun reading through all the posts here. A lot has changed since we started the inverter project. Let's suffice it to say that most of the questions and suggestions will turn out to be pretty much what is wanted. There will be a bunch of inverters, not just one.
We still have a ways to go, but you can expect more real news about the project in a few months. The MidNite Inverter (s) are not going to be  like anything on the market. We are a long ways off from having a shippable product, so hang in there. Perhaps we can start a beta test list for those of you who might want in on the fun, but give us some time before doing that.

[tecnodave]

Very interesting thread on little inverter/big inverter.

As boB pointed out to me there is a model which has a smaller inverter inside. ( We were discussing the Dynamote Brutus inverter)


This from the manual for the Vanner Tru-Sine 4500

<quote>
The inverter consists of two sine wave inverters built in one unit. A "low power" high efficiency 70 watt inverter supplies power for the small loads. The "high power" 4500 watt main inverter supplies power when AC loads over 70 watts are present.
<end quote>

This inverter is apparently the evolution of the Brutus Tru sine as Vanner bought Dynamote.

interesting concept

td

[zoneblue]

Well hopefully the takeaway for midnite here, is,  WE WANT LOW TARE. Hint. Hint. Why make solar energy and just thow it away. And we arent talking about sleep mode, which is next to useless, either.

[Surfpath]

I am glad to see that the Midnite inverter discussion has resurfaced.

With the success of the wee Kid it's high time that Midnite enter the 'wee' inverter world.

I vote with Nigel about the availability of a 50hz model.  Here's why:  Like many small house/cabin offgridders around the world, I have moderate to low consumption (3kwh/d), but a hulking hungry OB inverter that sits there turned on all day only for my fridge to 'surge.'   

Given my other appliances, if it wasn't for that fridge surge I'd be fine with a much smaller inverter (OK, I'll run the 800w washing machine on a new Honda briefcase generator - that I need anyway).  But wait.....

Inverter fridges are now very much available on the international 230V market (Animatt, another midnite user who posted on this same thread earlier, is running his inverter fridge quite easily using a MS Sursine PS300):  See link FMI:

http://forum.solar-electric.com/showthread.php?24550-suresine-running-unmodified-refridgerator%28inverter%29

.....so

Us 50hz 230v folks are primed for these smaller, less power-hungry, pure sine inverters (a little bit bigger than the MS 300 - all due respect Morningstar - and in the 24/48v battery bank range that the MS300 doesn't account for).

Can I be a beta tester please??
-Surfpath 

[dgd]

I am glad to see that the Midnite inverter discussion has resurfaced.

With the success of the wee Kid it's high time that Midnite enter the 'wee' inverter world.
.....so
...
Us 50hz 230v folks are primed for these smaller, less power-hungry, pure sine inverters (a little bit bigger than the MS 300 - all due respect Morningstar - and in the 24/48v battery bank range that the MS300 doesn't account for).[/b]

High time maybe but it would seem unlikely this year or even next, no info on possible MN inverters is available and we are only told MN are listening to suggestions.
In any case there is a plethora of small to 1KW pure sine wave inverters already available. Leaving the chinese multiple inverter offerings aside there are many europeane and Australasian high quality sine wave inverters (230v 50Hz) with extremely low tare and high conversion efficiency, available right now.
My personal favourite is the Oz SEA Bolero 1.1Kw 24v (1kw 12v) pure sine, well built and just keeps working flawlessly 

dgd

[Robin]

dgd is correct. There are plenty of inverters out there now.
That doesn't mean that they won't be obsoleted by something more advanced someday.
The Dynamote Brutus with the small co-inverter was done due to the horrible high tare loss of the regular Brutus. It was a compromise design for sure. When we got tare losses down to 16 watts on the Trace 4000W SW inverter, the co-sine inverter became obsolete. You all are kinda sorta on the right track though talking about methods to achieve low idle. that is just one of many things that would be desirable in a new inverter Tee, Hee.

[Highflyer]

Any update Robin?

its been nearly 8 months.

[dgd]

Now this is a real  inverter transformer, a very interesting construction series of postings on otherpower from Oztules.
http://www.fieldlines.com/index.php/topic,148717.0.html

I have two of these $99 Inspire grid tie inverters that were sold cheap on EBay when the company went belly up. Another project in the planning 

This is something I would expect to see in the new Midnite power inverter,6Kw, 8kw surge BIG Toroid with a few (metric) Kgs of solid copper. Given MNs expertise in winding those inductors for the Classic then I expect this would be a 'stroll in the park'
Can we expect to see something of the MN inverter more sooner rather than later?  or should I start unwinding all that copper and tape?

dgd

[mike90045]

Now this is a real  inverter transformer, a very interesting construction series of postings on otherpower from Oztules.
http://www.fieldlines.com/index.php/topic,148717.0.html

I have two of these $99 Inspire grid tie inverters that were sold cheap on EBay when the company went belly up. Another project in the planning 

This is something I would expect to see in the new Midnite power inverter,6Kw, 8kw surge BIG Toroid with a few (metric) Kgs of solid copper. Given MNs expertise in winding those inductors for the Classic then I expect this would be a 'stroll in the park'
Can we expect to see something of the MN inverter more sooner rather than later?  or should I start unwinding all that copper and tape?   dgd   

Well, that's the slick way to do it.   Thanks for the insight

[SolaRevolution]

2 or 3 cents here:

I'd like to see a small inverter sized with consideration of a whole system, including matching to a CC and a convenient PV array,  BOS equipment, available generators, common battery sizes... the whole works.

The KID CC  is an awesomely capable little whelp.  Matching it with a fairly "dumb" and little inverter charger can make a very nice little system.  The trouble is most of "dumb little" inverter chargers are 12 volt and just a touch too small for many applications. At 12 volts, the KID is limited to <500 Watts of PV.

Now, if you guys made a small (same physical size as the MMS) 24volt, 1800w, 120vac inverter/charger, match it with a KID:

*The system would have all of the KID functions.
*With up to 1kw PV,  3 large 60cell mods would fit perfectly in a 90volt single string.
*It could use the MNEDC breakers for the entire system. (GFCIs too.)
*Perfect fit for (4) L-16s or similar size battery but could also fit smaller AGMs etc...
*Perfect fit for a 2-3kW generator. (Very common size)
*Easily upgradable by adding a second KID.
*AC in and out on 20 amp circuits.

With the capabilities of the KID or the Classics, there is little need to make the inverter very complicated. You could keep it small.  If you wanted to keep it really simple, a few dip switches or an optional display (removed after programming) would be all you need, or even make it so the KID could be a full function controller... then add the dream of making a smartphone comm/control app via bluetooth or wifi....


This would be able to run anything you'd need for a cabin or small home and be emergency power for most domestic needs. It could run any Grundfos SQF pump, most pressure pumps, washers and dryers, almost any fridge...

For now I'll just have to match the KID with the MMS1012 or the ...oh nevermind.

Longing for more Midnite magic.

Alex A.

[zoneblue]

Also a fan of smaller inverters. You can do an awful lot with 1kW. Theres 1kW kettles on ebay, 1kW irons if you hunt around. Inverter fridges, washing machines run on 1kW, and so on.

Problem is the small inverters tend to punch a hefty price tag. For brand name in 24V sub 1kW try Victron, or Steca. Powermaster also make some.

Ditto on the dipswtiches. Inverters are dumb in my world too, dont need fancy display/controls. WbJr can tell you most of what you need to know about what the inverter is doing.

[boomadge]

2 or 3 cents here:

I'd like to see a small inverter sized with consideration of a whole system, including matching to a CC and a convenient PV array,  BOS equipment, available generators, common battery sizes... the whole works.

The KID CC  is an awesomely capable little whelp.  Matching it with a fairly "dumb" and little inverter charger can make a very nice little system.  The trouble is most of "dumb little" inverter chargers are 12 volt and just a touch too small for many applications. At 12 volts, the KID is limited to <500 Watts of PV.

Now, if you guys made a small (same physical size as the MMS) 24volt, 1800w, 120vac inverter/charger, match it with a KID:

*The system would have all of the KID functions.
*With up to 1kw PV,  3 large 60cell mods would fit perfectly in a 90volt single string.
*It could use the MNEDC breakers for the entire system. (GFCIs too.)
*Perfect fit for (4) L-16s or similar size battery but could also fit smaller AGMs etc...
*Perfect fit for a 2-3kW generator. (Very common size)
*Easily upgradable by adding a second KID.
*AC in and out on 20 amp circuits.

With the capabilities of the KID or the Classics, there is little need to make the inverter very complicated. You could keep it small.  If you wanted to keep it really simple, a few dip switches or an optional display (removed after programming) would be all you need, or even make it so the KID could be a full function controller... then add the dream of making a smartphone comm/control app via bluetooth or wifi....


This would be able to run anything you'd need for a cabin or small home and be emergency power for most domestic needs. It could run any Grundfos SQF pump, most pressure pumps, washers and dryers, almost any fridge...

For now I'll just have to match the KID with the MMS1012 or the ...oh nevermind.

Longing for more Midnite magic.

Alex A.

I have been looking for such a gem for the cabin, I don't need 2000W plus constant (nor would I use it)but would like more than 1500.. And 21v-30v +/- .4 not adjustable for 24V invertor's under 2000W is just ridiculous IMO.

[niel]

i've been debating whether to post again or not as i do need another inverter to replace my mms1012 and i'm still saving toward a new inverter. after 2 failures with faulting i don't consider these as available options and would like a good inverter, aka midnite magic. so without the midnite magic research gave me the outback gfx 1424 as a near similar inverter. 2 problems here as 1 this is not ul approved in the u s and 2 going to an approved inverter means going >$1600 with much higher wattages than necessary. i use the inverter as a backups as well as optionally for off grid in the 1kva area, but the sell back would be a nice option just as the 1424 and other outbacks can do. yes, i want to up the battery voltage as 12v gives a very limited time of operation with most wattage ratings seen on inverters. i don't know if you guys will come out with an inverter to suit, but in spite of the rhetoric of it's out there already, i contend that it really isn't out there as much as you believe or we wouldn't be asking for something from midnite. we respect the quality from midnite and recognizing that the outbacks' very existence is due to the gudgels. something of quality from the u s competing with others that may be out there is a plus for the end users. maybe we should have your feedback on what you want to present to the public besides something different as how different can an inverter be? make it quality, u s made, and competitively priced. start somewhere even if it is simple off grid inverters of various voltages and wattages and go from there afterward. i would prefer not having to save this much just to replace an mms1012. note here that i also would need to replace the door on my e panel to match the new inverter and the outback would need the extra electronics aka the mate for my agm battery settings adding more costs yet. is there an answer or do i need to still go with overkill?

[zoneblue]

Thanks for keeping this thread alive Neil. Rereading it i noticed this:

When we got tare losses down to 16 watts on the Trace 4000W SW inverter, the co-sine inverter became obsolete. You all are kinda sorta on the right track though talking about methods to achieve low idle.

So what happened after that? Modern inverter tare seems to be growing if anything. VFX3024E datasheet says ~20W, i clocked it the other day pulling nearer 26W. Schneider stuff pulling over 40W etc.