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Multiplus ESS, one MP2 for full ac coupled ESS, two and three only for charging


I'm planing a new Victron ESS system in the near future. Currently running one MP2 ESS AC coupled with 3 Phase SMA PV and two Victron MPPT (grid export) at another location. So I know how that combination works.

The now new planned system must handle a 28 kwp SMA PV system and a 45 kWh battery. I don't need backup power or anything on the AC Out of the MP2s. I only want ESS AC coupled with grid point to 0 for 0 energy costs (in the summer times a least). Neither are MPPTs planed at the moment... 28 kWp AC coupled solar is plenty for now. My plan for now is:

- Get three MP2s 5000 (one Cerbo or one MP2 with GX included...)

- Set one MP2 as ESS single phase (like the system I already build just for grid point 0)

- Set the two other MP2s as charger only devices

Is this possible? Having three MP2s but using only one for single phase ESS and the two others only as charging devices?

Why the hassle? Im living in germany. Energy cost isn't cheap here and having the three phase ESS running all the time will cost quite a bit. Also we are regulated for a max different load on different phases at around 4.6 kw. So I can't just buy one MP2 10000 or 15000 and call it a day. And charing a 45 kWh battery just with one 5000 unit will not cut it either on some days when the sun is only out for a couple hours at peak power.

In particular when I

a) dont need backup features other than maybe the router and a NAS system hanging on one AC OUT of the main MP2 and

b) I don't need more than 3-4 kw max power to balance out the grid point to zero.

Knowing that, I think keep running the other two MP2s all the time for doing like nothing is unnecessary.

If my thinking isn't possible, are there other options. Like charger only devices which can communicate with victron systems? I searched at that topic already for quite a while but haven't found anything usefull. Only some regular charing devices which then would need to push there information via modbus to the victron system which would include some manual coding... Also buying two MP2s just as charing devices isn't cheap either. All in all in the end the project is propably more a fun project than actually saving money.

So im just curious if something like that is possible or if im having other options?


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