Estimation of electric car consumption (E.g. Renault Zoe)

Configuration
1

Hello,
I have a Renault Zoe (electric car).
The garage where I park/charge the car doesn’t allow to receive “cells phone” : thus the car cannot communicate its state (in particular “in charge” or “not in charge”).
My idea to estimate the consumption is to consider my remaining battery state : if it increase (with a threshold) it means that I have charged the car. (by knowing the capacity of my car, I can estimate the charge I’ve made)
Any idea how to perform this computation ? Does any has create a sensor for this ? or to put together several integrations (I need something that give the previous state : after it’s straight forward with a sensor template)
Thanks in advance
Philippe

2

Here a solution based on SQL.
Please note, the idea is to compute the difference between current battery value and former one .
Then you can evaluate when you charge (the battery value increase) thanks to the capacity of the car (e.g. My Zoe is 41kWh)

Let’s assumed that sensor.battery_level is the current battery value (in %)
In configuration.yaml, you can declare :

  1. the current value not needed, just to understand 
  - platform: sql
    db_url: !secret database_url
    queries:
      - name: last_battery_level
        query: "SELECT * FROM states WHERE entity_id = 'sensor.battery_level' ORDER BY state_id DESC LIMIT 1;"
        column: "state"
        unit_of_measurement: '%'
  1. the former value not needed, just to understand 
  - platform: sql
    db_url: !secret database_url
    queries:
      - name: before_last_battery_level
        query: "SELECT * FROM (SELECT * FROM states WHERE entity_id = 'sensor.battery_level' ORDER BY state_id DESC LIMIT 2) two_entity  ORDER BY state_id ASC LIMIT 1;"
        column: "state"
        unit_of_measurement: '%'
  1. the difference between current and former battery value (NEEDED)
  - platform: sql
    db_url: !secret database_url
    queries:
      - name: diff_last_and_before_last_battery_level
        query: "SELECT SUM(state) AS query_result FROM
                (
                   (SELECT state FROM states WHERE entity_id = 'sensor.battery_level' ORDER BY state_id DESC LIMIT 1)
                   UNION ALL
                   (
                      SELECT (-1*state) FROM
                      (
                        SELECT * FROM states WHERE entity_id = 'sensor.battery_level' ORDER BY state_id DESC LIMIT 2
                      ) two_entity  ORDER BY state_id ASC LIMIT 1
                   )
                ) last_battery_levels
               ;"
        column: "query_result"
        unit_of_measurement: '%'
  1. Then based on battery capacity of your car (e.g. 41kWh) , you can evaluate the charge you perform :
  - platform: template
    sensors:
      charge_battery_level_sql:
        unit_of_measurement: 'kWh'
        value_template: >-
           {% if ((states('sensor.diff_last_and_before_last_battery_level') | float) < 0 ) %}
              0
           {% else %}
              {{ (states('sensor.diff_last_and_before_last_battery_level') | float) * 41 / 100  }}
           {% endif %}

Hope it can help

3

Hello,
In order to have a robust sensor, and a simplier way, I have written a custom_component :
https://github.com/jugla/battery_consumption

4

Hi,
unfortunately your solution GitHub - jugla/battery_consumption: Home Assistant Component to compute battery consumption is not working for me. I could create the folder battery_consumption in custom_components and added the code as described into configuration.yaml.
The error message I receive is that the new created sensor zoe_batterie_total_discharge has no unique ID. (…total_charge as well)
Maybe this is related to the new created sensor battery_level+name of sensor to monitor, because its not really clear how to combine it in the code.
Any idea, what could have happened? Thanks,
Holger

5

Hello,
Please can you cut and paste, the corresponding part of configuration.yaml.
Thanks