home-assistant.io/source/_cookbook/track_battery_level.markdown

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layout	title	description	date	sidebar	comments	sharing	footer	ha_category
page	Track your battery level	Basic example how to track the battery level of your mobile devices.	2016-01-29 09:00	true	false	true	true	Automation Examples

{% linkable_title iOS Devices %}

If you have a device running iOS (iPhone, iPad, etc), The iCloud is gathering various details about your device including the battery level. To display it in the Frontend use a template sensor. You can also use the icon template option to create a dynamic icon that changes with the battery level.

{% raw %}

sensor:
  - platform: template
    sensors:
      battery_iphone:
        friendly_name: iPhone Battery
        # "entity_id:" ensures that this sensor will only update when your device tracker does.
        entity_id: device_tracker.iphone
        unit_of_measurement: '%'
        value_template: >-
            {%- if states.device_tracker.iphone.attributes.battery %}
                {{ states.device_tracker.iphone.attributes.battery|round }}
            {% else %}
                {{ states.sensor.battery_iphone.state }}
            {%- endif %}
        icon_template: >
            {% set battery_level = states.sensor.battery_iphone.state|default(0)|int %}
            {% set battery_round = (battery_level / 10) |int * 10 %}
            {% if battery_round >= 100 %}
              mdi:battery
            {% elif battery_round > 0 %}
              mdi:battery-{{ battery_round }}
            {% else %}
              mdi:battery-alert
            {% endif %}

{% endraw %}

The else part is used to have the sensor keep its last state if the newest iCloud update doesn't have any battery state in it (which happens sometimes). Otherwise the sensor will be blank.

{% linkable_title Android and iOS Devices %}

While running the Owntracks device tracker you can retrieve the battery level with a MQTT sensor. Replace username with your MQTT username (for the embedded MQTT it's simply homeassistant), and deviceid with the set Device ID in Owntracks.

{% raw %}

sensor:
  - platform: mqtt
    state_topic: "owntracks/username/deviceid"
    name: "Battery Tablet"
    unit_of_measurement: "%"
    value_template: '{{ value_json.batt }}'

{% endraw %}