Victron vs Sunsynk

After a small incident on the forum this morning we decided to do a little comparison about the functionality of these two brands. At the end we will compile a table to show the differences.

A few rules before we start:

  1. Please state facts.
  2. If we feel your post is derailing the thread, it will be deleted.
  3. Price will be added at the end of the discussion, so please keep price out of the technical discussion. the main purpose is to first compare functionality.
  4. Sunsynk users are encourage to add the functionality that they like most.
  5. If you mention your favorite functionality, please take the time to explain it’s workings with us in detail so we can do a proper comparison.

My intention is not to prove which is better, it is to prove that you will get more functionality at a price.

@justinschoeman , @Tariqe , @Ryeman will you please share your experiences with us.

@Padraic you are welcome to share all you have read up on with us as well.

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The biggest plus-point for Victron is the accessibility to not only local dealers but repairs shops AND then the next level, contacting the manufacturer themselves if all else has failed, either local in SA or absolute last resort, Netherlands.

Second biggest is the programmability, via settings, to make the equipment do to a T, what ones needs to do.

Third biggest plus point is the programmability, the interfacing, with Victron Venus via either HomeAssistant or direct using Cronjobs.


I’ll try to make time a bit later tonight to type up more, but functionality on Victron I use frequently, and would not go without, is the remote management of the system. It gives me immense peace of mind to know that I can log into my system and make a change when loadshedding is announced, for example.

One of my favorites as well. Remote “Real time” data, not averages produced by a third party app.

Remote monitoring right up to “Firmware” level.

Remote setting and configuration off all “Local” available settings.

Multiplus Models, 1 input, 2 outputs, Quattro models, 2 inputs 2 outputs.

In the config file the user can select the max allowed current from the grid. This is especially useful when you have a generator connected to the Quattro. Both inputs can be configured separately.

I am a Sunsynk (Deye) user. Unfortunately, I can’t add much.

The Sunsynk does have some features which look great on paper (proper generator support with auto start and gradual ramp up, smart load, etc). But I don’t use any of that, so can’t really comment.

I really just use basic inverter functionality (here the time of day based settings are probably the most useful feature). I also read the inverter parameters and use them to run a basic automation system for the geyser.

So far, the system has been 100% reliable. The entire house (including geyser) runs off the inverter. Peak daily loads are about 7kW.

Factory support has been excellent (aside from the language barrier). I requested firmware changes to drive Earth-Neutral bonding relay, and they were implemented within a week and remotely installed on my inverter. They also supplied all the interface protocol documentation on request.

I have not needed much other support, but I am on the factory support WhatsApp group, and have seen how the factory does not hesitate to instruct the local agent to swap out any faulty equipment (which is fairly infrequent).

Probably the only complaint I would have is that it is a transformerless system. Without the ‘inertia’ of a big transformer, this means that power ‘blinks’ when I turn on heavy equipment (like a 3kW cut-off saw). Not enough of a blink to affect any electronic equipment, but still noticeable.

The other thing that would be nice would be remote management of the inverter. The default end-user software only allows remote monitoring, and you need to sign up as an installer to get management capabilities.

In the end, it was the cheapest hardware that met my basic requirements, but still had a decent warranty and good manufacturer support.


Very important, If you are into Home assistant or home automation, Victron offers a really big Modbus register. Quite a few registers are “read only”, but those values can then be used in automations that can “Write” to and change the other registers. It allows for endless options in control and management.

Also very important and a good point to use in this comparison. The Victron community has been running for many years, they also have a “Document” Section where all of their documents are available for download to everybody. By far the best documented product I have worked with in years.

Oh yes, and Sunsynk inverters can’t be fried by geckos. :rofl:


Now that you mention this, Victron uses a build in relay, with sunsynk you need to source a relay with a suitable rating, then install it and update the firmware to make it operate correctly.

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Nice point, lets look at how Victron controls this with the “Weak AC” setting. I will ask my friend @plonkster to explain this, he is much better with words than me.

Then when you are done, please explain “Power Assist” and “Dynamic Current Limiting as well”?

I am not going to try and explain it as accurately as you can. Thanks in advance.

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I have:
Victron MPII 5kw,
MPPT 150/35
MPPT 150/60
MPPT 100/20
Pylontech 3000x2
Energy Meter ET112

Things I like:

  • Modular
  • Parallel inverters for more power
  • Online real time monitoring
  • Remote firmware updates
  • HA/Node Red/Sonoff/etc integration (I use MQTT, Telegram, etc)
  • Support network (excellent) and community (a little slow for VE staff to answer though)

Not really like:

  • Price (but you pay for the above)

PS: I’ve done the
12V 3000w inverter (Lead Acid)
Axpert 800w - 24V (Leach Acid)
Axpert 5000w - 48V (BMV, ICC etc, LA and then Pylontech) - that was good to be honest @TheTerribleTriplet (THE DRAADKAR)
Infinisolar 3kv (BMV, ICC etc, Pylontech) - that was good to be honest


Victron supports Multiple Battery Brands and some of them have more than one type of battery, by support I mean that the battery is plug and play. The GX device recognize the battery within seconds after you plug the Can cable in. Victron then knows what commands to look for to correctly charge adn manage the batteries .

Supported batteries:

Further more it supports at least 4 PV inverters that I know off. This also means that it will scan the network for PV inverters and once it sees it, it will directly start communication with the PV inverter. It will record the readings it needs and control the PV inverter according to its own configuration.

Supported PV inverters:

The plug and play additions makes installation and support a breeze, no need to use 3rd party devices or self build gadgets to communicate with batteries and PV inverters.

And less we forget, Victron also “listens” to their customers, therein the regular “fall off a horse” easy (I’ve bliksemmed off about 6 horses in my life and I tell you, it is EASY!) automatic upgrades to all firmware AND the additions to the Venus ito more settings, to make things more manageable.

I had an Easysolar II GX, I want to comment on the service after the sale, had an issue with the mppt, sent it to Segensolar/ authorised repair shop, they could not find anything wrong, but the problem again happened the same day, I had written to Victron and luckily Jaco was in Cape Town that day, came over to the house and found the problem, then Victron found an additional, but minor problem with the mppt from the history on vrm and within a day shipped me a brand new unit, did not even wait till they got the old unit back. So exemplary service from Victron, I commend them for it…
The only reason I switched to the Sunsynk was due to not figuring out my loads properly before getting the Easysolar II, unfortunately due to covid hitting my income levels quite hard, I could not afford to add another Multiplus II in parallel, so sold the Victron and purchased the Sunsynk.

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Uuuh, that’s actually not so much for a generator, it is more for people with a boat who ends up in some backwater marina and the shore connection is really terrible. But can sometimes help with smaller generators too. Basically, the Multi tries to keep a proper power factor (close to 1), and it does this by very closely tying with the sine wave (modulating the PWM ratio in sync with the AC), and that allows it to also charge more efficiently. But if you cannot tie properly with the AC, then you can abandon this method and use a less efficient method that is more likely to accept the AC… but it affects the power factor and the efficiency: The inverter gets hotter, you actually charge a little slower.

More in line with Justin’s original mention of generator start/stop, of course you can either use an assistant on the Multi (which you would do in backup/off-grid setups where you may not even have a GX device installed), or you can use the relay in the GX device (which allows even more configuration options). It also has “test run” options. All good and well, but I do suspect a very large number of people will simply say that they don’t intend to auto-start a generator anyway… so who cares :slight_smile:

Again, the backwater marina thing. You park your really nice yacht next to a 10A shore connection, and you cannot run your AC properly because the shore connection keeps tripping! So you configure the Multi to draw 10A from the shore connection and add the rest from the batteries. When the loads drop below 10A, it charges the battery with the difference.

People have also used it to safe money on generators. Instead of buying a big one that can handle the peak consumption, they buy a smaller one and the cover the peak with battery power. A smaller generator running at 60%+ load does much better than a larger one spending too much time at lower power levels.

When a large load starts, it helps your generator by powering the load from the batteries and then slowly transferring it to the generator.

Basically, there are a number of options to help with generators, because to get a really clean sine wave you need a nice big Diesel one and not everyone has that…

The Sunsynk :


  1. easy to set up,
  2. connects easily to popular batteries via the CAN port.
  3. “time of use” is a great feature
  4. During summer i was consistently running 3.5-3.8 kW loads on my 5 kW inverter, would not de-rate, the fan would come on periodically but once the inverter cooled down to a certain temperature, the fan would shut off
  5. “Smart Load” function is connected to the pool pump, automatically switches it on/off depending on available pv/battery soc


  1. Victron vrm spoiled me, Sunsynk thru the third party app is 5-10 minutes behind, but I am used to it by now, don’t bother looking at the data that much any more.
  2. No remote control, but as I am not a tinkerer, so don’t mind, as the system works flawlessly.
  3. There are a few people on the various forums that have become decent experts, but you cannot get much help from the manufacturer, or, luckily I have not had a problem so far.
  4. There is only one person in all of South Africa working on the inverters, so not like Victron at this stage, hopefully it will change, time will tell
    So far the Sunsynk is working great, I like it a lot.

From those descriptions, “Power Assist” and “Dynamic Current Limiting” are available on the Sunsynk - but only on the Gen port (not grid). But they aren’t given any fancy labels - it is just the basic generator port functionality.

Ai tog, but we use it for the generators every single time with the small generators, so i was merely asking about how this is helpful in generator use and for system configuration for generator use.


In hindsight, I may be wrong. I think the original use case was something else, but it matters little. It is an important workaround for generators. Didn’t mean to imply it should not be used :slight_smile:

I am still new to 5kw Sunsynk, installed and running since Feb 2021 with a 7.4kw SolarMd battery and 4kw of Panels, (Started off with axpert about 2 years ago, and no experience on the Blue stuff apart from a MPPT used for the camping equipment)

What I like

  1. I did a DIY install and found it Quite easy to setup initially with AGM batteries and later the 7.4 SolarMd battery.
  2. I like to tinker and the option of having the RS485/modbus interface works great for me, so much that I hardly ever use the Sunsynk Solarman app anymore.

    Monitor all parameters that you can see on the display, and storing this in influxdb
    30s updates for key info with dashboards via Grafana
    Can remotely setup and change some of the setting I have coded (just not done all of them but only the ones of interest to me for now)

  3. Using the “grid peak shaving” setting to smooth out peaks - use the battery “spare capacity” for anything over 2.5kw load on total load (Essential + aux + non essential)
  4. Aux load works great: Have setup the spare geyser with 1kw element and Poolpump on the Aux load ,

    Sunsynk control the “no 220v power” cutoff but does allow me to run even if there is loadshedding but sufficient capacity.
    Node-red further control using the geyser and poolpump optimally when on 220v

What I do not like:

  1. The fan noise - not the loudest noise but definitely noticeable under load (have added a small 12v spare fan I had to keeps thing a bit cooler)
  2. Daughter complains of very high pitch “soft” type of sound when near the unit, but this is not noticeable to me and unit is in garage thus no issues to family and no complaints