Solis and Victron on same system

Thats’ the document I’ve got. I’ve actually been in communication with Dr. Coghlan in the past (on a different matter). He’s at the dept. of Computer Science at Trinity College in Dublin, if I am not mistaken.

Unfortunately this document does not describe something that looks anything like sunspec.

Of course it would be exceedingly simply to make a “gateway” with an ESP8266… at least for the basics. The Victron system only needs these models:

Model 1: Common (mandatory)
Model 101: Single phase inverter
Model 103: Use this instead of 101 if this is a 3-phase inverter
Model 120: Nameplate ratings.

Power limiting can be done by also implementing model 123 (immediate controls).

The required documentation for these sunspec models can be downloaded free of charge from

I’m still hoping someone will step up and do it… :slight_smile:

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The rest of the design is bi-directional. It acts like a synchronous rectifier, you might say. The PV-inverter thus ends up in parallel with the battery, and the Phoenix/Multi controls the power levels by pushing the frequency up as the battery voltage rises.

Yup, I know that reversing an inverter is easy enough (as long as you have adequate inductance). I just did not realize that it has the capability. It would be really great if you could configure the Phoenix to be a standalone charger as well, I would certainly buy one. But that is a slightly different implementation.

The phoenix works from dc alone, no ac input, what would you use to charge the battery with?

Wait, my mistake, I did not read the part about the PV inverter…

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No, you are correct in your assumption. What I mean is that it is easy to make a battery inverter bidirectional (in the low frequency topology that the victron has). So it would then be possible to plug the phoenix into an AC socket (like with a widowmaker extension) and charge a battery. That would however require it to also have to have the ability to sync to the incoming AC, which it does not have to do with an AC-coupled inverter (because the AC-coupled inverter syncs to the phoenix). But then it comes terribly close to being a multiplus, which is in an entirely different price bracket.

Thanks anyway, coding is something that goes way over my head, unfortunately.

Does this help?

SunSpec-Modbus-IEEE-1547-2018-Profile-Specification-and-Implementation-Guide-v1-0.pdf (572.2 KB)
SunSpec-Modbus-FactSheet-RevA-2019-07-web.pdf (312.7 KB)

@mmaritz , I have all the sunspec documentation, including the latest spreadsheet with the additional models for IEEE-1547. The trouble is that the Solis PV-inverters don’t implement any of it. I was hoping someone might be suitably enticed to add support… either by adding non-sunspect support for this to dbus-modbus-client (which gives you most of what you need), or by creating a sunspec conversion interface. Of course I am also fully cognisant of the reality that while we have a fairly high percentage of tinkerers here on this forum, not all of them are crazy programmers like myself :slight_smile:

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You need a crazy programmer with a) time and b) incentive. Not many around that have a) let alone b) :thinking:

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I very almost fitted a Solis in December, in fact I was ready to pull the trigger. Then I asked one of my contacts “hey how much is an ABB these days?” (short answer, about 40% cheaper than a Fronius), and then he said “I have an old one here you can have, just send a courier”. So I ended up with an ABB/Fimer instead…

And boy did I have fun with it, since I had it one week when I decided the firmware needed to be updated, and I promptly bricked it. In the end I got excellent service and I got it back into service, but I will say this: You have to be extra careful with Fimer inverters when doing firmware updates.

A feel-good story.

Bought a 2nd hand Solis.

Needed a bracket for it … emailed Solis SA for where to source one, they are sending me one, for free, from Randburg.

The fact that 1) they actually acknowledged the email and 2) actually actioned it and 3) within 48h, I’m impressed.

EDIT: This Solis idea will run totally separate from the Victron, primarily for geyser heating, when there is no LS. And IF LS gets REALLY bad, then only move it to the output of the Victron.

When? I think I will wait until CoCT is ready to buy power cause I will then have loads spare in summer, running it through my business having a VAT no, having probably bought the panels privately, the tax rebate SARS offers, OR something along those lines. Will see.

EDIT 2: I gave up with more panels for Cpt winters …


And the Solis bracket arrived, free delivery and all. Respect.

Now I can mount it to store it out of the way … :+1:

Solis support is quite jacked … so far all questions answered. Waiting to hear about the 550w Canadians if they are fine.

Got this from them on another question:

The SOP document shows a step-by-step guide to set up the AC PV inverter and Victron devices for AC Coupling. The note applies to the single-phase and three-phase setup

Solis AC Couple Victron Setup Guide v1.0-JASON_YAZBEK.pdf (990.2 KB)

Again, Solis support, their ticket system here:

… is seriously jacked.

Not only did they send me a bracket to mount the inverter, but they now found me an AC connector for it too, asking my address to ship it to.

All questions I have asked, responses as soon as they can.