Car charging planning

You will firstly need to configure the Car charging settings in apps.yaml and have installed the appropriate Home Assistant integration for your car charger. As a bare minimum a HA-controllable smart plug with a granny charger could be used, but do consider there could be an electrical spike to the car if the smart plug is turned off when the car is charging. A proper car charger and HA integration is preferable.

There are two ways that Predbat can plan the slots for charging your car:

If you have Intelligent Octopus import tariff, have completed enrollment of your car/charger to Intelligent Octopus (requires a compatible charger or car), and you have installed the Octopus Energy integration - in which case Predbat will use the car charging slots allocated by Octopus Energy in battery prediction. The Octopus Energy integration supports Octopus Intelligent, and through that Predbat gets most of the information it needs.
- octopus_intelligent_slot in apps.yaml is pre-configured with a regular expression to point to the Intelligent Slot sensor in the Octopus Energy integration. You should not need to change this, but its worth checking the Predbat logfile to confirm that it has found your Octopus account details
- Set switch.predbat_octopus_intelligent_charging to True
- Information about the car's battery size will be automatically extracted from the Octopus Energy integration
- You should set the cars current soc sensor, car_charging_soc in apps.yaml to point to a Home Assistant sensor that specifies the car's current % charge level to have accurate results. This should normally be a sensor provided by your car charger. If you don't have this available for your charger then Predbat will assume the car's current charge level is 0%.
- If you set car_charging_limit in apps.yaml then Predbat can also know if the car's limit is set lower than in Intelligent Octopus. If you don't set this Predbat will default to 100%.
- You can use car_charging_now as a workaround to indicate your car is charging but the Intelligent API hasn't reported it.
- Let the Octopus app control when your car charges.
Predbat-led charging - Here Predbat plans and can initiate the car charging based on the upcoming low rate slots
- Ensure car_charging_limit, car_charging_soc and car_charging_planned are set correctly in apps.yaml.
- Set select.predbat_car_charging_plan_time in Home Assistant to the time you want the car to be ready by.
- Enable switch.predbat_car_charging_plan_smart if you want to use the cheapest slots only.
- You can set car_charging_plan_max_price if you want to set a maximum price per kWh to charge your car (e.g. 10p) If you leave this disabled then all low rate slots will be used. This may mean you need to use expert mode and change your low rate threshold to configure which slots should be considered if you have a tariff with more than 2 import rates (e.g. flux)
- Predbat will set binary_sensor.predbat_car_charging_slot when it determines the car can be charged; you will need to write a Home Assistant automation based on this sensor to control when your car charges.
  A sample automation to start/stop car charging using a Zappi car charger and the MyEnergi Zappi integration is as follows, this should be adapted for your own charger type and how it controls starting/stopping car charging:
yaml alias: Car charging description: "Start/stop car charging based on Predbat determined slots" trigger: - platform: state entity_id: - binary_sensor.predbat_car_charging_slot action: - choose: - conditions: - condition: state entity_id: binary_sensor.predbat_car_charging_slot state: "on" sequence: <commands to turn on your car charger, e.g.> - service: select.select_option data: option: Eco+ target: entity_id: select.myenergi_zappi_charge_mode - conditions: - condition: state entity_id: binary_sensor.predbat_car_charging_slot state: "off" sequence: <commands to turn off your car charger, e.g.> - service: select.select_option data: option: Stopped target: entity_id: select.myenergi_zappi_charge_mode mode: single
- WARNING: Do not set car_charging_now or you will create a circular dependency.

NOTE: Multiple cars can be planned with Predbat.

See Car charging filtering and Planned car charging in the apps.yaml settings section of the documentation.

Example EV and charger setup and Predbat automation to use the cheapest charging slots with no/limited Home Assistant Integration

MG4 EV Vehicle with a Hypervolt Car Charger. There is no 3rd party integration with the MG, and the Hypervolt car charger doesn't understand when an EV is plugged in.

Yet it can be stopped and started with a 3rd party integration.

In Home Assistant, create two helper entities (Settings / Devices & Services / Helpers) of type 'Number':

EV Max Charge - input_number.car_max_charge
EV Current SOC in kWh - input_number.predbat_car_charging_manual_soc_kwh

Create a 'Dropdown' helper entity that has two options 'true' and 'false' (in lower case):

Car Charger Plugged in - input_select.car_charger_plugged_in

Within the apps.yaml configuration file specify the following configuration settings:

Find the line for car_charger_battery_size and enter the Car Battery Size in kWh:

Example

  car_charging_battery_size:
    - 61.7

Specify the Car Charging Limit to use the EV Max Charge helper entity created earlier:

  car_charging_limit:
    - 're:(input_number.car_max_charge)'

Find car_charging_planned and add the input_select.car_charger_plugged_in dropdown helper entity to the end of the line:

  car_charging_planned:
    - 're:(sensor.wallbox_portal_status_description|sensor.myenergi_zappi_[0-9a-z]+_plug_status|input_select.car_charger_plugged_in)'

Find car_charging_planned_response and add 'true' to the list:

  car_charging_planned_response:
    - 'yes'
    - 'on'
    - 'true'

If possible, add an entity keeping track of the kWh used for car charging to car_charging_energy.

If your charging device doesn't keep track of kWh but you can measure the power sent to the car charger (e.g. from the EV charger integration or an energy monitor/smart plug for the EV charger) then you can create another helper entity to convert kW power into kWh:

Create a helper entity (Settings / Devices & Services / Helpers) of type 'Integration - Riemann Sum integral':

Name : car_energy_used
Input sensor : sensor that measures power consumed by the car charger
Integration method : Right Riemann sum
Metric prefix : k (kilo)

Please look into Integration - Riemann sum integral to convert kW into kWh.

Example

car_charging_energy: 're:(sensor.myenergi_zappi_[0-9a-z]+_charge_added_session|sensor.wallbox_portal_added_energy|sensor.car_energy_used)'

car_charging_now must be commented out (hashed out) in apps.yaml:

  #car_charging_now:
  #  - off

Save the apps.yaml file and exit.

In Home Assistant, turn on the following Predbat control switches:

switch.predbat_car_charging_hold
switch.predbat_car_charging_manual_soc
switch.predbat_car_charging_plan_smart

And turn off the Predbat control switch:

switch.predbat_octopus_intelligent_charging

HA Charging Slot Automation

In Home Assistant (Settings / Automation & Scenes), create an automation to monitor the Predbat car charging slot sensor and turn the charger on and off according to the Predbat plan:

alias: Car Charging Slot
description: ""
trigger:
  - platform: state
    entity_id:
      - binary_sensor.predbat_car_charging_slot
action:
  - if:
      - condition: state
        entity_id: binary_sensor.predbat_car_charging_slot
        state: "off"
    then:
      - type: turn_off
        device_id: ac8b06952c7fe838314e
        entity_id: f6de2df0758744aba60f6b5f
        domain: switch
  - if:
      - condition: state
        entity_id: binary_sensor.predbat_car_charging_slot
        state: "on"
    then:
      - type: turn_on
        device_id: ac8b06952c7fe838314e
        entity_id: f6de2df0758744aba60f6b5f
        domain: switch
mode: single

Finally, for simplicity, add the below entities to your HA Dashboard:

EV Max Charge - input_number.car_max_charge
EV Current SOC in kWh - input_number.predbat_car_charging_manual_soc_kwh
Car Charger Plugged in - input_select.car_charger_plugged_in

Annoyingly, you have to calculate the kWh your vehicle has in total by taking the Percentage left in the car / 100 * Total EV Battery capacity.
For example:

65/100*61.7=40.1

Enter '40.1' into 'EV Current SOC in kWh' and '80%' into 'EV Max charge'.

Once the charger is switched to true and your EV Max charge (target SOC) % is higher than the kWh currently in the car, Predbat will plan and charge the EV with the kW that are needed to reach the EV target SOC.