Multiplus Max Discharge Power via MQTT

Hi All

I’m working on a Node Red flow to change the “MaxDischargePower” of my multi during the day to benefit from PV input and then set it to a lower value during the evening to protect my batteries.

I’m using MQTT but which setting do I need to change?

  1. N/XXXX/hub4/0/MaxDischargePower, or
  2. N/XXXX/settings/0/Settings/CGwacs/MaxDischargePower

I am currently using 1. but need to double check given 2. looks like it could also be an option…

Edit: Can someone also explain the difference between “hub4” and " CGWacs" sections…?


1 Like

This is an alias for the one below. It is deprecated.

This is actually the maximum inverter power rather than the maximum discharge power (ie, any solar power coming in is not accounted for here). This is probably the one you want.

Legacy. CGwacs is short for “Carlo Gavazzi wired AC sensor” and a long long time ago (in this galaxy) before things got moved around, it was kinda sorta all part of the same thing. So the setting is still under that section, but doesn’t really have anything to do with the meter anymore.

Hub4 is the legacy name of the ESS assistant. Victron had several hub systems, hub2 and hub3 still being in use in many places (that’s where you have a PV-inverter with AC-coupled PV). Hub-1 was the first one that allowed you to DC-couple the PV, and then came Hub-4 which allowed you to run grid-parallel. Hub-4 was then renamed to ESS later. Internally the hub4 name is still used.


This is the one I had so all good…

Thanks Mr @plonkster :grinning:

So I have a change set which works perfectly when I view the settings in MQTT explorer but it doesn’t display in ESS? Does ESS show something different maybe?

Capture1 Capture2

Go out of the ESS menu and back in. That should update it. Unfortunately there is some javascript stuff going on to make it work correctly, and the code only works one way… it doesn’t actually expect the change to come from the other end. It’s not worth the trouble to fix it.

1 Like

Thanks… as long as the real NB stuff works…

Sorry to resurrect this.

  1. What’s the max for an inverter? E.g. I have a Multiplus 1 5kva - is the maximum 5000W? Is there a way to set it to just “be the maximum” (I’ve seen some people say set it to -1).

  2. Is this setting ignored when the power fail or do I need some automation/script to set it back to the maximum in that case?

In summary:

  1. 4000w for MPII 5kVa
  2. It won’t supply more and if you overload the inverter
    a. when no grid - it will shut down.
    b. when grid present it will use the difference from the grid ie. 4000w (battery) plus 2500w, for example (grid) if needed = 6500w load.

Thanks. My quesiton was more about this:


E.g. what happens if I set it to 8kw - I’m assuming the Multiplus will still just supply 4kw. And thus what should I set it to if I want max inverter (e.g. no limit) - 4kw I assume. Home Assistant doesn’t want me to send -1 via the Modbus TCP integration.

And then if I do limit the inverter power to say 500w (so that I blend 500w from batteries and the rest from grid) and the grid fails, I assume the inverter will ignore this setting (say there’s a 2kw load, will it shut down or supply 2kw with MaxDischargePower still set to 500w)?

Q1: I don’t think it does anything. The MP will just supply 4000w from the battery and the rest from grid.
Q2: I don’t know … Test it when there is load shedding - I could right now but my other half will be very annoyed if the inverter shuts down. :wink:

8 minutes away from loadshedding. I’m tempted to test this but I’m not at home either and my SO is probably gonna be quite irked if everything goes down.

Ok I bit the bullet during loadshedding. Warned the significant other that “Power may go out”. She was still asking “what do you mean” when I changed it (food in the air fryer was at least done!).


200w max inverter power

Yet more than 600w consumption

So I think it is safe to say it ignores the setting without the grid to fall back to.

I missed that question … yes, when Eskom is off, the inverter ignores all user-controlled settings. It will run till it overloads or the battery is depleted.

“Carry on at all costs” comes to mind. :slight_smile:

Yup. I was away for a week, so this answer is a bit late. But yes. Those things are “best effort”. It will just do the best it can, and ignore your request otherwise.

So if you ask for more than it can do, it will simply do the max. And if you ask for a very low limit, but there is no grid to help, then it also won’t do it. Fairly simple reason: Let’s say you have a 400W limit, and you are drawing 412W? Should we switch off? Maybe after a certain time period? Or maybe just let the battery decide? :slight_smile:

Another way to think about it is:
Any setting under the ESS menu is ignored when there is a power failure of the mains. That is because your inverter is now a UPS and not an ESS system anymore.
When the mains returns you are back to the ESS settings.

1 Like

Keep running at all costs. :slight_smile: