3-phase MultiPlus-II with BYD LVS and existing SMA Sunny Tripower 25000 – compatibility and sizing

DIY
, , ,
1

Hello,

I am planning an AC-coupled ESS system and would like to confirm compatibility and sizing.

Existing system:

  • SMA Sunny Tripower 25000

  • PV power: 26.13 kWp

  • SMA Home Manager 2.0

  • 3-phase grid connection

Planned ESS:

  • 3× Victron MultiPlus-II 48/5000/70-50 (3-phase)

  • BYD Battery-Box Premium LVS 16.0 or 20.0

  • Cerbo GX

  • Energy Meter

Goals:

  • maximize self-consumption

  • no replacement of the existing SMA inverter

  • optional backup power

Questions:

  1. Is this configuration fully compatible?

  2. What is the maximum realistic charge and discharge power?

  3. Will frequency shifting properly control the SMA inverter in island mode?

  4. Any recommended improvements?

Thank you very much.

2

It’s possible to connect the MP2s in parallel (ACin) to the 25kWp SMA as factor 1 rule is not satisfied . Recharge while grid failure is not possible in parallel operation.

If house loads are less than 12 kW (15kVA) you can connect those on MP2 ACout for UPS operation.

For island mode with 25 kWp AC-PV you would need:

  • 3x MP2 10k
  • At least 75 kWh battery

Common setup would be

  • 3x MP2 5K
  • 10 kWp AC-PV
  • 16 kWp MPPT or 4x RS 450/200
  • 4-5x 16 kWh battery (64-80 kWh) or bigger

Look for batteries from NKON ESS Pro, GobelPower GP-SR1-PC200, or self build.