Enhancement: Add Solax Gen2 Hybrid (SK-SU5000e) inverter type

[MJP-76]

Inverter Details

• Model: Solax SK-SU5000e (Gen2 Hybrid)
• Integration: homeassistant-solax-modbus
• Generation: Gen2 (not Gen4/SX4)
• Setup: Dual inverter (2x SK-SU5000e)

Key Differences from Gen4 (SX4)

Feature	Gen2 (SK-SU5000e)	Gen4 (SX4)
Remote control (Mode 8)	Not available	remotecontrol_power_control
manual_mode_select (Force Charge/Discharge)	Not available (Gen4+ only)	Available
charger_use_mode options	Self Use / Force Time Use / Back Up Mode	+ Manual Mode, PeakShaving, Smart Schedule
Charge/discharge control	Current (amps) via battery_charge_max_current (reg 0x24) / battery_discharge_max_current (reg 0x25)	Power (W)
Time windows	charge_start_1 (0x92), charge_end_1 (0x94), discharge_start_1 (0x96), discharge_end_1 (0x98)	Different register layout
Reserve SoC	battery_minimum_capacity (reg 0x20, 10-99%)	selfuse_discharge_min_soc
SoC sensor	battery_capacity (reg 0x1C, reported as %)	Same register, different handling

Control Model

Gen2 uses time-window + current control, similar to GivEnergy timed charge:

1. Set charger_use_mode to "Force Time Use" via select.solax_*_charger_use_mode
2. Set charge/discharge time windows via time.solax_*_charge_start_1, charge_end_1, discharge_start_1, discharge_end_1
3. Set charge/discharge current limits via number.solax_*_battery_charge_max_current / battery_discharge_max_current (0-50A, step 0.1)
4. No "Force Charge" select entity exists on Gen2 — that is a Gen4+ feature

Working Custom Definition

  inverter_type:
    - SX2
    - SX2

  inverter:
    name: "Solax Gen2 Hybrid (Modbus)"
    has_rest_api: false
    has_mqtt_api: false
    has_service_api: false
    output_charge_control: "current"
    charge_control_immediate: false
    current_dp: 1
    charge_discharge_with_rate: false
    has_charge_enable_time: true
    has_discharge_enable_time: true
    has_target_soc: false
    target_soc_used_for_discharge: false
    has_reserve_soc: true
    has_timed_pause: false
    time_button_press: false
    support_charge_freeze: false
    support_discharge_freeze: false
    has_ge_inverter_mode: false
    has_fox_inverter_mode: false
    has_idle_time: false
    has_time_window: false
    charge_time_format: "HH:MM:SS"
    charge_time_entity_is_option: false
    can_span_midnight: true
    clock_time_format: "%H:%M:%S"
    num_load_entities: 1
    soc_units: "%"
    write_and_poll_sleep: 4

Entity Mapping

  soc_percent:
    - sensor.solax_*_battery_capacity          # reg 0x1C, %
  soc_kw:
    - sensor.solax_*_battery_soc_kwh           # template: soc% * capacity_kWh / 100
  battery_power:
    - sensor.solax_*_battery_power_charge      # W, negative = discharge
  battery_power_invert:
    - true
    - true
  pv_power:
    - sensor.solax_*_pv_power_total
  battery_voltage:
    - sensor.solax_*_battery_voltage_charge    # for W->A conversion
  timed_charge_current:
    - number.solax_*_battery_charge_max_current  # reg 0x24, 0-50A
  timed_discharge_current:
    - number.solax_*_battery_discharge_max_current # reg 0x25, 0-50A
  charge_start_time:
    - time.solax_*_charge_start_1              # reg 0x92
  charge_end_time:
    - time.solax_*_charge_end_1                # reg 0x94
  discharge_start_time:
    - time.solax_*_discharge_start_1           # reg 0x96
  discharge_end_time:
    - time.solax_*_discharge_end_1             # reg 0x98

Notes

• num_inverters: 2 is required for dual-inverter setups
• The charger_use_mode select has 3 options: "Self Use Mode" (0), "Force Time Use" (1), "Back Up Mode" (2)
• Gen2 does NOT have manual_mode_select (Force Charge / Force Discharge) — introduced in Gen4
• Battery voltage is needed for PredBat W->A conversion (nominal ~52V for Pylontech US3000)
• The battery_charge_max_current register has scale=0.01 for Gen2 (vs scale=0.1 for Gen3+)
• Both inverters share the same definition; entity IDs differ by inverter suffix

[MJP-76]

Update: Working configuration with key findings

After extensive testing, here are important details for implementing SX2 support:

Required Config Items

1. num_inverters: 2 is required for dual-inverter setups. Without this, PredBat defaults to 1 and only sees Inverter 0.

2. soc_kw is needed alongside soc_percent. The battery curve calculation requires both sensors:

   soc_percent:
     - sensor.solax_*_battery_capacity          # reg 0x1C, %
   soc_kw:
     - sensor.solax_*_battery_soc_kwh           # template: soc% * capacity_kWh / 100

3. battery_rate_max must be set to ~2400W per inverter (not 2600W). The Gen2 battery_charge_max_current register has a 50A hardware limit, and 2600W / 48V = 54.1A which exceeds it.

4. load_power must be a list when num_inverters > 1, even if both entries point to the same sensor:

   load_power:
     - "sensor.total_house_load"
     - "sensor.total_house_load"

Balancing Notes

• balance_inverters_charge: false is recommended — with charge balancing enabled, the high-SoC inverter has its charge rate reduced to 0 during force charge, preventing both inverters from charging at full power.
• balance_inverters_crosscharge: false prevents one inverter from charging the other battery.
• balance_inverters_discharge: true works correctly — higher-SoC inverter discharges more, lower-SoC discharges less, proportional to battery size.

Control Model Details

• The charger_use_mode select has 3 options: "Self Use Mode" (0), "Force Time Use" (1), "Back Up Mode" (2)
• Timed charging is enabled by switching to "Force Time Use" mode + setting time windows
• No "Force Charge" select exists on Gen2 (that is a Gen4+ feature via manual_mode_select)
• Charge/discharge current is controlled via number.solax_*_battery_charge_max_current / battery_discharge_max_current (0-50A, step 0.1)
• The battery_charge_max_current register has scale=0.01 for Gen2 (vs scale=0.1 for Gen3+)

Verified Working State

Both inverters now report correct SoC, power flow, and balancing works as expected. The custom SX2 definition is fully functional.

[gcoan]

thanks for sharing this

could you add the whole apps.yaml please so I can create a template from it

a few questions:

you've defined inverter type as SX2 but not used that as the name of the custom inverter definition

all of the predbat entity names, charge start time, end time,etc, I assume these need to be populated with the entity names of both inverters ?

in load_power, yes you will need two entries as you have two inverters, likewise pv_power, but if you have a combined total power sensor then you should set

load_power:
  - "sensor.total_house_load"
  - 0

otherwise you will double the load that predbat reads from the sensor

[MJP-76]

Thanks for the feedback — good point/tip on the double-counting.

I've been using PredBat for a while but used AI to clean up and restructure my apps.yaml yesterday for my two custom Gen2 inverter configs. AI doesn't always get it right — it doubled up load_power and grid_power as you predicted. Fixed now with 0 for the second entry.

My original config had only one line item on the load_power and grid_power which gave me an error that I needed two, but as it worked and was calculated correct I left it as was - now fixed

I also saw it snuck in the charge/discharge times which I did not use as the GEN2 is best controlled by changing the charge_mode - these have now been removed

A note on grid power: I use an IAMMETER energy meter (sensor.meter_power) for grid measurement, not the inverter CT clamps — the inverter CTs are slightly different and actually use the same CT clamp. Grid import/export power is derived from the IAMMETER's signed power reading (positive = import, negative = export).

Here's my working apps.yaml and template sensors for two Solax SK-SU5000e (Gen2 Hybrid) inverters with the SX2 custom definition:

apps.yaml

pred_bat:
  module: predbat
  class: PredBat

  ####################
  # BASICS
  ####################
  prefix: "predbat"
  timezone: "Europe/London"
  currency_symbols:
    - "£"
    - "p"
  template: false
  prediction_kernel_enable: true
  days_previous: 7
  forecast_hours: 48
  plan_random_delay: 0
  num_inverters: 2

  ####################
  # SOLCAST FORECAST (auto-discovered once installed)
  ####################

  ####################
  # OCTOPUS AGILE (direct from Octopus API)
  ####################
  rates_import_octopus_url: "https://api.octopus.energy/v1/products/AGILE-24-10-01/electricity-tariffs/E-1R-AGILE-24-10-01-B/standard-unit-rates"

  ####################
  # INVERTER TYPE - Solax Gen2 Hybrid (SK-SU5000e)
  ####################
  inverter_type:
    - SX2
    - SX2

  inverter_type:
    - SX2
    - SX2

  inverter:
    name: "SX2"
    has_rest_api: false
    has_mqtt_api: false
    has_service_api: false
    output_charge_control: "current"
    charge_control_immediate: false
    current_dp: 1
    charge_discharge_with_rate: false
    has_charge_enable_time: true
    has_discharge_enable_time: true
    has_target_soc: false
    target_soc_used_for_discharge: false
    has_reserve_soc: true
    has_timed_pause: false
    time_button_press: false
    support_charge_freeze: false
    support_discharge_freeze: false
    has_ge_inverter_mode: false
    has_fox_inverter_mode: false
    has_idle_time: false
    has_time_window: false
    charge_time_format: "HH:MM:SS"
    charge_time_entity_is_option: false
    can_span_midnight: true
    clock_time_format: "%H:%M:%S"
    num_load_entities: 1
    soc_units: "%"
    write_and_poll_sleep: 4


  ####################
  # GRID / LOAD (global sensors)
  ####################
  grid_power:
    - "sensor.grid_import_power"
    - 0
  grid_power_invert:
    - true
    - true
  load_power:
    - "sensor.total_house_load"
    - 0

  ####################
  # PER-INVERTER SENSORS
  ####################
  soc_percent:
    - "sensor.tock_solax1_battery_capacity"
    - "sensor.tock_solax2_battery_capacity"

  soc_kw:
    - "sensor.solax1_battery_soc_kwh"
    - "sensor.solax2_battery_soc_kwh"

  battery_power:
    - "sensor.tock_solax1_battery_power_charge"
    - "sensor.tock_solax2_battery_power_charge"
  battery_power_invert:
    - true
    - true

  pv_power:
    - "sensor.tock_solax1_pv_power_total"
    - "sensor.tock_solax2_pv_power_total"

  battery_voltage:
    - "sensor.tock_solax1_battery_voltage_charge"
    - "sensor.tock_solax2_battery_voltage_charge"

  battery_temperature:
    - "sensor.tock_solax1_battery_temperature"
    - "sensor.tock_solax2_battery_temperature"

  timed_charge_current:
    - "number.tock_solax1_battery_charge_max_current"
    - "number.tock_solax2_battery_charge_max_current"
  timed_discharge_current:
    - "number.tock_solax1_battery_discharge_max_current"
    - "number.tock_solax2_battery_discharge_max_current"

  charge_rate:
    - "number.tock_solax1_battery_charge_max_current"
    - "number.tock_solax2_battery_charge_max_current"
  discharge_rate:
    - "number.tock_solax1_battery_discharge_max_current"
    - "number.tock_solax2_battery_discharge_max_current"

  ####################
  # CHARGE/DISCHARGE ENABLE
  ####################
  scheduled_charge_enable:
    - "input_boolean.battery_force_charge_tock_solax1"
    - "input_boolean.battery_force_charge_tock_solax2"
  scheduled_discharge_enable:
    - "input_boolean.battery_force_charge_tock_solax1"
    - "input_boolean.battery_force_charge_tock_solax2"

  ####################
  # RESERVE & CAPACITY
  ####################
  reserve:
    - "input_number.battery_min_capacity"
    - "input_number.battery_min_capacity"
  soc_max:
    - 14.4
    - 10.5

  ####################
  # INVERTER LIMITS (W)
  ####################
  inverter_limit:
    - 5000
    - 5000
  battery_rate_max:
    - 2400
    - 2400

  ####################
  # ENERGY TRACKING
  ####################
  load_today: "sensor.daily_load_energy"
  import_today: "sensor.tock_daily_import"
  export_today: "sensor.tock_daily_export"
  pv_today: "sensor.tock_daily_solar_generation"

  ####################
  # SOLCAST PV FORECAST
  ####################
  pv_forecast_today: "sensor.solcast_pv_forecast_forecast_today"
  pv_forecast_tomorrow: "sensor.solcast_pv_forecast_forecast_tomorrow"
  days_previous_auto: true

  ####################
  # DUAL-INVERTER BALANCING
  ####################
  balance_inverters: true
  balance_inverters_crosscharge: false
  balance_inverters_threshold_charge: 2
  balance_inverters_threshold_discharge: 2
  freeze_export_during_demand: true

  ####################
  # STRATEGY (Octopus Agile)
  ####################
  metric_min_pv: 0.2
  metric_min_soc: 10
  metric_max_soc: 100
  charge_soc_limit: 100
  discharge_soc_limit: 10
  minimum_soc: 10
  reserve_soc: 10
  charge_power_limit: 3000
  discharge_power_limit: 3000

  mcp_enable: "True"

Template sensors:

These derive grid power, house load, daily energy, and battery SoC in kWh from the IAMMETER and Solax Modbus entities:

template sensors:
  - sensor:
      - name: "Grid Import Power"
        unique_id: grid_import_power
        state: >-
          {% set p = states('sensor.tock_meter_power') | float(0) %}
          {{ p if p > 0 else 0 }}
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement

      - name: "Grid Export Power"
        unique_id: grid_export_power
        state: >-
          {% set p = states('sensor.tock_meter_power') | float(0) %}
          {{ -p if p < 0 else 0 }}
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement

      - name: "Total House Load"
        unique_id: total_house_load
        state: >-
          {{ (states('sensor.tock_solax1_pv_power_total') | float(0)) + (states('sensor.tock_solax2_pv_power_total') | float(0)) + (states('sensor.tock_meter_power') | float(0)) }}
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement

      - name: "Daily Load Energy"
        unique_id: daily_load_energy
        state: >-
          {{ (states('sensor.tock_daily_import') | float(0)) + (states('sensor.tock_daily_solar_generation') | float(0)) - (states('sensor.tock_daily_export') | float(0)) }}
        unit_of_measurement: "kWh"
        device_class: energy
        state_class: total_increasing

      - name: "SolaX1 Battery SoC kWh"
        unique_id: solax1_battery_soc_kwh
        state: >-
          {{ (states('sensor.tock_solax1_battery_capacity') | float(0)) * 14.4 / 100 }}
        unit_of_measurement: "kWh"
        device_class: energy
        state_class: measurement

      - name: "SolaX2 Battery SoC kWh"
        unique_id: solax2_battery_soc_kwh
        state: >-
          {{ (states('sensor.tock_solax2_battery_capacity') | float(0)) * 10.5 / 100 }}
        unit_of_measurement: "kWh"
        device_class: energy
        state_class: measurement

Key Differences from Gen4 (SX4) - Updated as I go

Feature	Gen2 (SK-SU5000e)	Gen4 (SX4)
Charge control	Current (amps) via battery_charge_max_current (reg 0x24)	Power (W) via remote control
Remote control (Mode 8)	Not available	remotecontrol_power_control
manual_mode_select	Not available (Gen4+ only)	Force Charge / Force Discharge
charger_use_mode options	Self Use / Force Time Use / Back Up	+ Manual Mode, PeakShaving, Smart Schedule
Time windows	charge_start_1 (0x92), charge_end_1 (0x94), discharge_start_1 (0x96), discharge_end_1 (0x98)	Different register layout
Reserve SoC	battery_minimum_capacity (reg 0x20, 10-99%)	selfuse_discharge_min_soc
battery_charge_max_current scale	0.01 (Gen2)	0.1 (Gen3+)
Max current	50A hardware limit	Varies

[gcoan]

thanks for that, I've got some more comments and feedback for you

in your apps.yaml and templates I see you have created custom house load and load energy sensors, but you have missed out battery charge and discharge energy in the calculation

there is an example house load template sensor in the predbat documentation https://springfall2008.github.io/batpred/apps-yaml/#data-from-home-assistant that I wrote that takes into account battery charge/discharge, also handles if the underlying sensor isn't available, has a proper reset to 0 at midnight in case the underlying sensors don't perfectly align, and it updates every 5 minutes rather than every time the underlying sensors change value which reduces state history in the HA database

looks like you created some helpers, battery_min_capacity and battery_force_charge_tock_solaxX?

final comment is that your AI has hallucinated with a number of settings at the bottom of apps.yaml that are Home Assistant control entities that need to be set correctly, they are not things that go in apps.yaml.

Cheers

[MJP-76]

Again, Thanks for the input.

Am looking at your suggestions manually and advised my AI to the "read the docs"