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mich31 asked

Backup power extension to existing battery system

Hi there,

I have the following system:

"Sonnen" ECO8 12kW storage

SolarEdge Inverter: SE9K-ER-01-ENG

9.9 kWp modules

Emergency power box from the company "Sonnen" (single-phase, not black start-capable) with mains disconnection.

Why "Sonnen": They have a LiFePo4 battery and had an attractive flat rate (ends August 2022 :( ).

Unfortunately, the system cannot start black - according to service, not with the new emergency power box, which could also do this with a new memory generation from "Sonnen". But that is not compatible with my system.

Is there a way with Victron Energy to use the existing PV with their battery?


Thanks in advance for all ideas

Mike

ESS
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sesshoumaru avatar image sesshoumaru commented ·
I am trying to do the same, but not with Sonnen but with a Fronius Inverter and Varta Element AC coupled battery. The inverter seems a no-brainer, as Fronius and Victron even have a webinar video on how to get this working.


The Varta battery will be a challange. If its not working as I expected, i could still try to do some modbus connection (as Varta supports) it and use node-red to include it into my setup (I hope I not have to :) ). Selling the Element 6 is not a option I think... I already use it for 2 years and there seems to be no market for used stuff like this.

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bbmz answered ·

This is a tough question - I don‘t know the details of your SONNEN management software and the SONNEN power measurement equipment.


What I can say: Your SolarEdge system is a 3-phase one (Germany?). If you want to have grid-failure protection and a start-procedure without grid (and also charging from PV without grid) you need 3 Multiplus 2 inverters - one for each phase (Quattro and Multiplus 1 can be problematic in Germany). According to your size of the SolarEdge system you need at least the 5kVA version.

SolarEdge and Victron will work flawlessly together (if I ignore the SONNEN system). The „envitec“ box is obsolete, because this equipment is integrated within the multiplus 2 inverters. You would also need no separate measurement-equipment on grid-connection - the multiplus 2 has sensors inside.


From my point of view I would suggest to sell the SONNEN system and start with Victron & SolarEdge - especially if you don‘t want to program things by yourself.

I honestly wouldn‘t expect that the combination of two independent battery-inverters (AC coupled) will work the way they should without an „external master“. You can program Victron e.g. via Modbus but I don‘t know about SONNEN.


If you are really interested in combining SONNEN, Victron and SolarEdge, please feel free to ask again. But then I need additional details about the SONNEN system. Does it work without the „Envitec box“? Does it have a separate power meter? Is it limiting the SolarEdge system or is excess feed into the grid? Is the inverter (SONNEN) one-phase or 3-phase? What are the charging/discharging rates? …

The only possible sequence for a grid-independent system would be: grid -> Multiplus 2 -> SONNEN -> SolarEdge. But this rises the questions, if the SONNEN can work behind a Multiplus 2 and if the multiplus 2 can work in front of a SONNEN?

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mich31 avatar image mich31 commented ·

The Envitech box disconnects the system from the grid in the event of a power failure. Yes, it has a separate power meter. The excess is fed into the grid. The inverter is three-phase. Power 3300W.

Sonnen eco8/12

1661707196648.png

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mich31 answered ·

se-inverter-installation-guide.pdfsonnen_-_eco_8.0___eco_8.1_backupbox_-_installation_manual_-_22320_au492en.pdfsonnenbatterie_eco_802.pdfwm271en.pdfHi there,


Thank you for your interest in my problem. I have attached all the installation instructions from the devices I have installed. I had the instructions for the WM271 translated by google - don't be surprised! If it helps, I'm happy to take pictures of the connections, if necessary I'll also open the devices....

The instructions also include wiring diagrams.


At the moment, the emergency power box only supplies the house with one phase, which would be sufficient for me. would you still have to install 3 Multiplus 2?


Many greetings



se-inverter-installation-guide.pdf (11.8 MiB)
sonnen-eco-80-eco-81-backupbox-installation-manual.pdf (5.8 MiB)
sonnenbatterie-eco-802.pdf (3.2 MiB)
wm271en.pdf (1.8 MiB)
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