Yellow Measure

Somewhat tricky, because of the E/W split, and you have cooling coastal winds to contend with that could cause both voltage and amps to fluctuate. You say that you have 11 months worth of data, but if you can at least look at a full 12 months' worth of MPPT data (not just power, but voltage and amperage), then you could do your calculations based on that. Also you don't say where on the Garden Route (a 300 km stretch from Witsand to Tsitsikama!) you are: minimum temps could be vastly different, especially at different altitudes, for example a ridge on the Outeniqua or Swartberg would have different lows to Storms River Mouth. This is important because minimum temperatures increase voltage, and maximum temperatures increase amperage. As pointed out by @Kalahari Meerkat the main concern is exceeding the max voltage of the MPPT which is 500V, so nothing 450-480V. Using 0°C to +2°C as the minimum gives ~52.9–53.2 V per panel, so OK even if you are on a low-ish slope on the Swartberg. 7 panels: ~370–372 V → still in MPPT operating range (425V); 8 panels: ~423–426 V → marginally over MPPT operating range, but still workable; So theoretically you can go for up to 8 panels per series string, provided that it does not get to -5°C during a cold snap with some wind (that cool coastal breeze can turn into a frozen gale 🥶). Long story short: You can safely add 2 panels to each string, provided no sub-zero temps. Another scenario worth considering, if you have the garden space, is a North-facing ground mount structure with 4-6 panels. You can use a Hoymiles or Deye microinverter or two to pump the AC to the Sunsynk's Aux port.

Indeed, but now we are comparing two totally different metrics 🙂 and yours has a whole lot more variables. My best month this year was May, then again I have been off grid since December. But I also upgraded my battery bank in March, and started deeper cycling (and evening usage) in May.

Here are my Port Elizabeth weather station's graphs, for the year to date (1 Jan 2026 to 24 June 2026): Ignoring the dip in March/ April and the spike in May (due to various comms issues), you can clearly see peaks of well over 1000W/sqm in January vs barely over 500W/sqm in June. Here is a graph of the last 12 months (25 June 2025 to 24 June 2026): So in my experience, with both coastal and inland installations, it is generally a drop of around 50%.

In Gauteng my install of just over 6000kWp is at a 26 degree angle, and about 5 degrees off true North, and I have noticed quite a drop-off this winter, possibly due to poor air quality. That is over and above the cloudy weather that we have experienced in Gauteng. It is confirmed by my weather station, which measures W/square meter, here is the graph for the year to date (1 Jan 2026 to 24 June 2026): In January I was regularly getting peaks of over 1000W/sqm (even 1171 in February), this has now dropped to my best peak in June at 576W/sqm. Here is a graph of the last 12 months (25 June 2025 to 24 June 2026): So yes, it's is quite a significant drop-off from Summer to Winter.

Hubble batteries are great, and I am most grateful for the Powerforumstore's recommendation at the time. I have 3x AM2s in parallel since March 2022, still going strong at 103% SOH. Not bad for over 4 years, 871 to 986 cycles, cycled daily and not a days' worth of trouble. 😎

So that settles it then. I guess that it's an opportunity for an installer with a spare 8K SS to loan/rent it to you, and send your unit in for repairs. But here's another plan: how about buying the new Solis S6 Pro 8K that Powerforumstore currently has on special, install it and then you can send the SS in for repair and sell it when it comes back? It's a way better unit, with far better support.

True. If Sunsynk want to be perfectly correct about it, they should be insisting on a datacomms technician to attend the call, because it has to do with the electrical signal characteristics of the RS-232 interface. I am willing to bet that the vast majority of electricians have never encountered it before, making them just as unqualified (and ill-equipped) as you. Can you imagine if the problem was not power, and they need him to plug a loopback connector in and run a BERT? Or to measure the delay between RTS and CTS? 😀 @PearlJam I know the old field "engineering" motto used to be that a layperson with enough of spares could diagnose and fix just about anything, but it does have its limits, which brings me to my point (and I guess Sunsynk's as well): If there is a fault condition with a sufficiently high voltage (say 40V) on pin 9 or 5, it could have smoked the dongle, as well as the new one that you plugged in. If you measure between pins 9 and 5 (ground) you should get +12V. Even less (down to 5V) should power the dongle, but if it's lower than 5V then it won't. If it's way high, then not only is the board faulty, but you have 2 unserviceable dongles as well. 😬

AC or DC?

It looks like higher import tariffs on renewable energy equipment are being planned, in the name of "stimulating local production of components in the renewable energy supply chain". "One of South Africa’s largest electrical product distributors warned that planned import tariffs on renewable energy equipment could keep solar self-generation out of reach for lower-income households. The International Trade Administration Commission (ITAC) recently published its preliminary determinations after a year-long review of import tariffs for solar, wind, and battery components. ITAC recommended that the trade minister align South Africa’s import duties on renewable components to World Trade Organisation rates. In many cases, the tariff rate is 15% of the declared value of the goods. South Africa already imposed a 10% tariff on solar panels and modules in June 2025. ITAC also recommended that the minister impose an additional 15% ad valorem duty on assembled lithium-ion batteries. The measures are aimed at stimulating local production of components in the renewable energy supply chain, balanced with ensuring local deployment of renewables." New import tariffs will reserve solar power for rich Sout...One of South Africa’s largest electrical product distributors warned that planned import tariffs on renewable equipment could keep self-generation with solar out of lower-income households’ reach.

🥱 I rest my case.

I take great pride in paying all of my bills on time. Clearly, you did not bother to read my (albeit lengthy) post before launching judgement and ad hominem attacks. A pretty poor reflection on your ability to read with comprehension.

BTW I have counted at least 5 AI bots and one AI spammer in this thread, no idea who funds them or what their intentions are : SASSA UPDATES brockbat3 Shakeel4811 MEPCOMIS KellyMichael SASSA

I did my humble little solar install in August 2020. At the time I had around 980kWh credit on my prepaid meter, which for about 4 years I hardly ever used. Around 2 years later (circa 2022) City Power sent their "auditors" in to check the meter. They left with no findings. Then came 2023, where they upgraded all the prepaid meters to "Smart Meters" in the HOA. When they came to mine, they said that they could not upgrade it, because there was over 500kWh on the meter and they were limited to transfer credits of 500kWh and under. So I was overlooked on that upgrade. I then decided to use my credits, after all, I had paid for them and they were not doing me any good sitting in the meter. So every month I used a few kWh, and I started neglecting lifestyle changes that I had made back in 2020, like not roasting a small eisbein at midnight when I got the munchies. The "auditors" came and went a few more times, and the prepaid meter's crypto key update was also duly performed in 2024. Fast forward to December 2025. I was going away for holidays, and my prepaid meter showed less than 1 unit left. I did not bother topping up because I would not be there, and my system doesn't need the grid, but I didn't budget for the inverter pushing some back to the grid, which it usually does when a big load stops, and which the meter counts as usage. Around 28 December I noticed that the grid had disconnected, and upon returning home on 2 January 2026, I tried to purchase electricity, but no go, I was advised to call City Power. When I called them, they were extremely unhelpful, telling me that I needed to come in to see them. I drove over to City Power's offices, which was in disarray. As luck would have it, there was a big power outage, and they had no power, nor any backup, and the ETR was unavailable, so all visitors were told to come back another day. I insisted on seeing someone, but they said that all staff had gone home due to the power outage. I stuck to my guns, and told them that I would not be leaving. They eventually extracted a surly and most unpleasant Marxist drone The Borg from his office. He listened to my story, then disappeared back down the dark corridor. After 45m of waiting in the stuffy, unlit foyer, I went hunting for him using my cellphone flashlight. I found him sitting in his dingy, unlit office, staring into his laptop. He grunted at me, and motioned me to sit down. He asked me why I was not buying electricity from them. I repeated my story again to him. He then asked for my rates and taxes number, and proceeded to do checks on my CoJ bill. Finding nothing amiss there, he told me that he would not reinstate my meter until I paid him a R15,000.00 "fine" for not using electricity. I protested, and he scowled at me. I scowled back. Another round of argument, where he changed his story: It was now no longer a "fine", but the R15,000 had to be paid because that was what a smart meter would cost. Yet another round of argument. The situation was beyond bizarre, here I was arguing with The Borg about why I should not be "fined" for not using City Power electricity, whilst sitting in an unpowered, unlit, stuffy City Power office. Eventually he conceded that he would "raise the matter with a senior manager", who was on leave at that time, and get back to me. Seeing that it was going nowhere, I resigned myself to my fate, went back to my 2020 lifestyle of frugality, and started pricing batteries. Needless to say, The Borg never bothered to come back to me, and I didn't bother begging him to either. I placed an order with Wimpie from The Powerforumstore, and soon my batteries arrived. I decommissioned my 3x US3000 Pylontechs and donated them to my brother, and installed my new 32kWh storage. I am very happy, because not only have I defeated Marxism and The Borg, but I can now roast a leg of lamb and a few Eisbeins at midnight again. Bon Appetit!

Is this special still on?

It is not often that you and I agree, so I double-checked just to be sure 😁 Spot on! Yes, or it could the the form of an inverter that is pre-wired, mounted against the wall, and ready to pump electrons at the flick of a switch (or two). That's what I would refer to as a "Warm Standby".