Sol-ark - eating their own dog food?

[Think About It]

I have Solar Assistant attached also but I use Power view to change my settings. While I could use Solar Assistant to make changes I find Power view easier. Solar Assistant just shows the information better for you. If you want the gen to auto start and charge you will need to check gen charge for all time periods and set it lower than your grid charge settings. I think once you familiarize yourself with it you will find it much easier to set a grid charge period get your batteries at 100% then work off your batteries. Otherwise you will be endlessly checking on your system to get what you want. If you let the Sol Ark do its thing you almost never have to mess with it unless something happens out of the ordinary. I check mine once a day usually to set up which 2 hrs of the day I will charge. I find we work well in the 40-100% SOC range but can go much lower if we have a grid outage. I also grid sell our excess. I have never used load priority but from your post I think I can do everything you are asking for. On my attachments yesterday we had power for $2.5 cents per kWH from 2300-0400. I elected to charge my batteries and stay on grid for those hours. These are the settings I used to do that. At 0400 we went back on battery and off grid. I figured with cheap power might as well use it.

I'm curious why you are using "Limited to home". I've gotten conflicting information about this from Sol-Ark. The more experienced techs have stated that I should be "Limited to Load" for my use case. They explained that I only would use "Limited to Home" if my Sol-Ark was wired as a sub-panel off my main load center.

 

[robby]

Yes I agree with your assessment. I'm on closed loop. I have also been on Voltage and percent. The problem with percent is that the inverter has to continually "relearn" the SOC.

Tomorrow I'm going to try a few things. First, a complete reboot - which I hate to do. I'm tired of setting the oven and microwave clocks. LOL Even though I have a transfer switch to take the Sol-Ark out of the loop, my mains are tapped and to cut grid I have to kill power entirely to the home.

The second thing is that I'm going to change my SOC to 20% in my TOU. My theory is that the SOK batteries may be reporting that they are at cutoff at 17% causing the Sol-Ark to charge them. What doesn't make sense is that I have "Grid charge" disabled, so the grid should never charge the batteries.

Percentage mode sucks. It drifts a lot unless you get up to 100% SOC at least every 2-3 days
If it is in closed loop the Inverter is not learning the SOC, it is taking the batteries reported SOC and averaging out the SOC for all the batteries connected. I highly suggest you look at all of the LCD screens and see if the Average SOC is adding up to what the Sol-Ark is reporting. It is very easy for one battery in the string not to be communicating with the Sol-Ark due to a bad cable or dip switch setting.

The second issue is that the BMS suffers from the same problem as the Sol-Ark just in a slower way.
If the BMS does not get a full charge every week or so it will start to drift and the accuracy will go off.
YMMV depending on the quality of the Batteries and BMS.

The third issue is that you cannot use SOC with so much precision!
The head engineer of Fortress Power told me this after I tried some 5% Increments in my settings. He said that he recommends no less than 10% increments if you want to make sure there are no long term issues with TOU or other settings that are using SOC.

 

[Think About It]

It is very easy for one battery in the string not to be communicating with the Sol-Ark due to a bad cable or dip switch setting.

Is there a way to see if the Sol-Ark is communicating with all of the batteries on the CANbus? or does it treat the array of batteries as one battery?

 

[Llaves]

Is there a way to see if the Sol-Ark is communicating with all of the batteries on the CANbus? or does it treat the array of batteries as one battery?

I suspect that it may depend on whether the batteries communicate with each other using the CANbus protocol or some other.

For my batteries (MeritSun), the batteries communicate with each other over an RS-485 connection, and the Sol-Ark sees the four batteries as a single unit through the CANbus connection. The BMS reports the average SoC of the four batteries. It's supposed to report the sum of the charging capacity but it's not doing that, which rules out the closed-loop control in my case. My battery vendor supplies software for monitoring the batteries so I'm able to verify that each battery is communicating with the one that is connected to the inverter.

On the other hand, I reach 100% SoC most days, so the drift isn't a real issue.

 

[629658]

I'm curious why you are using "Limited to home". I've gotten conflicting information about this from Sol-Ark. The more experienced techs have stated that I should be "Limited to Load" for my use case. They explained that I only would use "Limited to Home" if my Sol-Ark was wired as a sub-panel off my main load center.

When I went through the manual Limited to home offer more options than limited to load and it better fit my needs. I do have an interconnect agreement so we do grid sell our excess. After reading through it again my settings may not apply to limited to load. I read it to say limited to load reduces inverter output to match the loads so that is limiting your PV production to only what you need. No excess will be grid or home sold. So that means your PV production is being throttled back to make your loads only. I am wired to my load center and not a sub panel. Works great and when I said I am doing what you want I am.

 

[Think About It]

When I went through the manual Limited to home offer more options than limited to load and it better fit my needs. I do have an interconnect agreement so we do grid sell our excess. After reading through it again my settings may not apply to limited to load. I read it to say limited to load reduces inverter output to match the loads so that is limiting your PV production to only what you need. No excess will be grid or home sold. So that means your PV production is being throttled back to make your loads only. I am wired to my load center and not a sub panel. Works great and when I said I am doing what you want I am.

Regarding "Limited to Load". I question "This mode will neither sell back to the Home or Grid." I take that to mean "sell back" out of the "Grid" connection on the Sol-Ark. Does home refer to the Grid connection, the Load connection or both? It's ambiguous.

I believe that "Limited to Home" is used when your Sol-Ark Grid terminals are wired as a sub-panel to your main load center. You would then put CTs ahead of your main load center. The Sol-Ark will then push power back to the load center but only enough so that your main load center will not push power back to the meter. Hence "Zero-Metering"

 

[cm119]

I believe that "Limited to Home" is used when your Sol-Ark Grid terminals are wired as a sub-panel to your main load center. You would then put CTs ahead of your main load center. The Sol-Ark will then push power back to the load center but only enough so that your main load center will not push power back to the meter. Hence "Zero-Metering"

That sounds right, but do you have the CTs installed and have you tried it? I wonder if Limited to Home will help the behavior you are seeing with PV not supplying your full load. I think most installs I have researched are using Limited to Home, including those with 15Ks running the whole panel. Maybe just different logic, or the system behaves better with the CTs than without.

 

[629658]

Regarding "Limited to Load". I question "This mode will neither sell back to the Home or Grid." I take that to mean "sell back" out of the "Grid" connection on the Sol-Ark. Does home refer to the Grid connection, the Load connection or both? It's ambiguous.

I believe that "Limited to Home" is used when your Sol-Ark Grid terminals are wired as a sub-panel to your main load center. You would then put CTs ahead of your main load center. The Sol-Ark will then push power back to the load center but only enough so that your main load center will not push power back to the meter. Hence "Zero-Metering"

I’m not sure on the home sell but I think that means it will not push more power than the loads require just as grid sell is pushing excess to the grid and gen sell is pushing excess to the gen (bad).

Unless you select grid sell then excess is sold back to the grid.

 

[629658]

That sounds right, but do you have the CTs installed and have you tried it? I wonder if Limited to Home will help the behavior you are seeing with PV not supplying your full load. I think most installs I have researched are using Limited to Home, including those with 15Ks running the whole panel. Maybe just different logic, or the system behaves better with the CTs than without.

Yes proper CT placement is necessary

 

[Think About It]

That sounds right, but do you have the CTs installed and have you tried it? I wonder if Limited to Home will help the behavior you are seeing with PV not supplying your full load. I think most installs I have researched are using Limited to Home, including those with 15Ks running the whole panel. Maybe just different logic, or the system behaves better with the CTs than without.

I have the CTs installed but I've been told that they're not necessary when the solar is in line with grid and load center.

I'm not sure whether the CTs are used or not when using "limited to load" mode. I have also never seen any official documents saying that the external CTs are more accurate than the internal CTs.

 

[629658]

I have the CTs installed but I've been told that they're not necessary when the solar is in line with grid and load center.

I'm not sure whether the CTs are used or not when using "limited to load" mode. I have also never seen any official documents saying that the external CTs are more accurate than the internal CTs.

In limited to load they may not be necessary in limited to home they definitely are required

 

[robby]

In limited to load they may not be necessary in limited to home they definitely are required

As far as I know they are needed in both modes.

 

[Think About It]

As far as I know they are needed in both modes.

They are only required in limited to home.

C.T. Sensor FAQ’s - Sol-Ark -

Sol-Ark - - Sol-Ark - C.T. Sensor FAQ’s - https://www.sol-ark.com/c-t-sensor-faqs/ - News - Thomas - M - January 20, 2023 - 20 - January

www.sol-ark.com

 

[Ampster]

As far as I know they are needed in both modes.

I have the external CTs installed, but not hooked up yet and I am using Limited to Load mode.

 

[Think About It]

I just raised my SOC in my TOU from 15 to 20% and charged the batteries to 20%. I'll see if there's any difference in problem #3 in the morning. Somebody here got me thinking that the BMU may be causing the issue. I'll find out soon enough when the sun comes up.

 

[Spunky]

Regarding "Limited to Load". I question "This mode will neither sell back to the Home or Grid." I take that to mean "sell back" out of the "Grid" connection on the Sol-Ark. Does home refer to the Grid connection, the Load connection or both? It's ambiguous.

I believe that "Limited to Home" is used when your Sol-Ark Grid terminals are wired as a sub-panel to your main load center. You would then put CTs ahead of your main load center. The Sol-Ark will then push power back to the load center but only enough so that your main load center will not push power back to the meter. Hence "Zero-Metering"

A picture is worth a thousand words... (a video is 1K pictures)

I have the 15K with 7.2.2.2, off grid (but grid is there at a flip of a switch) and use the grid input with my 7000w gen using grid-shaving at 5500w.

My whole house is connected to the Load terminals (this places my Home after the inverter) as the 15K can handle my down sized home.
In the below picture, the HOME is connected between the inverter and the grid. The inverter could send enough power to the HOME, but Limit it, so as not to push through the CTs back to the grid.

I've found things that didn't make sense to me too, but after learning how others are using all the feature, it's really neat.

 

[Llaves]

I am wired to my load center and not a sub panel. Works great and when I said I am doing what you want I am.

I think in your case (ie, no sub-panel), limited to home and limited to load are the same. If you have the inverter feeding a subpanel, then limited to load means just the load on the subpanel, while limited to home uses the CTs to measure the loads on the main panel and feeds that too. (Or at least that what it sounded like after some back and forth with tech support.)

 

[Spunky]

I think in your case (ie, no sub-panel).....

Right, it's just when it says, "Home" that isn't necessarily where everybody's house is. And the same with the Gen Port, it's meaning changes depending on what is attached and configured.

If the Grid Port was labeled "Grid/Home", the setting may be easier to grasp initially or find a better description than 'Home'. It totally makes sense, if your system looks like the picture.

I hear Sol-Ark is working on a new App, hopefully it will have explanations for the different setting.

 

[Think About It]

Right, it's just when it says, "Home" that isn't necessarily where everybody's house is. And the same with the Gen Port, it's meaning changes depending on what is attached and configured.

That is exactly what I was inferring to. The definitions of limited to home and limited to load should be using the name of the port. There is also the case where people have the output of the Sol-Ark tied to a breaker in their load center, no grid, no generator. So in this case the Home is on the Load port. In the other cases the Home could be on the Grid port.

 

[Think About It]

Problem #3) is looking better this morning. I think what was happening is the battery via the canbus was somehow telling the inverter to charge it. I believe the sok battery is signaling the inverter to do something at 17% SOC. My TOU setting was previously at 15% SOC and I raised it last night to 20% SOC.

 

[Ampster]

The definitions of limited to home and limited to load should be using the name of the port.

The way I understand it is, Limited to Load implies the load port. However, Limited to Home implies an external CT and presumably includes the Grid port. I think that is what you are saying as well.

 

[Think About It]

The way I understand it is, Limited to Load implies the load port. However, Limited to Home implies an external CT and presumably includes the Grid port. I think that is what you are saying as well.

?

 

[robby]

Problem #3) is looking better this morning. I think what was happening is the battery via the canbus was somehow telling the inverter to charge it. I believe the sok battery is signaling the inverter to do something at 17% SOC. My TOU setting was previously at 15% SOC and I raised it last night to 20% SOC.

Well I am glad we got problem #3 solved.

 

[Think About It]

Well I am glad we got problem #3 solved.

Well let's not celebrate yet. It's only one day. The battery should not charge from the grid regardless of what's going on. One could argue that the battery is charging from the PV, and that the grid is supplementing the load. In either case it should not happen because working mode is "load first" and grid charge is "off".

Dexter at Current Connected tech support did mention to me that I could safely draw the SOK batteries down to 5% but in order to do that I would have to use voltage mode. I would like to safely draw my batteries down below 20% in order to get the most power storage/usage out of them, thereby using less grid power.

Problem #4 worked correctly today. I suspect it's also related to the battery SOC change to 20%.

 

[robby]

Well let's not celebrate yet. It's only one day. The battery should not charge from the grid regardless of what's going on. One could argue that the battery is charging from the PV, and that the grid is supplementing the load. In either case it should not happen because working mode is "load first" and grid charge is "off".

Dexter at Current Connected tech support did mention to me that I could safely draw the SOK batteries down to 5% but in order to do that I would have to use voltage mode. I would like to safely draw my batteries down below 20% in order to get the most power storage/usage out of them, thereby using less grid power.

Problem #4 worked correctly today. I suspect it's also related to the battery SOC change to 20%.

No your problem is solved! Grid Charge has nothing to do with this.
If you want a smooth transition without using any Grid power you have to have enough batteries and take the time to calculate out your usage until you get to the point where your TOU settings are tweaked enough that the PV takes over the Load just before the Battery reaches the lowest level that you want it to.

This is how my system transitions in the morning. No Grid power is used and my cutoff SOC is 20% so I had 4% extra but on many mornings I will be at 22%-20% or I might be drawing a couple of hundred watts from the Grid. It all depends on what is being run at night.


I disagree with Dexter about going down to 5%. I know Will P. use to say go down to 0% in his videos and I disagree with him also. Follow the advice you think makes sense for you.
Most Teir1 companies will tell you not to go below 20% SOC if you want the most cycles out of the Batteries.