It has been working perfectly since its installation in May 2019, and I have been very happy with it. I now plan to increase the system by adding around 4 - 5 kW of solar panels (want to oversize for cloudy days), and have the following options:
Victron:
1x SmartSolar 150/100 (Around R13,000) - (3 in 335 W in series, 4 in parallel). Change cables to address the potential 90 A peaks (currently have 10 mm2 cabling - I oversized.
1x SmartSolar 250/100 (Around R15,000) - (new solar panels to be decided for around 4000 - 5000W)
1x Multiplus II 48/3000/35-32 (Around R18,000)
Total cost around R46-48k, some figuring out how to parallel, some maneuvering with thicker cabling. Amazing community with advice.
Deye/Sunsync
1 x 8kW Sunsync (around R32,000)
Cabling is easier. Sell existing system for credit of around R15,000 - 20,000 (Multiplus, Venus, both MPPTs).
Please comment. I am seriously wondering what to do. I know the Victron is the reputable system, but seriously? With this system I can get another Pylontech battery and literally go offgrid. I currently have 5x US3000 Pylons that generally last the whole night, sitting at around 50 - 30 % the next morning.
The Victron works perfectly as is, and I have no change-over switch. When power goes off, we do not even know it (some plugs go off). Will I need a separate change-over switch with the Deye/SunSync?
Another option is to buy a 450/100 MPPT, and connect that to the Venus using the VE.Can cable (I think this is a typical RJ45 network cable from what I have seen). Then I just keep on using my 2 BlueSolar 150/45 MPPTs, connected to the Venus using the existing VE.bus connections. Then the Venus manage the 3 MPPTs (Jaco also mentioned that I can also use the USB connection as an alternative)
Another problem raised with the Deye/Sunsync system (or issues):
I have 12x 335 W panels, and using the Deye/Sunsync, I can only use a maximum of 10 panels to prevent exceeding the maximum input voltage. I cannot use 6S2P as I have previously measured as much as 25.3A on my current 3S2P setup.
I am eyeing the 600W CS panels, that can exceed 18A, exceeding the input current limit of the Deye/Sunsync
It is discussed in the installation manual of Deye/Sunsync, and highlighted on a few other forums that the input to the two MPPT should be balanced (from what I understand is that the voltage, current and wattage should be the same??). This is quite weird.
If your usage is fine at around the ~2600W on the MP II, then I would keep that and only add more panels to the existing MPPTs or just swop them out for larger PV panels. That would be the cheapest option.
The MPPT will limit the PV usage to it’s max current rating ( I think the BlueSolar 150/45 does have a current clamp, else it will do it in software) , thus you can over spec your PV panels on current.
I have 2S2P 335W PV on a 100/20 SmartSolar (north facing).
And then I have 2S2P 415W PV on another 100/20 SmartSolar where the one string looks east and the other west which is a bit over spec for the MPPT but it works well.
Another option.
Like Louis said if you are fine with the 3kVA Multi, I would consider selling the two 150/45 MPPT’s and buying a single RS450/100 it has 2 MPPT’s built in and you can slap them with 7KW each.
Another spanner in the works… If you’re planning on parallelling the original 2019 MPII with a new one, you might have problems.
So everyone knows that parallel Victron inverters have to be identical (except for the GX model) and with the original MP that wasn’t too difficult.
But apparently the MPII range has seen quite a bit of internal changes since release. The training videos discourage combinations where they differ by more than a year. You will definitely need to supply your current serial number and have the supplier try to source a compatible one. This could be trivial, or it might not.
Correct. The 1:1 rule is only AC-coupled PV on the OUTPUT of the Multi. You can put as much DC-coupled PV on the battery as the battery can handle, and you can put as much AC-coupled PV on the input side as your regulations and cabling allow for.
This question makes me really sad. I have done a sunsynk course a few months back and the first and most probably biggest importer of Dye Sunsynk admitted in the course that their inverters can never compete with Victron when it comes to reliability and toughness.
They pointed out that the pass through rating for the 5kw is 32a and the pass through for the 8kw is 50a. They told us to install a 25amp on the 5kw and a 40a on the 8kw to ensure the unit don’t blow up under higher loads. Apparently the 5kw often blows close to 30 amp and the 8kw when you try to run current higher than 40 amp for extended periods. The 3kva/2400 watt multiplus 2 can run 30amp passthrough “for ever”
I will never ever ever replace a Victron with a sunsynk… (personal preference)
Another option is to buy a 450/100 MPPT, and connect that to the Venus using the VE.Can cable (I think this is a typical RJ45 network cable from what I have seen). Then I just keep on using my 2 BlueSolar 150/45 MPPTs, connected to the Venus using the existing VE.bus connections. Then the Venus manage the 3 MPPTs (Jaco also mentioned that I can also use the USB connection as an alternative)
Another problem raised with the Deye/Sunsync system (or issues):
I have 12x 335 W panels, and using the Deye/Sunsync, I can only use a maximum of 10 panels to prevent exceeding the maximum input voltage. I cannot use 6S2P as I have previously measured as much as 25.3A on my current 3S2P setup.
I am eyeing the 600W CS panels, that can exceed 18A, exceeding the input current limit of the Deye/Sunsync
It is discussed in the installation manual of Deye/Sunsync, and highlighted on a few other forums that the input to the two MPPT should be balanced (from what I understand is that the voltage, current and wattage should be the same??). This is quite weird.
My thought around the whole Sunsync vs Victron / Any other established brand is simply that its just too early to tell, its easy slapping a 5 (or even 10) year warranty on a product, but will it actually last that long?
Any product warranty claims go out the window if the company is not around to honor it…
It is simply too early to know whether Sunsync inverters will last or not, whereas when I was searching on the net for secondhand Multi’s I often found units that still had the old processors that could not do ESS, but that meant they where already around 8+ years old and still going strong, not to mention those are 8+ South African weather years (High ambient temps)
I think we could give Sunsynk the benefit of the doubt regarding lifetime. I mean, there’s no evidence to the contrary, and otherwise no new tech would ever make it. Some other brands have a bad reputation quickly, but it seems that people are happy with Sunsynk. There’s no reason to doubt them, and assuming your installer was qualified (re: @JacoDeJongh’s comment) and installed according to recommendations, you should be fine.
However, as far as I can tell, Sunsynk isn’t designed to scale or “grow” with you. You design the system, put the right sized inverter in and walk away.
The Victron way of doing things is almost infinitely expandable and definitely designed to grow with you. Now if you put in a Victron system and walk away you might have overpaid in terms of options you’re not using, but you’re also paying for the proven reliability.
Personally I would play it like this:
If you want to use your inverter like you use your TV, strongly consider Sunsynk. It seems to work very well for the price. (Unless you’re related to me, then I will only recommend Victron to prevent the maintenance questions.)
If you want to tinker or plan to upgrade, just go Victron. Buy less things for the same money, but be happy with the quality, reliability and expandability.
So where are you now @MorneDJ, is this the last upgrade?
Well that is exactly my point, we just don’t know, I mean they could last 25 years for all I know, I am not saying they are bad, I am just saying I won’t be the first guy to buy one
If we circle back to this thread in 5+ years and we don’t have people complaining about blown components or component availability for when (not if) a component needs to be replaced on their inverter I will gladly add them to my recommendation list.
I do however agree, you can do a whole lot worse than Sunsync (Que Voltronic)
I’d argue SunSynk is just as expandable as victron, if not more (because of lower cost). Sure, you have to buy an entire unit with everything you need for a standard setup, but at a lower cost than a multiplus alone. So you buy a 5kw unit now, later you buy another 5kw etc. With Victron you most likely will have to sell your old unit to get 2 that can parallel… (perhaps that will also be true of SunSynk in future, so perhaps it’s not a fair criticism).
Yeah, it’s tricky to predict. Victron seems to be slightly more forgiving in 3-phase setups than in parallel ones, so parallelling seems more difficult. Don’t think Sunsynk will get a free pass from the physics god.
And the new Multiplus II 48/8000 & 10000 don’t support parallel or 3-phase at all, and neither do the Inverter RS 48/6000, nor the upcoming Multi RS 48/6000 (both HF I think?). I suspect this functionality will be kept for new models of the Quattro range only, of which a Quattro II has been announced. (I don’t have any evidence for this though. Might just be timing, but my gut is telling me something.)
In any case, the expandability I referred to wasn’t just the inverter part, but the myriad of external MPPT options as well. For myself, I even include the Fronius inverters even though that’s cheating.
Edit: If you’re really thinking hard on this and can’t find a specific reason in your setup to pick Victron, then rather go Sunsynk. Don’t feel bad. A forklift upgrade will always be possible and re-sale will be viable in SA for the next 5-10 years regardless.
I guess it depends on what you are trying to do, E.g if you are trying to build a truly off grid system with minimal (or even zero) generator backup you would need bucket loads of PV and that extra inverter power would be useless.
Lets say in this hypothetical (I know it is a little extreme) we know we only need 5kVA of AC, but we are planning a 25KW PV array for those horrible overcast days.
With Sunsync I can buy 4 x 5KW (6.5KW PV per unit = 26KW) or 3 x 8KW (10.4KW x 2 = 31.2KW) units to get me there.
The Synsync cost would be around R20K x 4 or R32K x 3 so pretty much R80-R96K
Using Victron I could do 5kVA Multi R25K + Victron RS 450/200 (Can take up to 28KW of PV) for ~R33K so R58K in total. (Ok + R4.5K for a Venus / Cerbo GX) = R62.5K
The Victron cost saving is R17.5K - R33.5K
Sure you would have bucket loads of AC power / charging available if you go the SunSync route, but if you don’t need it, not only is it a waste of money, you will have 2-3 extra inverters with their own self consumption putting unnecessary load on your batteries.
I know this is me cherry picking, but it does show that at some point flexibility matters.
In my mind the pecking order is… right at the bottom you have your Voltronic Infini (the 3k and 4k models). Man those were rubbish. Then you have the Axpert, which I consider the best house in a bad neighbourhood, if I can borrow a real estate analogy. Yes, I consider the Axpert a better option than the budget Infinis… even though it cannot grid-tie.
Next up is the sunsynk, then the Goodwe, then Big Blue. Yes, I think Goodwe makes a better machine than Sunsynk. Just based off what I’ve heard and seen of them.
I can think of at least three other brands which are even more expensive (and rightly so), as we continue this pecking order, but I will leave it here
Is this what causes the churn in equipment?
I can’t figure out why people install a system and no sooner they have done this they then sell it and replace it with something else…
The fact that you say the Victron has been working perfectly and that you are happy with it has me strongly leaning towards keeping with Victron and just upgrading your system.
You can also do it piece by piece over time to help the budget a bit, do 8 more panels now, sort the wiring, do a new MPPT in a month or 2 and then only upgrade the inverter later etc.
Going with the Sunsynk solution will mean that you’ll have to do an entire system overall, plus you’ll have to do it all in one go.
You can simply add another Multi 3000 in parallel or install a 5000 and sell your 3000 to recover costs.
You can already add quite a few more solar panels to the MPPT’s you already have there is no need to upgrade to a bigger MPPT right away, but should you want to upgrade to a bigger one in future, it will be a straight swop basically.
Apart from the quality, support and reputation, the big advantage for me with Victron is the modular nature of the product which allows you to upgrade and build out your system over time as budget allows.
