Template sensor:🔋 Battery charging time to full and discharging time to empty

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Hi! I am using the HACS integration battery_sim to simulate a “Works locally with Home Assistant”-home battery I pre-ordered. Because of this, I have sensors indicating the current capacity in kWh and the current charging and discharging rates in kW.

I wanted to have a sensor that’ll estimate the time to a complete (dis)charge. I couldn’t find any examples on the internet so I decided to make my own and publish it here!

How to reproduce

  • Go to Settings > Devices & Services > Helpers > Create Helper > Template > Template Sensor.
  • Enter any name you want, e.g. “HWE Battery - time to full”.
  • Enter the templates provided below and replace the sensor entities with your own.
  • Set the Device Class to ‘Timestamp’ and leave the other options empty.
  • Done!

:battery: Template to estimate when a battery is full:

  • Replace sensor.battery_sim_hwe_current_charging_rate with your current charging speed in kW.
  • Replace sensor.battery_sim_hwe with your current charge level in kWh.
  • Set full_capacity to the full battery capacity in kWh.
{% if states('sensor.battery_sim_hwe_current_charging_rate') | float > 0 %}
  {% set full_capacity = 2.688 | float %}
  {% set remaining_capacity = full_capacity - states('sensor.battery_sim_hwe') | float %}
  {% set charging_time_seconds = (remaining_capacity / states('sensor.battery_sim_hwe_current_charging_rate') | float) * 3600 %}
  {{ now() + timedelta(seconds=charging_time_seconds) }}
{% endif %}

:low_battery: Template to estimate when a battery is empty:

  • Replace sensor.battery_sim_hwe_current_discharging_rate with your current discharging speed in kW.
  • Replace sensor.battery_sim_hwe with your current charge level in kWh.
{% if states('sensor.battery_sim_hwe_current_discharging_rate') | float > 0 %}
  {% set remaining_capacity = states('sensor.battery_sim_hwe') | float %}
  {% set discharging_time_seconds = (remaining_capacity / states('sensor.battery_sim_hwe_current_discharging_rate') | float) * 3600 %}
  {{ now() + timedelta(seconds=discharging_time_seconds) }}
{% endif %}

They’ll look like this: (state will be ‘Unknown’ when there is no estimate to be made, obviously)

image
image695×188 9.4 KB

Enjoy, and be sure to let me know if and how you used it or if you improved on it!

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