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bacaryu avatar image
bacaryu asked

Multiplus 2 gx will it power from battery to ac-in

Hi,

I'm thinking to buy a multiplus 2 gx 3000 (48v) system.

The setup I have in mind is the one on the picture below. Without using any ac-out of the inverter.

My questions about this are.

1. Will it power from battery to ac-in if there is demand on my internal grid?

2. Will it charge my battery only from the ac coupled pv and not charging battery from the grid power ?

3. If the battery is fully charged will the excess power be injected to the grid?

4. If my demand is higher then the 2500 watt provided power by the inverter(multiplus 2 gx 3000 48v), will the grid provide the remaining power needed ?


I just want to maximize my generated pv power use. By storing it in pylontech batteries and using as less as possible power from the grid. If this is possible then this would be the ideal setup for my home.


27023-screenshot-20211225-021849.jpg

Multiplus-II
27023-screenshot-20211225-021849.jpg (86.3 KiB)
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2 Answers
kevgermany avatar image
kevgermany answered ·

Best you discuss with your local dealer/distributor. The suggestion above is not going to do what you want and may not conform to local regulations.

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bbmz avatar image
bbmz answered ·

Let me recap your plan. You have an AC coupled PV and you now want to add a victron for a battery system, but you don‘t want to change your panels and therefore don‘t supply your loads through the multiplus. Instead you want to connect your multiplus (like an additional load) via AC-in to the panel.

Referring to your sketch: you have no loads on the right side but an additional load-branch between multi-plus and pv-inverter.


From the technical side of view your setup is possible. The multiplus can feed-in (normally to the grid) via AC-in. In your case this „feed-in“ will compensate your loads.

Unfortunately I‘m not completely sure, if the victron ESS software can handle this „uncommon“ configuration. With external programming (ESS mode 2 / 3) it‘s definitely possible. You will also definitely need the external current sensor at the grid-connection.

Be aware that you will not have any kind of „energy-backup“ in case of grid-failure. This feature is only possible on the AC-out of the multiplus inverter.


The technical possibility says nothing about the legal situation - @kevgermany is right there. You should probably talk to your local electrician.


To your questions:

1 & 2) depends on the settings within the ESS and/or your external programming

3) Yes. The ESS has no (secure) way to reduce the output power of your inverter. If no feed-in is necessary you need a special inverter e.g. fronius, solaredge, … which can couple via modbus to an victron gateway and/or an additional management device for your PV-inverter.

4) yes

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