wolfandy

Ive gone back and did the number properly - my previous estimates were optimistic to say the least
System installed December 2021
Solar generation since then - 25.9MWh
Solar generation savings - R72k (using Tshwane block charges)
Grid used - 11.5MWh
Grid cost - R29k
Battery discharge - 11.7MWh
System cost me 185k all in done in 3 tranches (battery and panel upgrades) of 90, 45 and 50k. So I will have "saved" 50% of my system cost by the end of this year.

I surely can't be the only one here that has broken the 1 Megawatt-Hour for the month 😜

I have a single pole breaker like this.
Installed after the main incoming breaker and before the inverter feed.

Heh. When I started the Pylontech recommended voltages table, ICC was the dominant monitoring software. I guess that was a while ago now. I suspect that ICC worked a little differently than Solar Assistant does now.
I also have to come clean that I don't use a Pylontech or any other battery with a factory built-in BMS. My battery has a BMS, but it's a custom one totally different to any factory BMS.
It's also been a long time since I roughly knew how the BMS control via RS-485 or CAN bus works.
I note that your battery type above is Pylontech BMS. That means that the Pylontech BMS is calling the shots. Was the battery type that way when the damage occurred? It's really unfortunate that the BMSs all seem to work with very high voltages, and seem to assume superhuman control systems that Voltronic inverters in particular can't live up to.
When the inverter's battery type is Pylontech or one of the other several BMS types, settings like the bulk/absorb/CV battery voltage and float voltage are completely ignored. My table, as I noted in that post, is for people who aren't using the battery BMS connected to the inverter via the RS-485 or CAN bus cable. Are you connecting the BMS to the inverter directly, or to Solar Assistant? If the latter, I'm afraid that I don't know how it really works. It may be that SA tells the inverter that the battery type is USER, and manages the battery using messages from the battery BMS as a guide.
The inverters themselves have two battery charge current settings: maximum total charge current, and maximum utility charge current. I think that the idea is that you decide the total charge current based on the battery manufacturer's recommended maximum charge current, but the maximum utility charge current can be lower than that, in case you don't want to spend too much money on utility charges, or the generator has a limit, etc. I note that maximum total charge current is one of the settings that gets taken over by the BMS: "If selected, programs of 02, 26, 27 and 29 will be automatically set up. No need for further setting." Setting 02 is the maximum total charge current, 26 and 27 are the bulk/absorb/CV and float battery volage settings respectively, and 29 is the low DC cut-off voltage.
That's resumable because as above, the BMS takes over these settings.
What is setting 05 on the inverter itself? Presumably either PYL or USE.
Sorry I can't be more help.
 

If the inverters use parallel communication cabling, they must typically be connected to the same battery bank(Dc bus). Otherwise, the system will produce an error. The only way it could work if you split the loads between the 2 inverters so they function independently.
 

+1
When running inverters in parallel, both inverters should be connected to the batteries via a common bus bar. I don't think it is possible to run a parallel system with each inverter having it's own battery.
Also don't know if it is possible to run different batteries together in a system. I'd expect that you would run into all sorts of problems - as you are now experiencing.
I would say that you have 2 options:
Sell one battery and replace it with the same brand as they one that you are keeping Run each inverter separately (not in parallel), which would mean splitting your DB board across the 2 inverters I would recommend option 1

While it is technically possible to combine some models of batteries with the others, there's a lot of caveats and limitations.
Some of them being:
Voltage Cell count Chemistry BMS communication Warranty Based on that I can't recommend doing so. 
Upgrade as per manufacturers guidance, or sell what you have and rebuy from scratch.
 

Hi @jamila
To be honest, 6 panels for a family of five is almost nothing. 
Assuming cca 500Wp per panel, that would be just 3kWp, which translates to roughly 15kWh per day in SA. Not so bad on a first sight, but there's a lot of gotchas:
If the system is connected to the grid, and you start any load higher than 2,5kW and it's not perfect noon, then you will be drawing that missing power from the grid (or batteries.) On a cloudy/rainy day the power drops quickly. Next day, you have to satisfy the loads, but to charge the flat battery at the same time. If your house wiring is 3-phase, but the PV system is 1-phase, then the benefit is minimal. Etc. If you are not electrician, installer or PV geek, then I would advise you to get in touch with a reputable PV installer (or company) in your area, have them check your current PV system, loads, house wiring, family needs and then design a detailed plan of PV system upgrade based on the calculations.
If you want a quick answer, then from my experience the reasonable solar for a family house starts at 10kWp of PV (cca 20 panels), 20kWh of lithium battery, 10kW of inverter power. For offgrid use, 1-phase wiring and inverter makes sense most of the time. But like I said - check your situation with an installer.
 
Not to mention that I've seen 1-phase solar in a 3-phase house.
Or a PV system, that was configured as backup only, not helping the house loads at all.

+1
When running inverters in parallel, both inverters should be connected to the batteries via a common bus bar. I don't think it is possible to run a parallel system with each inverter having it's own battery.
Also don't know if it is possible to run different batteries together in a system. I'd expect that you would run into all sorts of problems - as you are now experiencing.
I would say that you have 2 options:
Sell one battery and replace it with the same brand as they one that you are keeping Run each inverter separately (not in parallel), which would mean splitting your DB board across the 2 inverters I would recommend option 1

I think you mean you have more than you need most days. I have enough most days, but on overcast days I struggle. I'm thinking that when I have the dosh, I'm either going to put up more panels, or replace the existing north facing panels with something that has a bit more oomph. 
OK... So how much energy on average do you consume in a day? Before I got solar this house was using 13 to 14 kWh a day (I knew this because I was on prepaid and so had to feed the meter, which made me aware of what I was buying).
I have as much battery as you less panels, smaller inverter. But I usually have 50% (ish) at 7:00 and that's after the heat pump has run to heat the geyser.
We are just two, as I read it so are you. So you can get through the night on that battery and actually do. But I have more in hand in case of morning load shedding. 
The aim you state is the right one. Maximise your use of solar. We run all our appliances during the day, heat water during the day. So we reduce the work the batteries have to do at night. 
Some possible advantages we have are full gas cooking, and a heat pump to heat our geyser. The pump is more efficient than a regular element. All our lighting is LED. 
Check how much electricity you use in a day, and then try to get an idea of time of day you use it. Data from the Deye will help here. 
Think about how much night time use you can shift to the day. 
You don't say where you live. I'm assuming South Africa, which is why I mentioned load shedding. If you live somewhere with a reliable supply it can still be worth your while to reduce battery usage at night. You'll have more in hand on overcast mornings. And your battery isn't working as hard which may extend it's life. 
I live in Johannesburg. I can't see a way I could as much as break even by reselling, so I'm not interested. If they change the tariffs I'll think about it. 
You have all the right ideas, and good on you for wanting to sort this out for your wife. 

Am running 2x 5kW Sunsynks with 6x Pylontech - and am generally happy with my system.
Yes, I do have a small issue with my system in that my slave has a higher battery draw when the system is connected to the grid. But I would call it more annoyance than issue. I have raised it with Sunsynk and they want me to send in both inverters to be able to replicate the issue - and to me that has not been worth it. The issue only presents when connected to the grid, and I am manually disconnected from the grid 95% of the time - so it is not bothering me really.
Other than than, the system is rock solid and absolutely stable.
I would recommend 2x 5kW over 1x 8kW/10kW to get the additional MPPTs for greater flexibility as well as redundancy in case there is a fault on one inverter.
Batteries and both inverters connected to a common bus bar
From what I understand, it is best to split PV strings across both inverters - e.g., rather have 1 string on each inverter instead of 2 strings on a single inverter and nothing on the other
I would probably go with 1 battery and additional panels. I think you will otherwise struggle to get you batteries charged
Your sparky will need to check. But if you install a 2nd inverter, then your initial inverter connection should be fine

I have 2 x 5kW Sunsynk, initially I had 1 x 15kWh BSL...but that got hit by a lightning strike along with both inverters.
I now have 2 x 5kW Sunsynk inverters, with 2 x 10kWh Dyness batteries.

The system caters for 2 x households, so everything is x2 basically. 2 x geysers (3kw and 4kw), multiple TV's, fridges, washing machines, dishwasher network equipment, borehole pump, booster pump etc. everything except the 2 x ovens are on the system.

Zero issues experienced across both setups, with a single battery or multiple batteries. System just works.

Depending on your budget maybe aim for another 5kW inverter and more panels...

Am running 2x 5kW Sunsynks with 6x Pylontech - and am generally happy with my system.
Yes, I do have a small issue with my system in that my slave has a higher battery draw when the system is connected to the grid. But I would call it more annoyance than issue. I have raised it with Sunsynk and they want me to send in both inverters to be able to replicate the issue - and to me that has not been worth it. The issue only presents when connected to the grid, and I am manually disconnected from the grid 95% of the time - so it is not bothering me really.
Other than than, the system is rock solid and absolutely stable.
I would recommend 2x 5kW over 1x 8kW/10kW to get the additional MPPTs for greater flexibility as well as redundancy in case there is a fault on one inverter.
Batteries and both inverters connected to a common bus bar
From what I understand, it is best to split PV strings across both inverters - e.g., rather have 1 string on each inverter instead of 2 strings on a single inverter and nothing on the other
I would probably go with 1 battery and additional panels. I think you will otherwise struggle to get you batteries charged
Your sparky will need to check. But if you install a 2nd inverter, then your initial inverter connection should be fine

Assumptions:
all the panels are facing north, with a slope at least 15° no shading of panels with trees, buildings etc daily consumption around 10 000 Wh (based on 40% of 15kW battery remaining in the morning after a cloudy day)  
Looks like you will be good, even during winter:
https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html


 
There will be a couple of days when your battery will run flat (below 20%), but you can bridge this with a genset easily.
Just really watch your daily consumption:
With the assumed 10kWh/day it's okay (as seen above). With 15kWh/day of consumption there will be 4% of days with the empty battery. And 20kWh/day is not feasible with the current system (you would need to double the amount of panels and add another 5kWh of battery at least). Good luck!
Youda
 
 
 

Do you really have temperatures below 0°C in the room where your equipment is located? Not sure where you are located, but I would expect that even if outside temps drop below 0°C, the temps inside would remain above that. Or do you really have ice formed inside the room where your equipment is?
Otherwise I fully agree with @Tinbum. Lead acid or GEL are absolutely the wrong investment for a solar system.

They are not the cheapest, but FreedomWon LiTE are top notch.

That said, battery brands are like car brands, one person will tell you they are the best,  another will tell you they are a steaming pile.

Try to get a feel for local support for the various brands. Look carefully at the specifications - how quickly can you recharge? What is the steady load they will support, and what is the peak load they can support and for how long?

No way this is true.
PV production is usually shaped like a bell curve. So the statement that 'the panels will produce 7kW all the time during the day' will never be true. Then also factors like direction of the panels have an impact on production.
I am also based in CPT and here is the production data from my strings from this morning. Yellow is 6x 580W (=3.5kW) panels facing the morning sun and blue 8x 490W (=3.9kW) panels facing the day sun (main direction).

You can see the ramp-up on both string. The yellow one makes a steep jump around 07h30 as the sun comes over the mountain. And you can see the drops due to cloud cover on both strings.
By almost 11h30 neither string produces the nameplate capacity. So getting a constant production 'all the time' is just plain wrong.
 

No way this is true.
PV production is usually shaped like a bell curve. So the statement that 'the panels will produce 7kW all the time during the day' will never be true. Then also factors like direction of the panels have an impact on production.
I am also based in CPT and here is the production data from my strings from this morning. Yellow is 6x 580W (=3.5kW) panels facing the morning sun and blue 8x 490W (=3.9kW) panels facing the day sun (main direction).

You can see the ramp-up on both string. The yellow one makes a steep jump around 07h30 as the sun comes over the mountain. And you can see the drops due to cloud cover on both strings.
By almost 11h30 neither string produces the nameplate capacity. So getting a constant production 'all the time' is just plain wrong.
 

This gent seemingly has information that the manufacturer of the panel doesn't even know of 🙃

Output peaks during cloud edge do sometimes spike above the panel specs, but definitely not all the time.
Just stick with the manufacturer's specs. That's what can be expected under ideal conditions. 

I'll just post my recommended Pylontech battery settings, for those not having the BMS control the charge via the BMS to inverter BMS port cable. It's in dire need of redoing, but the important numbers are there: 52.5 and 51.8V.
These figures are a little higher than I use myself when adjusted for 16S (Pylontech is 15S), but were a consesnsus amongst actual Pylontech users. 

Edit: The maximum current setting is for the original 2.4kWh models. Adjust accordingly for recent models' total capacity. 

@wolfandy yes also from SA in Pretoria.
 
Yes battery current still the same between 2 and 4.
I have not yet contacted Sunsynk as my installer will handle that. But to be honest if this is not going to effect the system in future or blow it up I am going to ignore it as everything works.
The thing with Sunsynk is they are going to say send in the inverters and not doing that right now.
I am just one of those number guys and thats why I picked it up, knowing my friend he would of never noticed it as it works and that's all hahahaha 
Thanks for all the replies so far lets hope both of us get a solution or the systems does not blow up and just keep the lights on
 
 

Santa got here early this year
Time to up my monitoring and data collection game and add full backup with a small nvme raid.
And tidy it all up nicely into a dedicated DB

 

If I am not mistaken 120V or 125V
This is barely enough to get the MPPT started - if at all. So I am not surprised if you are not getting any production out of these strings
As they are facing different directions, this will not help you much. Either put all panels facing the same direction or add more panels to each string to make sure that you have sufficient voltage on each string to get the MPPT started

If I am not mistaken 120V or 125V
This is barely enough to get the MPPT started - if at all. So I am not surprised if you are not getting any production out of these strings
As they are facing different directions, this will not help you much. Either put all panels facing the same direction or add more panels to each string to make sure that you have sufficient voltage on each string to get the MPPT started

Do you really have temperatures below 0°C in the room where your equipment is located? Not sure where you are located, but I would expect that even if outside temps drop below 0°C, the temps inside would remain above that. Or do you really have ice formed inside the room where your equipment is?
Otherwise I fully agree with @Tinbum. Lead acid or GEL are absolutely the wrong investment for a solar system.