Move from Growatt to Victron

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mikemynis asked Jan 5, '24

Move from Growatt to Victron

I have 2 Growatt SPF 5000 ES (Solar Inverter+Charger combined) in parallel mode. This system can deliver up to 10 kW power out (230V) in single phase mode. I have 2 solar arrays. Each array connects to it's own Growatt. Both Growatts are connected to 5 parallel connected Pylontech US3000 batteries (48 volt).

Now I want to replace the Growatts with Victron equipment, because the Growatts have proven to be unstable and unreliable the last 12 months. I need something more stable, more reliable and more professional. So I want to switch to Victron.

But there are too many different types of Victron equipment. I don't know what to choose.

So, what do I need? Apparently I need an inverter that can deliver 10kW / 230V in single phase mode. (I have two groups behind this)

I also need to connect it to the battery bank, so it must charge the batteries during the day, only from solar. (never charge from grid). Grid must be used when solar is not available and battery SOC drops below 30%.

And I need to connect 2 different solar arrays. So I guess I need 2 MPPTs.

I was thinking of a Quattro or Multiplus 10,000VA or even 15,000VA plus 2 MPPTs. But which ones?
Or do I need two in parallel mode? I don't know what's the best combination. The Growatts are All in One. But I think Victron doesn't have AIO's.

Can someone help me out? What do I need and how do I connect them (schematic) and how to configure everything?

Thanks in advance,
Mike

victron products

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matt1309 commented · Jan 05 at 04:39 PM

Hi @MikeMynis

Massive question so I'll just answer the big parts.

Inverter: 1x10kva inverter, or multiple 5kva in parallel.

For ease of install I prefer just one unit so I'd go 10kva or 15kva but note these can't be paralleled with another 10kva for example whereas the 5kva models can be paralleled together (assuming same age/hardware revision).

I'd go multiplus unless you have multiple input power sources ie grid and generator. If you have gen and grid go quattro. If you just have grid input I would stick with multiplus (save your pennies a little).

Victron do offer an all in one Easysolar however given the size of your system I personally would go for mulitplus and separate charge controllers.

In terms of what MPPTs it depends how the PV panels are wired. ie how many in parallel (max amps) and how many are in series (max voltage). This will help determine what MPPT's are right for you. This might help:

MPPT Calculator - Victron Energy

In terms of a schematic I couldnt give one detailed enough but I prefer having central bus bars. With fused connections coming off the busbars, then a disconnect before each device.

So inverter, MPPT's and battery all connect to the centralised busbars via disconnects and fuses. VIctron does offer central bus bar type products however they are quite expense so I personally just use generic bus bars and fuse holders.

Hope this gives you a head start. Once you've narrowed down inverter/MPPT's I'd maybe watch a few install videos on youtube/victron professional website. Even if you're not installing yourself it's great for understanding the system and components.

In terms of configuring the devices I'd look into the manuals section and have a skim of multplus, MPPTs and any busbar/smart shunts you use. They have really detailed instructions. Only other point to mention is if you dont get a multiplus gx version you may need a seperate cerbo gx or similar device. I think of it as the brain/control panel of the system.

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Fideri matt1309 commented · Jan 07 at 10:54 AM

@matt1309

My understanding was that the Quattros 10kva can be paralleled. I don't know about the Multis.

Fideri

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matt1309 Fideri commented · Jan 07 at 11:10 AM

I know the Multi ii 10kva can't be paralleled. I'm not sure on quattros, think you might be right

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ejrossouw Fideri commented · Jan 07 at 01:14 PM

All stated in the Multiplus spec sheet. "Virtually unlimited power thanks to parallel (not for the 8k, 10k and 15k models) and three phase operation. Up to 6 Multis can operate in parallel to achieve higher power output. Six 48/5000/70 units, for example, will provide 25 kW / 30 kVA output power with 420 Amps charging capacity."

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mikemynis matt1309 commented · Jan 15 at 01:53 PM

Hi Matt,

Thanks for the detailed explanation :-). I checked out the MultiPlus-II 48V 5000VA. This one can be paralleled up to 6 units as @ejrossouw mentioned.

I am not interested in feeding the grid. Only to use grid when solar is insufficient.

So now I only need to add an MPPT charger to the MultiPlus II. I was thinking of a SmartSolar MPPT RS 450|200 (thanks @ejrossouw).

This one has 4 MPPT trackers, so I can connect up to 4 solar arrays. (I currently have 2 arrays, but with 4 trackers, it's extendable).

So the RS 450 will be connected to the 5 paralleled Pylontech US3000 batteries, to charge them. And the MultiPlus II will get power from the batteries and grid (when needed).

And when one single MultiPlus II is not enough for the required output (because it's only 5kVA), then I could add a second MultiPlus II.

And then we have the issue pointed out by @Mike Dorsett (thanks Mike) about the need for a Cerbo GX? So apparently that needs to be added to the system as well...

What do you think? Is this a good combination?

And how about monitoring the system? I now have SolarAssistant, and I read that it's not compatible. I also read about VRM? WHat else do I need to complete the Victron system?

What do you think?

Thanks again,
Mike

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matt1309 mikemynis commented · Jan 15 at 03:49 PM

@MikeMynis

Sounds good to me. Very expensive system you've got planned but would be awesome. Few things to note.

A cost saving measure could be multiple smaller MPPTs ie say buy one unit now and then another when you expand rather than the larger unit now however totally up to you. You can parallel mppts without issue (assuming you fuse them).

Victron system does also work with grid tie solar via AC coupling. If you're not already got grid tied inverters it's probably not the best route to go but just in case i thought it was worth a mention.

In terms of GX devices you've got a few options, an external device like a cerbo gx (or even raspberry pi if you're into them), or you get a multiplus GX model where the gx device is built into the inverter. I personally prefer an external unit as I find it easier to add/remove devices from an external device rather than digging around in the inverter/closer to dangerous wires.

If you want to parallel 5kva models you only need one with a gx device the rest can be non gx. If you're paralleling inverters i highly recommend buying them all in one go. I've built systems where second inverters are added at a later date and finding the same hardware revision/getting cable lengths correct for balancing between the two units can be a nightmare (Sometimes it's easy but I've had some headaches with it). So if you're going that route i recommend doing it from day 1 rather than at a later date.

In terms of monitoring. I've not used many other systems but i find Victron's to be one of the most open systems I've messed with. If you dont mind a bit of tinkering (node red/javascript or python) you can relatively easily integrate victron system with any other you want. even if it's not officially supported.

The GX device captures/displays live data and sends this to VRM (VRM being a cloud based service which is free). If you dont like the cloud you can make your own using grafana. VRM is really quite good though, just works. You can run node red on gx devices and access the live data/write your own code or send data to any system you can think of to be honest. Similarly you can download data in csv format from VRM (i dont have much experience with this though).

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frankmsc68 commented · Jan 05 at 05:53 PM

Hi Mike,i'm considering moving to victron equipment....Reducing a bit your actual needs to about 6kw...you could try the Multi RS Solar.It has 2mppt's with a good voltage range.If you're not interested in feeding back to the grid this might be an option,which i am thinking of going into....Everything else,i beleive, needs again more than one equipment....Best of luck,Frank

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mikemynis frankmsc68 commented · Jan 15 at 01:17 PM

Hi Frank, thanks for the tip. I checked out the Multi RS, but they don't support grid input. I am indeed not interested in feeding back to the grid, but then solar is insufficient I need grid input as well. So I think the Multiplus II might be a better choice in this case.

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frankmsc68 mikemynis commented · Jan 15 at 04:22 PM

Hi Mike,the Multi RS Solar 48/6000 Hybrid,dual mppt is/can be connected to the grid...The only thing-for the moment is-you can't feed back to the grid...you can charge though,or use it as hybrid when solar/battery energy is not enaugh.I have reduced the actual power on all my home equipment for the last years and running at the moment a 4,5kw inverter with additional 2,5kw charger/double mppt.It's a bit tight,at times,that's why i would take a fancy to the Multi RS Solar.....I have decided,though, as i'm not in a particular rush,to wait the developments for a second.....Good luck in choosing,Frank

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mikemynis frankmsc68 commented · Jan 17 at 12:37 PM

Hi Frank, yes, you are right. The Multi RS Solar 48/6000 Hybrid, dual mppt can indeed be connected to the grid. But can you also parallel two of them, for doubling the power output and the amount of MPPT trackers? I can't find info about paralleling them... If they can be paralleled, it might be a valid option for me to choose from, instead of the other idea, as I described above...

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frankmsc68 mikemynis commented · Jan 17 at 03:29 PM

Hi Mike,recordimg to the(english) data sheet a parallel config is NOT supported,but a three phase is.....Best of luck,Frank

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Modifications Space

Node Red Space

Answer 1 · 2024-01-06T20:55:30Z

Mike Dorsett answered · Jan 06 at 08:55 PM

Do note that you will also need a Cerbo or other GX device to interface the pylontech BMS data with the inverters and chargers for controll and protection. It also gives you useful system reporting functions that are essential in such a large system.

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Answer 2 · 2024-01-07T08:37:20Z

ejrossouw answered · Jan 07 at 08:37 AM

Be aware the 8 & 10kVA units deliver 6.4 & 8kW which. Depending on where you are, not all models may by fully type tested and as such, approved for parallel connection to the grid by your DNO. As with your PV, I suspect you will have to look at a MPPT RS string inverter depending on your existing panel wiring configuration and the number of panels. The MPPT sizing tools now has a search function which should help a lot to identify the correct MPPT.

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Answer 3 · 2024-01-15T18:28:06Z

Mike Dorsett answered · Jan 15 at 06:28 PM

I've not read a lot about Solar Assistant, but don't see it's need with the facility offered by the VRM portal. 2 second real time remote monitoring equals a LOT of data, 5 to 15 minutes is usually sufficient for remote monitoring. There is now also the Ekrano as an alternative to the Cerbo.

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Answer 4 · 2024-01-18T14:13:21Z

mikemynis answered · Jan 18 at 02:13 PM

Hi guys, update: I just ordered 2 x Victron Energy MultiPlus-II 48/5000/70-50 230V. I got a decent offer for them. It'll take 2 weeks for them to arrive.

Later today I will also order:
- 1 x Victron SmartSolar MPPT RS 450/200-TR (4 MPPT trackers)
- 1 x Victron Cerbo GX
- 1 x Victron GX Touch 70

Looking forward to changing everything and get the Victron system up and running. I will also get 6 x 550W panels and use 1 of the 2 Growatts for them and connect that one to an electrical water heater. And connect the house (coming from the Victrons) as backup "grid" input for this Growatt then.

That will also offload the house more. And when solar is insufficient for the water heater, then the Victrons can 'help'...

Thanks guys for your help and advice.

What do I need to configure / set everything up? How does that even work?

Kind regards,
Mike

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Fideri commented · Jan 18 at 04:04 PM

@MikeMynis Looks good. I suspect that you will also need an MK3 interface to configure your multis and set them up for parallel operation.

Fideri

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mikemynis Fideri commented · Jan 18 at 05:38 PM

Good tip, Fideri. Thanks. Will add this to the list.

https://www.victronenergy.com/accessories/interface-mk3-usb

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Answer 5 · 2024-01-18T16:10:02Z

Alex Pescaru answered · Jan 18 at 04:10 PM

Hi @MikeMynis

Congrats on your acquisition.

Now that "the dust has settled", please, can you enter a little bit in details and tell me what has been upsetting you about Growatts ?

Sorry for this question, here on a Victron site, but I am a person that likes to learn from other mistakes and knowing the downsides of Growatts maybe we can learn from them.

Thanks!

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Answer 6 · 2024-01-18T17:35:26Z

Hi Alex,

Of course :-)

Well, the biggest problem I have with the Growatts is their charging logic, which in my opinion (and those of several others in the diysolar forum), is not logical at all.

It's Chinese logic, which is not compatible with my 'Western' logic.

When solar is up, I would expect the Growatts to send power to the house (the loads) at first. Then if there's power left, charge the batteries.

But that does not happen.

What actually happens is that as long as the SOC is below a certain percentage (I set it 30%), all solar goes to the batteries. No solar energy is going to the loads.

Instead, all power needed by the loads is coming from the grid.

So even if there is more than enough solar energy (let's say 4kW) this is all used for charging. What the house needs is taken from the grid.

I want it to first power the house and with what's left, charge the batteries.

Second issue are the relatively big power dips when it switches from battery to grid power at night, when batteries are dropping below 30% SOC.

These power dips makes all equipment (PC's, NAS, TV, etc) go down.

So I needed to install several separate (APC) UPS units everywhere. They say that Growatt switching is seamless, but in practice it's not seamless at all.

Now I hear the relays in the UPSes clicking like crazy when the Growatts switch to the grid. But at least the equipment behind the UPSes stay on.

Except the NAS UPS. That one still has an issue when the Growatts are dipping. It's not a smooth switch when going from battery power to grid. It switches several times, until it finally stays on the grid.

Then when you connect the Growatts in parallel, which is possible, you MUST use batteries. In other words: the Growatts need battery power to work in parallel.

I've had several times that when battery power dropped below SOC 30%, the batteries where shut-off, to "protect" them.

And when the Growatts shut off the batteries, they cannot work in parallel mode anymore. And then they disconnect the grid as well. No Passthrough.

So when that happened the house was completely powerless and dark.

This happened several times. Once when I was on holiday. So I came home to find a lot of defrosted food in the freezer and a lot of stuff in the fridge. All could be thrown away.

Another thing that annoys me with the Growatts is that when thet SOC drops below 30%, and they go to grid mode, they still keep powering themselves from the batteries. That's why I had to set the SOC lower threshold to 30%. Previously I had it set to 15%, but then, after reaching that level at night, they kept draining the batteries. At one point even to SOC 0%, which is very bad for the batteries.

Then they have this wifi-dongle, that's supposed to be easy to install, to get data. I tried it a zillion times. It never worked. That's when I switched to Solar Assistant, a 3rd party solution. That worked immediately.

Final point: rebooting both units goes wrong 9 out of 10 times. Then they simple don't work. They don't even go into grid mode. (pass-through mode).

To fix it you must make them completely powerless. Disconnecting grid, solar and batteries. Wait a few minutes. Then power up batteries and reboot the "master' Growatt.

When it's done and it starts delivering power to the loads, only then you can power up the second Growatt.

Sometimes it works when they boot together. But most of the times you need to follow this procedure.

All these things together gave me the feeling that I cannot trust the Growatts.
At some point I even started to call them battery-killers.

Of course you can use them very well in non-professional, non-critical situations. But they are not reliable enough to feed a home. When you use the Growatts, be prepared to always be around, just in case something goes wrong.

Mike

Answer 7 · 2024-01-21T00:26:47Z

mikemynis answered · Jan 21 at 12:26 AM

Final update:

I have ordered everything, including the RS 450/200-TR, Cerbo GX and the GX Touch 70.

Now I need to figure out how to connect everything, what wires/cables I need and how to configure/setup everything.

But I think I need to create a new topic for that.

Anyway, thank you all for your help and advice

Mike

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