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Sunsynk 5kW - Charge from PV by day and discharge from batteries by night


Ant Seiderer

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My requirements are as follows:

08:00 - 17:00 Charge from PV only. Excess PV to supply load.

17:00 - 18:00 Charge from grid if SOC < 100%

18:00 - 08:00 Discharge batteries down to, say, SOC = 50%, then supply load from grid.

I'm struggling to understand what System Mode timer settings to use. Also, my System Mode timer has data in all the rows. How do I delete data from unrequired rows?

In Battery Setup, under the Batt Charge tab, presumably Grid Charge should be ticked? I'm confused about this, as the grid should indeed charge at the end of the day if required, but for the bulk of the day PV should do the charging.

 

Any help would be appreciated.

 

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54 minutes ago, Ant Seiderer said:

My requirements are as follows:

08:00 - 17:00 Charge from PV only. Excess PV to supply load.

17:00 - 18:00 Charge from grid if SOC < 100%

18:00 - 08:00 Discharge batteries down to, say, SOC = 50%, then supply load from grid.

I'm struggling to understand what System Mode timer settings to use. Also, my System Mode timer has data in all the rows. How do I delete data from unrequired rows?

In Battery Setup, under the Batt Charge tab, presumably Grid Charge should be ticked? I'm confused about this, as the grid should indeed charge at the end of the day if required, but for the bulk of the day PV should do the charging.

 

Any help would be appreciated.

 

Need some more info-- is it a 3K, 5K or 8K model? Are you feeding into the grid? Do you have non-essential loads before the inverter that you want to power?

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Apologies for the lack of information.

I have a 5kW 1P inverter exporting to the grid and I have non-essential loads to be powered before the inverter.

I have a CoCT bi- directional meter.

As I want to export to the grid once the batteries are fully charged and the load is satisfied, I have ticked "Solar Export".

Also, as I want to prioritise battery charging first, I have "Priority Load" unticked.

 

I will try your suggestion. I note that you have inserted dummy (repeated) entries to "pad out" the number of lines. Is there no way to delete unwanted lines?

What is the thinking behind limiting the PV-supplied charge to SOC = 80%? If this can't be 100%, could it be, say, 98%?

 

Thanks for your help.

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7 minutes ago, Ant Seiderer said:

Apologies for the lack of information.

I have a 5kW 1P inverter exporting to the grid and I have non-essential loads to be powered before the inverter.

I have a CoCT bi- directional meter.

As I want to export to the grid once the batteries are fully charged and the load is satisfied, I have ticked "Solar Export".

Also, as I want to prioritise battery charging first, I have "Priority Load" unticked.

 

I will try your suggestion. I note that you have inserted dummy (repeated) entries to "pad out" the number of lines. Is there no way to delete unwanted lines?

What is the thinking behind limiting the PV-supplied charge to SOC = 80%? If this can't be 100%, could it be, say, 98%?

 

Thanks for your help.

1. You need to insert dummy lines as you can't delete or have blank lines.

2. It's the SOC at which point it will stop using batteries. The timer has 2 functions. It's the SOC at which point the batteries will stop being used so if its set to 80%, batteries will only be used during that time until the SOC is reached. If grid charge or gen charge is ticked, it becomes the target point for grid or gen charge to stop if you have it ticked and set at 100% it will start charging from grid at that time and stop at the set SOC. 

Edited by Achmat
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1 minute ago, Ant Seiderer said:

Apologies for the lack of information.

I have a 5kW 1P inverter exporting to the grid and I have non-essential loads to be powered before the inverter.

I have a CoCT bi- directional meter.

As I want to export to the grid once the batteries are fully charged and the load is satisfied, I have ticked "Solar Export".

Also, as I want to prioritise battery charging first, I have "Priority Load" unticked.

 

I will try your suggestion. I note that you have inserted dummy (repeated) entries to "pad out" the number of lines. Is there no way to delete unwanted lines?

What is the thinking behind limiting the PV-supplied charge to SOC = 80%? If this can't be 100%, could it be, say, 98%?

 

Thanks for your help.

Great, then you have it!

The dummy entries become useful when you need to change things.  It's also important that the entries start at around midnight, have heard of issues when your first entry is say 21H00. So I'd also rather not delete unwanted lines, could have a strange effect. I have found that "padding" with dummy entries is best, not sure if someone else has a better solution.

SOC=80% could be 100%, but then it will not use battery at all during the day, so if you have a bad solar day / week with lots of clouds, you will draw from grid rather than battery. I don't want to draw anything from grid (my Eskom bill usage was under 5kWh last month).

 

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49 minutes ago, Ant Seiderer said:

The bi-directional meter cost me nearly R12k. Big mistake!

Oh wow! Then again, that's water under the bridge (sorry to say).  

How is it treating you, is a more appropriate question at this point. Could you please publish your figures? Regularly? At the least, it would definitely help others who may be contemplating the same, whether good or bad. It may even attract the attention of some COCT people, who may eventually realise that they are cutting off their nose to spite their face... 

 

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2 hours ago, Ant Seiderer said:

The bi-directional meter cost me nearly R12k. Big mistake!

Ouch 

Why do you then want to charge from the grid? I manually set the grid charge but only if its above stage 4 load shedding and solar did not manage to charge the batteries in time. 

The more you use from the grid, the longer it will take you to recover your costs. Just set your max discharge to 40% but its really a waste to charge from the grid unless its an emergency and you not going to have enough battery when load shedding hits you. I only did this once this year. 

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35 minutes ago, Achmat said:

Ouch 

Why do you then want to charge from the grid? I manually set the grid charge but only if its above stage 4 load shedding and solar did not manage to charge the batteries in time. 

The more you use from the grid, the longer it will take you to recover your costs. Just set your max discharge to 40% but its really a waste to charge from the grid unless its an emergency and you not going to have enough battery when load shedding hits you. I only did this once this year. 

Agreed. The only (and last) time that I charged batteries from the grid was late August last year 😄 The batteries were newly installed at the time by my trusty installer, and no-one understood how to set it up. I only realised it a few months later when I was browsing through my data 🤣

Edited by YellowTapemeasure
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6 hours ago, YellowTapemeasure said:

If you don't want to draw anything, and you have a 5K inverter, then try this:

 

 

System mode screen3.png

Thanks so much!

 

I've entered conservative settings based on your recommendation, and all is well so far.

6 hours ago, Achmat said:

You need to insert dummy lines as you can't delete or have blank lines

All understood and easy to comply with - thank you

 

4 hours ago, YellowTapemeasure said:

Could you please publish your figures? Regularly?

I'd be happy to. Can you suggest what data would be helpful, in what format, and how best to publish it?

I take that R12k as penance for the prior 8 years I exported on a rotating disc meter, thus enjoying a feed-in tariff equal to my purchase price.

3 hours ago, Achmat said:

Why do you then want to charge from the grid?

I only want to charge from the grid after a bad solar day that hasn't managed to fully charge the battery (to be prepared for a night of possible loadshedding). I could also do this manually when I see a bad situation coming.

 

I currently only have  1 x Hubble AM2 battery and a 2.88kW solar array, so I'm really just experimenting with charge settings and scenarios until I upgrade to double my battery and PV capacity. Everybody's help has been invaluable - thank you all.

 

 

 

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49 minutes ago, Ant Seiderer said:

Thanks so much!

 

I've entered conservative settings based on your recommendation, and all is well so far.

All understood and easy to comply with - thank you

 

I'd be happy to. Can you suggest what data would be helpful, in what format, and how best to publish it?

I take that R12k as penance for the prior 8 years I exported on a rotating disc meter, thus enjoying a feed-in tariff equal to my purchase price.

I only want to charge from the grid after a bad solar day that hasn't managed to fully charge the battery (to be prepared for a night of possible loadshedding). I could also do this manually when I see a bad situation coming.

 

I currently only have  1 x Hubble AM2 battery and a 2.88kW solar array, so I'm really just experimenting with charge settings and scenarios until I upgrade to double my battery and PV capacity. Everybody's help has been invaluable - thank you all.

 

 

 

Ok. So looking at your battery and solar array size then it does make sense to utilise the grid charge on bad solar days. 

Hopefully the savings will add up quickly so you can add more panels. Max your panels first before adding more batteries. Savings will come from generating your own electricity. 

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Agree with Achmat on adding panels, I have 4.8 kWh of batteries, have a 4.2 kWp solar array currently, adding panels for a total of 6.4 kWp array, so in winter I can cover all loads including geyser and in summer be able to run aircons and pool pump as well for most of the day.

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If I may jump into this thread...
I have a similar need to setup my new Sunsynk 5kW 1P that has just been installed...
I have PV and Pylontech batteries and the inverter is connected to the grid feed.

I would like the batteries to be charged from PV every day until they are 100% then the PV should feed the inverter load and if still excess PV then feed it to the house (CT coil installed and working).
The batteries also need to be charged from the grid but only up to 50% SOC, just to ensure enough battery to get through another load shed should it happen (or just a general power failure). (I think I've currently got this set to only charge from grid from 18:00 to 08:00 which is fine if it's correct)
The batteries should never be used to supplement the house load, only ever the inverter load (UPS is looks to be referred to on the flow chart display).
Then from 18:00 until 08:00 the batteries need to supply the inverter load, until they reach 50% SOC, to allow for a possible load shed during the night.

After reading this thread, and a few others around, I've come up with the following that I have set this afternoon only so don't know yet whether it's correct.
Please could those in the know check this and let me know if I'm correct or not and if not what I need to change. (the last two lines are just fillers but may need changing)


367218606_SSSystemMode-settings01.png.79e38fb4ce68b84225862889209ed442.png

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Ok firstly some more info needed, what size battery do you have? Do you have a prepaid power meter ? you need to delete the solar export tick(this is used when you sell back to grid) and tick limit to load only for starters (so the battery wont get used on non essentials).   Also when you do this you lose out on supplementing your non essentials with solar/battery during the day which is one of the major features of the inverter.  Edit where you have 100% for 8 in the morning make that 50% aswell , then dont tick limit to load, with the rest like it is. The you will use battery up until 50% , when sun comes up battery will charge up past 50% to 100(assuming there is enough solar) and then supplement that to all your loads . (this had me confused at the beginning) If you set the battery to 100% soc through the day it wont supplement your loads with the battery .

Edited by Nexuss
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Hi Nexuss
Thank you for the reply.
Batteries: I have two Pylontech US3000's, connected via the CAN port to the Sunsynk.
I do have a pre-paid meter.

My understanding with the "Solar Export" was that if that is ticked then the excess PV (after charging the batteries) will be pushed to the grid, but limited to the "Zero Export Power" value to always be pulling from the grid, hence the requirement for the working CT coil. This part seemed to be working today as I was seeing the House watts value fluctuating during the day but the Grid watts was only lower than the 100w setting when the house was pulling less from the grid, then the inverter seemed to throttle the PV so as to not push to the house when it shouldn't be.

If "Limit to Load Only" will prevent the excess PV from feeding to the House then I'd rather let the batteries just feed that in the evening, down to only 50% SOC though, as at the end of the day I guess it's 6 of one or half a dozen of the other whether the battery supplies the House (non-essential load) as well as the inverter load and then switches back to using grid for all just earlier than if it was just supplying the inverter load...

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How big is your PV array? I have only one Us3000 for now and 4,5kw of pv. I never use grid charge . I set battery soc to 90 % through night from 5pm to 5 am , then it runs down to 50% at 7am and then down to 30% at 10 am . then i have a 60% soc for 2pm  .  I use about 40% of the battery in loadshedding. 

Edited by Nexuss
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51 minutes ago, RhysMcW said:

If I may jump into this thread...
I have a similar need to setup my new Sunsynk 5kW 1P that has just been installed...
I have PV and Pylontech batteries and the inverter is connected to the grid feed.

I would like the batteries to be charged from PV every day until they are 100% then the PV should feed the inverter load and if still excess PV then feed it to the house (CT coil installed and working).
The batteries also need to be charged from the grid but only up to 50% SOC, just to ensure enough battery to get through another load shed should it happen (or just a general power failure). (I think I've currently got this set to only charge from grid from 18:00 to 08:00 which is fine if it's correct)
The batteries should never be used to supplement the house load, only ever the inverter load (UPS is looks to be referred to on the flow chart display).
Then from 18:00 until 08:00 the batteries need to supply the inverter load, until they reach 50% SOC, to allow for a possible load shed during the night.

After reading this thread, and a few others around, I've come up with the following that I have set this afternoon only so don't know yet whether it's correct.
Please could those in the know check this and let me know if I'm correct or not and if not what I need to change. (the last two lines are just fillers but may need changing)


367218606_SSSystemMode-settings01.png.79e38fb4ce68b84225862889209ed442.png

OK so firstly you have committed The Cardinal Sin 😄: Never start the first entry at 18H00, always use the time entry closest to 00H00, and then the next chronological time in time slot 2. It also makes the flow more logical and easier to understand.

I also think that if you use dummy entries, then they should be the exact same entry as the previous one, just at a later time. 

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52 minutes ago, Nexuss said:

How big is your PV array?

I have two arrays both 2kW, one east and one west facing (roof availability).
I have some of the load, form the inverter load, setup with contactors that are off when Eskom is off so that I can keep more battery power for the important things in the house, like lights, TV and our offices.
With my old Infini inverter the batteries would last until around 22:00 (now in winter) when they reached 50%.

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40 minutes ago, YellowTapemeasure said:

OK so firstly you have committed The Cardinal Sin 😄: Never start the first entry at 18H00, always use the time entry closest to 00H00, and then the next chronological time in time slot 2. It also makes the flow more logical and easier to understand.

I also think that if you use dummy entries, then they should be the exact same entry as the previous one, just at a later time. 

thanks @YellowTapemeasure, will go adjust the settings accordingly😊

Of course that whole setup would've been easier, and logical, if it had a start and end time per line...

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2 minutes ago, RhysMcW said:

thanks @YellowTapemeasure, will go adjust the settings accordingly😊

Of course that whole setup would've been easier, and logical, if it had a start and end time per line...

Maybe, but then the inverter may struggle with what it needs to do if one timer ended before another one started. This way it's idiot proof.

You are just going through the same learning curve that we all did with Sunsynk, the first 3-5 days are a little confusing, but soon you will get the hang of it.

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19 minutes ago, RhysMcW said:

I have two arrays both 2kW, one east and one west facing (roof availability).
I have some of the load, form the inverter load, setup with contactors that are off when Eskom is off so that I can keep more battery power for the important things in the house, like lights, TV and our offices.
With my old Infini inverter the batteries would last until around 22:00 (now in winter) when they reached 50%.

Ok cool thats exactly about what i have in regards to PV and directions on roof.  that second sentence is interesting , why would you not just put those loads on the non essential side ? or am n missing something ? i dont think you quite fully understand how this inverter works yet , you will soon though it takes a while haha. took me a few months to realize some of my settings were causing me to not save as much on power as i could have .

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23 minutes ago, Nexuss said:

Ok cool thats exactly about what i have in regards to PV and directions on roof.  that second sentence is interesting , why would you not just put those loads on the non essential side ? or am n missing something ? i dont think you quite fully understand how this inverter works yet , you will soon though it takes a while haha. took me a few months to realize some of my settings were causing me to not save as much on power as i could have .

I previously had an Infinisolar that could not do what the Sunsynk does with feeding to the house but not the grid, by using the CT coil, so to use more of the PV during the day, but not drain the batteries if no grid, I put things like my pond pumps and fridge via the contactors driven by Eskom power...
I guess all that is no longer needed but seeing as it's in place I'll probably just leave it as is.

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