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Multiplus-II

Reduce charge current based on SOC Multiplus

I want to reduce the charge current from the Multiplus II based on SOC from smartshunt using NodeRec via Cerbo.

I have tried in NodeRed but cannot find a setting to change charge current.
Have anyone tried this?
I see that I can reduce charge current via an analog in and use an assistant in the MP, but this is not a desired solution.

Any advice?

slapperia asked
netrange edited ·

4 Answers

Two Multiplus II in series

[image]

I am working on installing a Multiplus II 48/5000 at my home, where I already have an on-grid photovoltaic inverter SMA Sunny Boy 4kW and I have some questions I haven't found answers anywhere:

1. Is it possible to install two Multiplus II inverters in series (one of them connected to the other critical loads output) with non-shared batteries? How should I configure them? That would enable me to add a new Multiplus II in the future with another new battery on grid-parallel mode connected to first Multiplus II critical loads output.

1.1 If 1. question is possible, should I configure second one to not exporting to grid? Or first one could use frequency shifting (or similar) to control how much energy could export the second one?

1.2 Continuation of 1.1 question. Would be possible to have SMA Sunny Boy 4kW connected to the same critical loads output than second Multiplus II, having both controlled by frequency shifting? Or that is not possible as maximum power would exceed Multiplus II maximum power?

It appears a similar configuration could be done by using CerboGX large firmware, to be able to use Node-red to control some inputs:
- first Multiplus II critical loads frequency (could be updated depending on first Multiplus II is able to receive more power from critical loads or it cannot accept many more
- first Multiplus II AC In grid status (availabe/not available)
And to be able to control some things:
- second Multiplus II power exportation limit, being configure to 0 power exporattion into second Multiplus II if grid on first Multiplus II is disconnected

I've seen some other questions about similar solutions, but they were trying to control batteries load between two Multiplus II at the same time at the same battery load. I'm not interested on that. What I'm looking for is to:
1. If second Multiplus II (with AC In connected to first Multiplus II critical loads AC OUT) has batteries fully loaded, then it will share power with the other one if the other requires it; if the other doesn't require it and external grid is connected, power could be exported to grid; and if the other doesn't require it and external grid is disconnected, 0 power export should be configured into second Multiplus II
2. If first Multiplus II (connected to grid and with second Multiplus II connected to it's critical loads AC OUT) has batteries fully loaded, if second Multiplus II requires power, first Multiplus II can provide that power as if it were coming from real grid

tcircuns asked

0 Answers

No Output nodes available on multiplus

Hi! Just started a new Node red system on a Cerbo with a Multiplus -II 3000.

I've used both Node red and Multiplus-II before but with this installation its fighting back.

I can read input nodes from the multiples just fine, but when I try to use an output node on it, there's is none. The Solar charge output node works just fine.

What am I missing? The firmware is 481 (Newest is 489)

Skærmbillede 2021-11-02 kl. 13.55.54.png

philipr asked
philipr answered ·

2 Answers

Force charge/discharge of Multiplus using VenusGX & Node-Red

What am I trying to achieve?

Charge the battery, or discharge the battery based on external input (via MQTT, but ultimately based on variable electricity tariff status)


I am up and running in Node-Red on the Venus GX 'large' image and am able to set the Multiplus to the following modes;

[image]

However if I set the multiplus to 'charger only' it obviously won't charge if I'm not in a scheduled charge slot.


If I set up a scheduled charge slot to be active at all times, then I can charge / not charge on demand by setting the 'Disable Charge' flag to either 0 or 1.

[image]

However when in the 'don't charge' state, it also won't discharge the battery as I'm in a scheduled charging slot.

I've tried setting the AC power setpoint instead of charging within a scheduled charging time, but it doesn't seem to do anything if I try the following;

[image]


Can anyone offer any recommendations on how I can switch between charging or discharging to meet my requirement?


homestorage-77 asked
russ commented ·

1 Answer

Help with using Node-Red with Venus GX

Could anyone please give me a bit of support in gettig started with Venus GX interfacing via Node-Red?


I've got Node-Red installed on a Raspberry Pi & am looking to switch on / off my Multiplus II based on certain input conditons.


I've loaded in the Victron nodes to Node-Red but am stuck on step 4 of the Installation Instructions;

https://github.com/victronenergy/node-red-contrib-victron#Installation-and-Usage


enable d-bus over tcp in your Venus device if you want to use dbus over TCP, otherwise skip this step. Edit /etc/dbus-1/system.confand add the following directly above <policy context="default">:

  <listen>tcp:host=0.0.0.0,port=78</listen>
  <auth>ANONYMOUS</auth>
  <allow_anonymous/>


How do I actually go about doing this? How to I connect to the Venus GX in a way that allows me to edit the files?


Any advice of next steps would be greatly appreciated too, as the instructions are not clear for me.


Many thanks in advance

homestorage-77 asked
Mark commented ·

1 Answer

Control MultiPlus II via MQTT

Would it be possible to control a MultiPlus II via MQTT ?

What I'm thinking is to disconnect the mains in relay off between 16:00 - 19:00 this would be because on the Octopus Agile tariff here in the UK is the very expensive period. During this period my house would run from batteries via the inverter in the MultiPlus II. The control would come from Node-red.

myozone asked
homestorage-77 commented ·

6 Answers

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