Victron - installation / upgrade

Hi all,

I am busy upgrading my current system and locked on replacing with a Victron.

I have decided on Victron Quattro 15Kva, paired to the following (which are already installed to my current system):

  1. 33 330w Canada Solar - panels - currently connected in a series of three panels.
  2. 3x 10kw Narada LifePO4 batteries. (total 30kw in Dec will add another 30kw)

The application will be eventually to be as self sufficient as possible but with the understanding I will always be connected to Eskom. I want to make sure that it always fully utilizes the 33 solar panels where possible during the day for essential and non essential (geyser etc) and if additional power is needed it can blend from Eskom. Haven’t decided yet if I want to use the batteries during the no solar period as they now used for pure backup.

I have about 3 1/2 years of data on my current system which tells me the following profiles:

  1. Highest load (concurrent load 14kw - ACs, geyser etc etc)
  2. Average load during “high usage periods” (bathing kids, cooking etc) - 6kw
  3. Average load “quiet times” (kids in bed, just watching TV etc) - 3kw
  4. The average load (point 3) is high but I have a large home with lots of electronics that constantly run, and some critical equipment that has to be on 24/7.

As above my 30kw battery bank was designed to get me from sunset to sun up incase of a significant outage (stolen cables, substation issues you know stuff that happens all the time here in ZA) @ a load of 2-2.5kw.

I am a geek by nature so would want as much of the technology as possible (the screen of course) but also the app connection and as much monitoring as possible.

Been doing some research and what Confuses me is all the bits and bobs you need over and above just the inverter. Thought I would ask here what would be recommended to add to the inverter for this type of system?

I have solar now with the 30kw of batteries (as per above) so this would be an upgrade on the inverter and additional equipment side.

I use Solar assist with my current system this is a snap shot. This excludes geyser stove and other non essential loads. If it provides a better view to assist.

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Wow, battery discharged is significantly lower than battery charged. Is that just the victron making some heat or the batteries themselves? It also seems very low for 30kWh worth of batteries - you only use 10kWh per day from them? I would also expect a lot more production from the ~10.xkWh of panels - perhaps that is related to the battery issue?

I would personally go with a smaller inverter (and manage loads, like converting geysers to heatpumps) or increase the panels to better match the rest. Preferably double the panels. But of course, your use patterns might dictate your choices.

Great questions:

The 30kw batteries are new (like a week). Those results are from a bank of 12 Lead acid batteries. I only use batteries for pure backup not to run loads and supplement. Might change that later when I add another 30kw in December.

For clarity there is no Victron at the moment this is a different inverter. The post was to see what components from Victron I would need for this installation. I want to stick to the Victron Quattro 15kva.

The production from the solar is “low” as its not using the full panel potential it is only pulling what is needed from the solar for the loads on the inverter, another reason I want to move to the Victron so I get full production for essential and if there is enough capacity provide for non essential loads.

I will be looking at heat pumps for the geysers etc at a later stage.

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Thanks, that makes sense.

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Well, the other bits are the GX device (ie Cerbo) which is the brains of the device. Then you will need to buy some MPPTs for your solar panels to turn the DC coming out of the panels into a voltage that can be used by the batteries/inverter. MPPTs options are mostly based on panel placement.

Thank you. Is the GX device one device or more than one per MPPT.
When you say panel placement do mean the way the wired?
How would I calculate the MPPTs needed for the 33 300w Canadian Solar panels, they currently wired in a series of three panels together.

Apart from the Quattro inverter, you’ll need a Victron Cerbo GX which can be seen as the brain of a Victron system and optionally the touch screen for it, alternatively you can just access it via your phone / tablet / computer on your local network or over the internet.

You didn’t mention the solar controller you currently have, but since you are going Victron, it will be highly recommended to get Victron MPPT solar controllers, for that amount of panels, probably a 450/100 or maybe 2x 250/100’s depending on roof / panel config.

I assume you have a single phase system, then you’ll also have to get a Carlo Gavazzi ET112 energy meter.

Then of course the communication cabling between the Quattro, MPPT’s, ET112, and Cerbo.

Do you know if that battery of yours support communication with Victron systems via RS485? This is also highly, highly recommended.

Ultimately each person’s choice what they spend their money on, just saying the Quattro 15k is huge, by the loads you listed it more sounds like you are sizing to go completely off grid. With a average draw of 6 kW, you would be able to get away with a 8k or 10k Quattro because remember, the grid / Eskom will still take care of the peaks.

Also, depending where in the country you are and with Eskom’s talk of feeding back to the grid, I think anyone installing at this stage should install NRS approved inverters, since that will be the very first condition to feed back. Whether the combo of a Quattro with Ziehl is NRS approved or acceptable is still open for interpretation, but the Victron Multiplus II models is NRS approved.

Edit, also check if your batteries can handle the discharge rate of which ever inverter you choose, also size your cabling, fuses etc. accordingly. The Quattro 15k for example will draw upwards of 240 Amps running at full tilt and you’ll have to be sure your batteries can handle it.


One GX per system. Doesn’t matter if you add more inverters or whatever, only needs one set of brains to control everything.

Most Victron MPPTs (Apart from the RS with 2/4) have a single tracker in them. You need a single tracker for a group of panels all facing the same direction. So if your roof has east/west faces, then you want 2 trackers, once for each side of the roof.

This is exactly the type of advise I was looking for so Thank You.

Let’s for this conversation assume budget isn’t my limitation rather the right system and I am sold on Victron.

Let me address some of the questions:

  1. Like I said I am a geek :slight_smile: most deifnately want the screen.
  2. I understand the requirement for the Victron Cerbo GX - added it to my list.
  3. Batteries I have are the Narada 10kw (x3) they do have BMS coms and can connect to solar assistant etc with RS485 connection. How would I verify compatability with Victron?
  4. The coms cables are they specific Victron cabling or do they work on a bus that uses normal RJ45 ethernet?
  5. I have three phase, however the house is wired on two phases only. One runs non essentials the other phase runs via the current inverter.
  6. “MPPT solar controllers, for that amount of panels, probably a 450/100 or maybe 2x 250/100’s depending on roof / panel config.”

I like to keep components to a minimum with ability for future growth, is there any benefits to go the smaller units the panel configs are

33 300w Canadian Solar panels connected in series of three panels together.

7." Carlo Gavazzi ET112 energy meter" at which point would this measure at what the solar / batteries produce or what I am pulling from Eskom.

  1. Reason for 15kva Quattro is to eventually have very little reliance on the grid, don’t think I can go completely off.

  2. I saw the announcements and in most instance could probably contribute back to the grid, worries me now that this investment with a Quattro would be certified to do this.

  3. “Edit, also check if your batteries can handle the discharge rate of which ever inverter you choose, also size your cabling, fuses etc. accordingly. The Quattro 15k for example will draw upwards of 240 Amps running at full tilt and you’ll have to be sure your batteries can handle it.”

Excellent advise thank you will go check, 240amps that would how it draws from the battery?

I see they are rated at each 10kw battery 150amps.

As long as the strings are identical electrically you can put different orientations on the same MPPT. The efficiency loss will be in the low single digit percentage range compared to having multiple independent MPPTs.

Some time after I initially installed my system I added a west facing array to my north facing array, all on the same SmartSolar 250/100 MPPT, and my experience aligns with what was concluded in this paper:

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Just be aware that the 15kVA Quattro is not certified in terms of NRS 097-2-1, so you cannot legally install it in a grid-tied system in City of Cape Town, and many other regions. Personally, I would stick to inverters on this list:

You could parallel three of the 5kVA Multiplus II units for roughly the same price range as the single Quattro. That would also mean all your eggs are not in one basket.

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  1. Ok if you want the screen, then add the Touch for Cerbo GX to your product list as well.
  2. Perfect.
  3. Usually the battery manufacturer will list in their feetures / specs that the battery BMS supports communication with inverter brands like Victron. Alternatively you could just ask the dealer you bought the batteries from.
  4. A mix of Victron specific cabling and standard RJ45 network cable, it will all depend on your final product list.
  5. Getting complicated.
  6. This will all depend on your roof layout and you’ll probably have to change the way the panels are connected anyway. If I understand correctly, you have 3 series strings so probably 11 panels each. The VOC per string is probably then arround 440v which will be margenal even for the 450/100 MPPT.
  7. The ET112 will go on the grid side right after your main breaker, it will measure how much you are pulling from the grid and communicate that to the rest of the Victron system.
  8. The 15k Quattro might just enable you to go completely off if you have the battery capacity to match.
  9. Yes at this stage I’d really go NRS approved, who knows what will happen in future. You can always go for 3x Multiplus II 5 kVA’s in parallel which will give you similar capacity than a single Quattro 15 kVA and then you are sure that you are NRS approved.
  10. Yes the 240A is what the inverter will draw from the battery, if each is rated at 150A, then the 3 of them in parallel will be fine.

Ultimately I think you should get advice from a professional who can come out to you, assess your situation and then give you installation options.
@JacoDeJongh is highly recommended around these parts of the internet, he will be able to better advise you on points 5, 6, 8 and 9, with him you’ll be in good hands.

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Thank you will reach out to him, one additional question, once reason I was looking at the Quattro was to insure I could make use of all of the panel capacity, with priority for essentials and should there be spare solar capacity it can start feeding the non essentials, example:

33 panels capacity if 11/10Kw

Essentials load is 3kw
Non essentials load is 6kw

It provides to both always prioritizing Essentials load.

Do both the Multiplus II and Quattro inverters provide that functionality?

Yes, both the Quattro and Multi have 2 outputs which you can configure for essentials and non essentials.

The difference between the 2 comes in on the input side, the Quattro has 2 inputs where the Multi only has 1.

Note the Victron inverters don’t supply power to essentials or non essentials based on solar production. It supplies both essentials and non essentials if grid power is available, but when the grid goes off then it no longer supplies the non essentials.
This does not mean that your non essentials will draw power from the grid, if enough solar power is available, then everything will draw power from solar, so you still maximize use of your solar panels whether you use a Quattro or Multi.

The 2nd output is also configurable with a firmware assistant you can program. I have mine switch off (for a minimum of 2mins) when inverter power is > 8kW for 10s, or battery SOC is below 30%. That way my non-essential stay powered for longer.

Also note that 2x Multiplus or Quattros will happily run in a 2-out-of-3 phase configuration as well.

@JN.V just want to say thank you, you have provided so much valuable input.

Understand now between the Quattro and Multi.

A random question any reason the Quattro are not NRS verified?

I am always on for having options and even though I do not see a need at the moment for an additional input, I like to have the option but to be honest not having NRS approval is putting me off.

Additional question, to keep the warentee (5 years) do you have to have the Victron installed by a certified Victron installer? I know in other industries etc this is the case for equipment.

That is a very cool option to have! Thank you @mariusm

Question I see you get a Multi with the GX built in, if you have three of them do the all communicate with each other I.e. One becomes the main brain and the others become “slaves”

Hardware limitation that also applies to the MultiPlus. The MultiPlus II and the recently released Quattro II has the necessary hardware, so they can comply. They are not approved until the specific model is tested and verified, so the MultiPlus II 3kVA & 5kVA are there, but not the 8kVA & 10kVA (yet).
The CoCT list is a relatively up-to-date list of models that do have the certifications.

The Quattro with an added hardware (Ziehl something) should comply, but haven’t officially been tested together.

Remember that “the Cape Town list” is NOT a “Cape Town” list, but actually a list of devices which comply with National regulations, which happens to be maintained by CoCT, and typically only enforced by them, for now.

You only need a single Cerbo, and then ALL Victron gear connect to that. Depending on the exact device it can get more or less complicated, but everything talks to everything else and presents a single “system”.

Edit: You need a single thing that runs the Venus software. The Multi GX does that, so you need 1x MultiGX and then normal Multis. The Cerbo is the best option if you have many things you want to connect, but the Multi GX is perfectly fine processor wise. Just IO options are more limited.


NRS approval costs a heck of a lot of money for each model you want certified. My guess is that they didn’t do the Quattro’s plus Ziehl because the Quattro’s are more suited for off-grid installations.

To keep your warranty you don’t have to have it installed by a certified installer, but your installation should of course be up to standards and you’ll have to get a CoC for it. If you don’t understand Victron systems well and you are not comfortable doing it yourself safely and to code, then I highly recommend you use a qualified person though.

Understood thank you very much