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zeroco2 asked

Multiplus II & Pylontech: how to optimize self-consumption ?

Hi,

I have a Multiplus II with Pylontech Force L1, 2 MPPT 250/60, the Cerbo GX, and 6 kWp of solar panels, and I would like to use priorily my PV production... to supply the loads first, then to use the remaining power to charge the battery, and then only revert to AC-IN if the battery SoC goes below 10% (to supply the loads & maintain the battery above min SoC), all this without injecting power to the grid. What's the best mode for that ? Is the ESS mode required ? With AC-IN available, when I tried this ESS mode, the Multi was charging the battery from the grid (AC-IN) while reducing the MPPT output (the opposite of what I would like), instead of charging the battery with all the PV production while supplying the loads with the grid in "passthru" mode (the default, non ESS mode). I then tried to disable the charging mode of the inverter without much success. As I was seing "AC IN not available" warnings in the VRM, I set AC-IN1 on "grid" and the Multi started to feed the grid with the PV production. Is there an option in the ESS mode to really optimize self-consumption in the way I described, or should I revert to the hub-1 assistant (mode: prevent feeding energy to the grid), or even to a pure off-grid mode ? (when the Multiplus II has no AC-IN, the system is behaving in the way I would like, of course without being able to charge the battery from the grid if the SoC decreases below 10%)

Best wishes to all

Jeff

Multiplus-IIcerbo gxPylontech
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2 Answers
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zeroco2 answered ·

Here is what I just found about the forementionned modes (Off-grid/Factory set up, ESS, Hub-1 ) in relation to the maximization of the self-consumption:

https://www.victronenergy.com/media/pg/Energy_Storage_System/en/comparison-to-hub-assistants.html

... which states:

The notes above leaves one policy where the Hub-1 Assistant can do things which ESS cannot:

Policy 3: Disconnect from the mains when possible: For this either keep Hub-1 Assistant or (which is often a simpler and better solution): use the Virtual Switch with Ignore AC-Input.

Should I understand that, when the Multiplus II is tied to the AC-IN (public grid), if I want to use the PV output to primarily supply the loads & to charge the battery with the remaining power (and switch to AC-IN only if the SoC reaches 10 or 15%), I don't need any assistant (not even the Hub-1 and its policy #3), just to "ignore AC-IN" in the virtual switch ? (and my Multiplus II won't be in passthru mode)

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mgb07 answered ·

I have a similar set up but using the ESS Assistant and also a CT clamp (you can use the appropriate meter as an alternative to a CT clamp I believe) on the AC supply input to the property. This set up works in the order described above but I do also charge the Pylontech overnight using the schduled charge time functionality of the ESS.

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