Growatt MIN 4200TL-XH AC-coupling with MultiPlus-II 48/6500 ESS during grid outage

DIY
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1

Hello everyone,

I’m designing a Victron ESS system and I’d like to confirm whether my existing Growatt inverter will work correctly in AC-coupling during a grid outage.

Existing installation

-Growatt MIN 4200TL-XH

-Firmware: ALBA050101 (AL1.0)

-12 × 430 W PV panels (East/West)

,Grid-tied installation with a feed-in contract (France)

I want to keep this installation unchanged because I have a very good feed-in tariff.

New installation

I plan to add:

-Victron MultiPlus-II 48/6500/100-50

-51.2 V LiFePO₄ battery (Docan ~15 kWh)

-Cerbo GX MK2 (or Venus OS if appropriate)

Goal

When the grid is available:

Growatt operates normally.

The Victron system charges the battery from the new PV array.

When the grid fails:

The MultiPlus-II forms the microgrid.

The Growatt is connected to AC OUT of the MultiPlus.

I would like the Growatt to continue producing power.

The MultiPlus should recharge the battery from the Growatt output.

When the battery becomes full, the MultiPlus should limit the Growatt output using frequency shifting.

My questions

Is the Growatt MIN 4200TL-XH known to work correctly in AC-coupling with a MultiPlus-II?

Does firmware ALBA050101 support frequency-watt / frequency shifting correctly?

Is there any specific configuration required on either the Growatt or the MultiPlus?

Has anyone successfully tested this exact configuration?

Any feedback or real-world experience would be greatly appreciated.

Thank you!

2

I’ve got the same inverter with a Growatt 3000MIN inverter on AC out. It’s been working fine for the last 6 months. I’ve never tested the frequency shift works.

I’ve added a ESP32 to the Growatt to communicate with Home Assistant though. I can control the power output of the Growatt from there: