Multiple inverters with separate batteries – best way to present as one system?

[spontanbyg]

Hi,
I’m running a setup with:
3 × Growatt SPH TL3-BH-UP
each with its own ~25 kWh ARK battery
So effectively ~75 kWh total, but split across 3 independent inverter+battery systems (no shared DC bus).
What I’m trying to figure out is the best approach for Predbat:
Is it better to expose all 3 inverters separately to Predbat?
Or to aggregate them in Home Assistant (e.g. combined SOC / capacity) and present it as one “battery”?
And if aggregating:
how do people typically handle distributing charge/discharge commands across multiple inverters?
I’m aware this is not the typical shared-battery setup, so curious how others have approached similar systems.
Any pointers or examples would be much appreciated.
Thanks!

[gcoan]

Is it better to expose all 3 inverters separately to Predbat?

I have two GivEnergy inverters each with their own battery. I have simply set them up in apps.yaml as individual inverters and Predbat will cycle round the three inverters when changing mode and control them together. Note they all are set the same (although there is some smart logic on setting the charge limit).

Simply list all the inverter controls under each of the apps.yaml entries. You will probably need a custom load power and load_today sensors, examples in the docs

You might want to turn on freeze export during demand to stop them cross charging overnight

[gcoan]

part of my apps.yaml to give you the idea:

  charge_rate:
  - number.g_{geserial}_battery_charge_rate
  - number.h_{geserial2}_battery_charge_rate
  discharge_rate:
  - number.g_{geserial}_battery_discharge_rate
  - number.h_{geserial2}_battery_discharge_rate
  battery_power:
  - sensor.g_{geserial}_battery_power
  - sensor.h_{geserial2}_battery_power
  pv_power:
  - sensor.total_solar_power
  - 0
  load_power:
  - sensor.house_load_power
  - 0
  grid_power:
  - sensor.g_{geserial}_grid_power
  - 0
  soc_kw:
  - sensor.g_{geserial}_soc_kwh
  - sensor.h_{geserial2}_soc_kwh
  soc_max:
  - sensor.g_{geserial}_battery_capacity_kwh
  - sensor.h_{geserial2}_battery_capacity_kwh
  reserve:
  - number.g_{geserial}_battery_power_reserve
  - number.h_{geserial2}_battery_power_reserve

[mimikm]

@gcoan

Is it better to expose all 3 inverters separately to Predbat?

I have two GivEnergy inverters each with their own battery. I have simply set them up in apps.yaml as individual inverters and Predbat will cycle round the three inverters when changing mode and control them together. Note they all are set the same (although there is some smart logic on setting the charge limit).

Simply list all the inverter controls under each of the apps.yaml entries. You will probably need a custom load power and load_today sensors, examples in the docs

You might want to turn on freeze export during demand to stop them cross charging overnight

Little question on that. Have similar setup. Currently hybrid with two batteries is the one that sees grid and house load. AiO installed for testing doesn’t. No config problems or errors but only AiO exports when predbat sets both to export. Have you seen. Anything like this?

[mimikm]

well, it turns out that it was me:) there is significant difference between 1000 and 10000W export limit. Working as expected

[spontanbyg]

Hi @gcoan — thank you very much for your answer. I am trying to sanity-check our architecture options for a 3× SPH TL3-BH-UP setup with individual batteries.

We currently have a ShineMaster/SEM in the system, and we’re trying to decide how to evolve it with Predbat.

As we understand it, there are basically three possible approaches:

---

Option 1 — DIY SEM replacement (full takeover)

Remove ShineMaster/SEM

Build a DIY SEM box (HA + smart meter integration + control logic)

HA/Predbat becomes full system brain (meter + control + coordination)

SolarAssistant used for telemetry/normalisation if needed

---

Option 2 — VPP-based control path

Keep ShineMaster handling meter + inverter coordination

Use VPP/EMS interface on inverters for Predbat/HA control

Try to let Predbat act as external optimiser on top of SEM layer

---

Option 3 — Hybrid / observation-first approach

Keep existing SEM/ShineMaster in place unchanged

Add RS485→Ethernet gateway on inverter side

SolarAssistant reads and normalises inverter + meter data

HA/Predbat initially only writes limited or no control signals

Gradually test whether HA can safely take over control role later

---

Our main uncertainty is:

In multi-inverter SPH setups, is the single meter + SEM coordination role fundamentally required, or can Predbat/HA realistically replace it without losing stability?

Or more concretely:

do you still see SEM/ShineMaster as essential in practice, or have people successfully removed it entirely in favour of HA/Predbat-based control?

Appreciate any real-world experience — especially with multiple inverters sharing a single DTSU666.