SMA VS AIMS

[Deleted member 1888]

I need 12k inverter for my build but so far I have been recommended 2 different brands.

SMA Sunny Island 6048 x2
AIMS 12000 Watt Pure Sine Inverter Charger

I have been looking into them but Im not finding the best info on them. The SMA site shows that they are grid tided but ppl on youtube say they can be off grid. Also the SMA youtube site shows that ill need there charge controller or ill need a shut but they don't say what shunt to use. Pulse there is a software update but I have no idea what it is for, and the manual only shows it can use lead batteries. They also cost more than the Aims and I have to get them off ebay with no return policy.

Aims 1 inverter can do 120 and 240, the SMA needs 2 to get 240. The Aims also seems to be a bit simpler to set up and use, I have not seen any special requirements for it. So I think I can use my shunt I already have and my charge controller with it. I can buy them from the Aims site directly or off ebay or amazon. So far Aims is looking like the better option.

If Im missing something please let me know.

 

[GXMnow]

12,000 watts is a lot of power. Have you done a power audit and know you truly need that much?
To put this into perspective, I would need to turn on everything in my house at once to pull 12,000 watts. That is 50 amps at 240 volts. The only way I go over that is also using my MIG welder and my air compressor kicks on, with the A/C running and the microwave and toaster as well.

Is this system going to be completely off grid? Will it have a generator?

The SMA can sync up and assist a weak generator or a shore power feed. The AIMS must supply all of the load power, or bypass to grid, it can't assist another power feed. The SMA is UL listed and will meet building codes, where the AIMS most likely would not pass an inspection in most cities.

What are you planning to use for solar? A Sol-Ark or Skybox is expensive, but they include the solar MPPT built right in. There is a 12,000 watt So-Ark, and 2 SkyBox units would be 10,000 watts. You could use two Schneider XW's as well. You can also gang up Victrons. But to make the best inverter choice, we would need more information about how the system will be used. For purely off grid, there are some cheaper units like AIMS that can work just fine. Is the power from this system going to be important, or mission critical? If a loss of power would be a danger, then I would spend more on a UL listed unit. If it is a lot of small loads, maybe using 2 smaller inverters makes more sense as well. If one inverter fails, you only lose half of the power.

 

[toms]

It’s pretty easy to exceed 12kw for a typical household system.
I use SMA equipment, coupled to LiFePO4 cells via a REC-BMS.
Very easy to setup and easy to expand.
The main advantage for me was that the grid-tie part of the system was readily available extremely cheaply second hand. (5kw PV including cabling and racking and a Sunnyboy 5.0 inverter all for $1500)

 

[Deleted member 1888]

Im now looking at the as well.
SCHNEIDER ELECTRIC CONEXT XW PRO 6848 INVERTER/CHARGER

I found several vids about AIMS inverter dying after 1-4 years, some just stop working and others blow up. SO AIMS is out of the picture for me, now its between the SMA and the Schneider

 

[Picasso]

Can get this minus the battery box, I have one I've been playing with but havnt loaded it down hard yet with pumps. http://www.pomcube.com/netzero-plus-specs.html I also love my SMA's.

 

[SolarQueen]

As @GMXnow said, please give us your use case so we can better help what the best solution is. Off grid, grid tied, generator? What are your loads that you need 12kW? Location would help a bit too.

 

[Hedges]

Shunts - I haven't used one yet. A number of sources, but here are a couple, 300A or 500A and "50 mV"

https://www.grainger.com/product/SIMPSON-ELECTRIC-Switchboard-Shunt-440G34

https://www.grainger.com/product/GRAINGER-APPROVED-Shunt-12G457

I think 300A is sufficient for up to 2 Sunny Island, or 500A for up to four.

Shunt is only needed by Sunny Island if you have DC loads or DC charge controllers. If your DC charge controller is Midnight Classic, shunt is optional; another option is a data interface so it communicates the charge current it provides.

 

[Hedges]

Probably several battery inverters to choose from. Some are strictly DC coupled, others like Skybox allow AC coupling the way Sunny Island does.

If your peak power consumption is only during the day (running A/C), that's where AC coupling with grid-tie inverters makes their power available in addition to what battery inverter produces. Good to have PV panels and grid-tie inverters large enough to run the loads and recharge battery, while battery inverter provides surge current to start motors (including your well pump) and for nighttime loads.

A battery state of charge signal (two different DoD settings can be used to control some of the four relays in a pair of Sunny Island) can be used so things like well pump only operate on a nearly full battery. Operate while the sun shines, and save battery for nighttime to power your shore-power pedestal when your RV is plugged in.

 

[Deleted member 1888]

As @GMXnow said, please give us your use case so we can better help what the best solution is. Off grid, grid tied, generator? What are your loads that you need 12kW? Location would help a bit too.

I am making a off grid permanent RV 50 amp plug and running a well pump, full size fridge and freezer. The RV has a 6.5kw gen in it so it will never need more than that to run everything in it. The fridge and freezer once up to temp never pull more than 400w together. The only thing that I don't know yet is the well pump, but I can simply use less power in the RV until the pump stops. If it turns out I need more power then ill add another inverter to the it to bump up the power. I read the owners manual of the RV and its only a 5.5kw RV hence why its need a 50 amp pluge as 30 amp can only provide 3.6kw.

 

[Hedges]

When your RV is parked there, beside RV plugging in to the PV/inverter/battery system on your land, you can also plug the inverter into your generator's RV. If battery gets low, inverter can request generator start and recharge batteries. That will let you get by with smaller, cheaper battery; it can be sized just for typical nighttime draw, and use generator if you get multiple heavily overcast days.

Because the generator has moving mass, it can deliver a high surge current to start multiple rooftop AC drawing more than 5.5 kW just momentarily. Inverters need to be able to put out the higher power based on their surge rating.

Plug is probably standard for RV hookups, although yours wouldn't draw max current. Or maybe all 50A drawn from one 120V leg? That's 6 kW. Probably split into two circuits, 25A each typical draw. The 50A plug could provide 120/240V 50A. Other RV plugs are 30A 120V.

 

[dmholmes]

The main advantage for me was that the grid-tie part of the system was readily available extremely cheaply second hand. (5kw PV including cabling and racking and a Sunnyboy 5.0 inverter all for $1500)

Where do you look for this second hand? And installation?

 

[Trukinbear]

The Sunny Island SI6048 can be grid-tied, or off-grid - AC or DC coupled, and their warranty is 10 years.
There are a lot of them on the market for less than half their list price due to a large solar installer going bankrupt a few years back. You can probably get two of them for $3400-$4100 or so. SMA is like the largest solar equipment supplier in the EU and Germany is almost totally electrified by SMA inverters. AIMS is junque IMHO. 2nd choice is a tie between Schneider (xantrex) and Outback in my book.

 

[SolarQueen]

Is your well pump 120V or 240V? There is absolutely no reason you need 12kW of inverter based on your list.

I'd suggest looking at the Magnum PAE4448 and Outback FXR3648. A couple of those would be more than enough, and able to handle 120/240 (a single Magnum can, Outback, you'd need 2).

 

[Deleted member 1888]

Is your well pump 120V or 240V? There is absolutely no reason you need 12kW of inverter based on your list.

I'd suggest looking at the Magnum PAE4448 and Outback FXR3648. A couple of those would be more than enough, and able to handle 120/240 (a single Magnum can, Outback, you'd need 2).

Most of the pumps im looking at are 120 or 240 I just don't know what the draw will be on them, they don't give that much info on power needs.

 

[ghostwriter66]

12kW -- holy cow .. you could run everything listed and a small town with that ... YOU need to do an energy audit ... no way you are running all of that at one time ... We run allot of 5K here and load them down and they push allot of electrons to allot of stuff ... we are just careful that everyone doesn't through the ON switch at the same time ...

 

[Hedges]

Most of the pumps im looking at are 120 or 240 I just don't know what the draw will be on them, they don't give that much info on power needs.

If any long distance, 240V is preferred for 1/4 the power loss in the wire, and less voltage drop for starting surge.
How deep is the water table? That drives a lot of things, like what kind of pump.

Other reason for 240V is if you use AC coupled grid-tie inverters, they are all 240V.
While DC coupling is also available, and most common for off-grid, a problem is you have to make sure peak current delivered isn't higher than what your batteries should get. Some DC charge controllers can handle this, I think, but not all.
With AC coupling you can get away with a very small battery and small charge current, but very big PV array, good for loads during the day.

 

[Deleted member 1888]

12kW -- holy cow .. you could run everything listed and a small town with that ... YOU need to do an energy audit ... no way you are running all of that at one time ... We run allot of 5K here and load them down and they push allot of electrons to allot of stuff ... we are just careful that everyone doesn't through the ON switch at the same time ...

I know I know everyone tells me that I just want to make a system that can pull it IF i needed it. Im going to start small and build up to it slowly, there is nothing wrong with having to much power. Im also going to keep adding lifepo to my system untill I run out of space. or lifepo sell out, or I run out of money.

 

[Hedges]

12kW -- holy cow .. you could run everything listed and a small town with that ... YOU need to do an energy audit ... no way you are running all of that at one time ... We run allot of 5K here and load them down and they push allot of electrons to allot of stuff ... we are just careful that everyone doesn't through the ON switch at the same time ...

No, his loads aren't that heavy. Started out as supplying 240V, 50A just like an RV shore power pedestal. The RV in this case is expected to draw half of that and has 6.5 kW generator. But Inverter should be heavy enough to start A/C, also a well pump (specs TBD)

 

[Deleted member 1888]

If any long distance, 240V is preferred for 1/4 the power loss in the wire, and less voltage drop for starting surge.
How deep is the water table? That drives a lot of things, like what kind of pump.

Other reason for 240V is if you use AC coupled grid-tie inverters, they are all 240V.
While DC coupling is also available, and most common for off-grid, a problem is you have to make sure peak current delivered isn't higher than what your batteries should get. Some DC charge controllers can handle this, I think, but not all.
With AC coupling you can get away with a very small battery and small charge current, but very big PV array, good for loads during the day.

I hate the idea of small battery banks I already have a 15kw bank and im going to keep adding to it. I have already had a week of bad weather that pushed my bank very low. So im going to build it up so that will not happen again.

 

[Hedges]

I like the idea of two Sunny Island (want more people to have a system like mine.) I think just one would start motors up to 2hp. Put in two, and if one fails later and can't be replaced because obsolete, a 120/240V transformer can be used instead and the surviving Sunny Island will still do everything.

Single Sunny Island would also do the job if all PV is DC coupled. But I like AC coupling.