jacquesretief

Alright, I think I've figured it out, and it's a lot simpler and quicker than assumed:
Connect a reliable multimeter across your battery bank. It might be a good idea to cross-reference with another meter. PF - This one is optional but will reset all settings to default. Set your preferred settings again via WatchPower or whatever you use. Skip this to just do calibration. PSDF - Enter calibration mode PBATHnnnn - Set the "high" voltage. In my case this was PBATH2665, as my meter reported 26.65V. Turn off mains supply to inverter so it's running off battery only. Let it run for 10-15 min to get a sufficient voltage drop (make sure you have a decent load). PBATLnnnn - Set the "low" voltage. In my case this was PBATL2630, as my meter now reported 26.30V. PMID - No idea what this does actually, but did it since it was included in the steps in the protocol doc. PSAVE - Save calibration. Turn the mains supply back on and let the batteries charge for 10-15 min. CF11 - Turn on both fans. PBFnnnn - Set the battery voltage with both fans running. Consult your meter again here. PSAVE - Save calibration again. This will turn off any running fans that are not needed. QPIGS - Run this one a few times in a loop, and compare the reported battery voltage with the reading from your multimeter. If all went well, your inverter's reading should now match the reading of your multimeter.
After the above process, my batteries began to charge properly and topped out at a perfect 13.60V per battery (27.20V total). Once they reached 100%, the inverter entered float mode and they settled at 13.50V each (27.00V total). The inverter was reporting correct battery voltage throughout the charging process. For reference, I'm using 28.20V for bulk, and 27.00V for float.
I will check the readings again this evening for any drift.

The V+ is cheaper but too noisy.
The 3.0+ (non V version (v for value)) is quiet and customer is happy and works perfectly with 2x hubble s100. The inverter sits in the dining room.

Another customer has a V+ and this one sits in the garage with the cars where it can make all the noisy fan sounds that it desires where it is away from people.

That one too I have connected to hubble S100 (2x) and works like a dream (5 hours with a barfridge, 2x standard 200-300w fridges, 1x freezer) with some life still left in the batteries.

On both installs I have installed a battery balancer from Geewiz to keep the voltages across both batteries consistently the same.

Could you please show me what is underneath...the lid?

Problem solved ... fuse and wiring on the pole replaced "again". 

I have a voltmeter permanently attached to my grid side. I notice quite often after load shedding my voltage is low - around 195V or so, then it picks up.

Mmm... running 2x Growatt SPF-5000ES and they don't truly blend for me. In the early morning if my batteries are low they put the Solar to batteries and run the loads from Grid. I don't really see that as blending really... not like the way I understand SunSynk does.
I am actually looking to replace my Growatts with probably SunSynk (likely 2x 5kw) as a Victron 8Kw with separate MPPT units is a little costly. I am looking to run 4 strings of panels.

So the kettle draws 2 kW for a couple of minutes, will draw from the grid, look at loads that are used for a while like geyser, washing machine, tumble dryer, dishwasher, air cons, plus then you need over 10 kWp of panels, do you really need all that

Here is my As built with legal certification

Thanks Leshen for your assistance, way above and beyond. Better service than from my installer, and I paid him😢.
 

Thanks. I suspected that would be the reason that I did not see many alternatives... 
 
Do you know how to get access to the relevant regulations? I would also like to learn what the rules are regarding these installations. I've met too many unreliable electricians to be trusting them without learning things for myself as well.

This is a hard question to answer actually.
Firstly there are a lot of variables, like the exact orientation of your panels, the number and type of panels, their angle of tilt etc.

Secondly my system seldom produces it's theoretical maximum: either because the property's demand for power is less, or because bad weather reduces it's output. My system is set to not export. So on a sunny day, it will generate maximum PV until the battery is charged, then will generate just enough to keep the house running. I think I've seen about 20 kw/h a time or two, but most clear days I won't get near that because the demand isn't there and so the system doesn't generate power it can't do anything with.
 

I recently found out that the sunsynk 3.6kw is fanless, exclusive to SA model, but it is the same price as the 5kw with fan 🤨

The important thing is that you know your loads and the maximum you will need at any given time. I think this is important.

Oh that would be the first thing I'd do. I assume there is no downside to doing this?
I heard an amusing story once of how a building brought their bill down substantially by installing a R500 timer device.
They had two air-conditioner units that started simultaneously, causing a very high demand peak. The timer device they installled simply spaced the two units apart by a minute or so, causing a much lower demand and a substantially reduced bill. Remains one of my favourite engineering stories 🙂
 

Hahaha its the Hubble. As tempted as i am there's no use in opening the box at this stage. And its farkin heavy

@jacquesretief I am not sure how you would be cycling your battery down to 50% 3 times a day, we have one cycle of day/night in a day and during the day a solar system will generally produce more power from solar than the house will be using and will power the house and charge the batteries during the day. There may be a short period of using some power from the battery if the load is high and the sun goes behind a cloud or something but that is the exception rather than the rule.  
The way I see it, the ROI on current battery purchases is extremely long and purchase of them only really makes sense at the moment so as to avoid load shedding or if you want to go off-grid.
According to my calculations, If you are only considering how much money you are saving money that you currently pay Eskom,  it is will take more than 8 years to pay of the batteries. 
ROI on a grid-tie system is generally much shorter and usually works out at around 3-4 years depending on what your loads are and how many you are able to move to daylight hours when the power is "free"
In SA at the moment, cost of power during load shedding is considerable  and softer considerations such as convenience of not having to run around switching on generators need to be taken into account. Considering that a 6kw generator will use 2-3ltrs of petrol an hour and average load shedding is about 2.5hrs, I used a cost of R100 for fuel per load shedding. Assuming that I use the generator only once per load shedding day, we have had a total of 47 load shedding days this year, total cost would be R4700. When you start adding those number to the equation it starts making a lot more sense to ensure that you can keep your house powered over load shedding using solar power & batteries, this is not as much an issue during the day when there is loads of solar power but I used my load in the evenings, between 18:00 & 22:00, when there is no power coming from the panels, to calculate the amount of storage I needed to make it through without starting my generator.
To maximise the return on my batteries, I keep them 90% charged until 22:00 in case of load shedding and then power the house from then until the sun comes up in the morning at which point they are down to 20% and ready to be charged up during the day.  
Good news is that the price of power storage is only going one direction and that is down. The new Tesla 4680 batteries, coming online in 2022, are estimated to reduce the  battery storage costs by 40% and that is going to put a lot of pressure on the prismatic cell battery manufacturers to reduce costs on their cells. 

If the battery is rated 5.5kWh that means you can take out 5.5kWh if you discharge it from 100% to 0% SOC and will "use" 1 cycle.  If you do that 3000 times you will have taken out 16500kWh.
If you discharge it from 100% to 50% SOC you will take out 2.75kWh and use half a cycle.  If you do that 6000 times you will also have taken out 16500kWh.
Correct.  But you cannot use them alone - they need to be charged, and inverters are required to generate the AC.  In practice PV panels and inverters have finite lifespans, so the effective cost of using them is not zero.
 

Thank you for everyone's replies and advice!
After taking a long, hard look in the mirror, and shedding a tear for my bank account balance, I have decided to beef up the system up-front rather than wait to expand. The way things are looking with Eskom now concerns me. So I eventually decided it was worth it to get as much initial independence as I can afford. Hopefully this will pay off in the future.
My new setup idea looks something like this:
8kW Sunsynk 3x BX51100 Dyness batteries (15.36 kWh total) 12x 470W Jinko Tiger (5.6 kWp) I went with the bigger inverter after all, with the idea that it would be more future-proof. The batteries I got on a BF special - I couldn't find a better R/kW ratio so I went ahead and bought them already. Some recent threads have made me a little more hesitant to use the Hubble's NMC chemistry. 😅  These BX51100 models have 0.5C recommended and 0.75C max according to their datasheet. The max draw of the inverter is slightly above the recommended 0.5C, but I doubt the small difference will really cause a problem. Especially since I will rarely, if ever, hit the full 8kW anyway.
Now for the panels, does anyone have experience with the Jinko brand? Are they reliable? I found those panels at a better R/W rate than the JA Solar ones I initially thought of, but it's always good to check if anyone has bad experiences with them first.
Since this is turning out to be quite an expensive investment, I want to double check to make sure I am not making any mistakes here. Which brings me to another question - does anyone know reputable solar installers who operate in Pretoria North? I still kind-of want to install the system myself, but a lot of the warranty documents I read mention that you need a qualified solar installer... so I'm not sure what my options are here. Since installers make their business actually installing, I don't know how many are interested in just consulting / checking the installation for certification afterwards.

Jacques and I live and work in Waterfall, KZN.

I've done a few Mecer + lead acid load shedding DB installations and now taking a big step towards solar and larger inverters and its scary and exciting and I'm thrilled to introduce myself and HELLO EVERYBODY! 👋

So I was wondering about using batteries as a way to not only have a storage of energy but as a way to offset electricity cost.
Currently I am paying R2.0866 per kW of hourly usage or converted R0.002c per watt of electricity used in an hour.

An AM-2 Hubble Lithium Ion battery sells for R26 000 @ 3000 cycles used at 100% DoD.

Consider the calculations below:

5.5kW = 5500W
5500W * 3000 cycles = 16 500 000 watts per full lifetime of one battery.
R26 000 / 16 500 000 = R0.00157 cents per watt. That is 24.5% cheaper than Ethekwini's tarrif. At 6000 cycles (50% DoD,) we have twice the amount of cycles, therefore twice the amount of savings. Almost 50% cheaper!!
We know that tarrifs  have been on the rise. Unless municipalities pull thumb or already pulling thumb and considering sourcing electricity independent of Eskom we can have hope. Another source of hope is that individual sources of power production have passed legislation to self-generate from 1MW to 100MW and I remember recently reading in an ethekwini newspaper that bi-directional meters are being highlighted to being rolled out where you can sell power back to the grid.
We really can save the earth by taking these small steps away from coal/fossil fuel burning to harvesting natural sunlight energy.

Manuals for all products can be found here.
Sunsynk also released two training manuals in January 2021, one is more generic, and the other more product specific. I can't find updated versions on the Sunsynk site, but my copies are here.