Home-AssistantConfig/config/packages/battery_levels.yaml

#-------------------------------------------
#  Fire Tablet Alarm Panel -
#  https://www.vcloudinfo.com/2017/07/visualizing-smart-home-using-home.html
#-------------------------------------------
#
# homeassistant:
#   customize_glob:
#     "sensor.*_alarm_panel*":
#
#
#     "binary_sensor.*_alarm_panel*":
#
#

sensor:
  - platform: template
    sensors:
      low_battery:
        friendly_name: 'Low Battery'
        entity_id: []
        value_template: >
          {%- set threshold = 15 -%}
          {%- set domains = ['light', 'switch', 'sensor', 'zwave', 'lock', 'binary_sensor'] -%}
          {%- for domain in domains -%}
            {%- for item in states[domain] if ((item.attributes.battery_level is defined and item.attributes['battery_level'] | int < threshold) or ("battery" in item.name | lower and ((item.state | int < threshold and item.state|int != 0) or item.state | lower == "low" or item.state | lower == "unknown"))) -%}
              {{ item.attributes.friendly_name }} (
              {%- if item.attributes.battery_level is defined -%}
                {{ item.attributes.battery_level}}
              {%- else -%}
                {{item.state}}
              {%- endif -%}%)
              {%- if not loop.last -%}
                {{', '}}
              {%- endif -%}
            {%- endfor -%}
          {%- endfor -%}

automation:
  - alias: 'Battery Alert'
    initial_state: 'on'
    trigger:
      - platform: time
        at: '10:00:00'
      - platform: time
        at: '18:00:00'
    condition:
      condition: template
      value_template: "{% if states('sensor.low_battery') %}true{% endif %}"
    action:
      - service: persistent_notification.create
        data_template:
          title: Low Battery
          message: "{{ states('sensor.low_battery') }}"
          notification_id: low-battery-alert
      - service: script.notify_engine
        data_template:
          value1: "Low battery levels: {{ states('sensor.low_battery') }}"
          who: 'carlo'
          apns_id: 'information'