{
  services.home-assistant.config = {
    sensor = [
      {
        platform = "template";
        sensors = {
          sensors_lowest_battery_level = {
            friendly_name = "Lowest battery level (Sensors)";
            entity_id = "sun.sun";
            device_class = "battery";
            unit_of_measurement = "%";
            value_template = ''
              {% set domains = ['sensor', 'battery'] %}
              {% set ns = namespace(min_batt=100, entities=[]) %}
              {%- set exclude_sensors = ['sensor.sensors_lowest_battery_level','sensor.dominiks_iphone_battery_level'] -%}
              {% for domain in domains %}
                {% set ns.entities = states[domain] %}
                {% for sensor in exclude_sensors %}
                  {% set ns.entities = ns.entities | rejectattr('entity_id', 'equalto', sensor) %}
                {% endfor %}
                {% set batt_sensors = ns.entities | selectattr('attributes.device_class','equalto','battery') | map(attribute='state') | reject('equalto', 'unknown') | reject('equalto', 'None') | map('int') | reject('equalto', 0) | list %}
                {% set batt_attrs = ns.entities | selectattr('attributes.battery_level','defined') | map(attribute='attributes.battery_level') | reject('equalto', 'unknown') | reject('equalto', 'None') | map('int') | reject('equalto', 0) | list %}
                {% set batt_lvls = batt_sensors + batt_attrs %}
                {% if batt_lvls|length > 0 %}
                  {% set _min = batt_lvls|min %}
                  {% if _min < ns.min_batt %}
                    {% set ns.min_batt = _min %}
                  {% endif %}
                {% endif %}
              {% endfor %}
              {{ ns.min_batt }}         
            '';
          };
        };
      }
    ];
    binary_sensor = [
      {
        platform = "template";
        sensors = {
          sensor_low_battery = {
            value_template = "{{ states('sensor.sensors_lowest_battery_level')|int <= 30 }}";
            friendly_name = "A sensor has low battery";
            device_class = "problem";
          };
        };
      }
    ];
    alert = {
      sensor_low_battery = {
        name = "Sensor has low battery!";
        message = ''
          {% set domains = ['sensor', 'battery'] %}
          {% set threshold = 30 %}
          {%- set exclude_entities = ['sensor.sensors_lowest_battery_level','sensor.dominiks_iphone_battery_level','sensor.roborock_s8_pro_ultra_battery'] -%}
          Sensors are below 50% battery:
          {% for domain in domains %}
            {% for item in states[domain] %}
              {% if item.entity_id not in exclude_entities %}
                {% if item.attributes.battery_level is defined %}
                  {% set level = item.attributes.battery_level|int %}
                  {% if level > 0 and level < threshold %}
          - {{ item.attributes.friendly_name }} ({{ item.attributes['battery_level']|int}}%)
                  {%- endif -%}
                {% endif %}
                {% if item.attributes.device_class is defined and item.attributes.device_class == 'battery' %}
                  {% set level = item.state|int %}
                  {% if level > 0 and level <= threshold %}
          - {{ item.attributes.friendly_name }} ({{ item.state|int }}%)
                  {% endif %}
                {% endif %}
              {% endif %}
            {% endfor %}
          {% endfor %}      
        '';
        entity_id = "binary_sensor.sensor_low_battery";
        state = "on";
        repeat = [
          5
          60
          360
        ];
        skip_first = true;
        can_acknowledge = true;
        notifiers = [
          "NotificationGroup"
        ];
      };
    };
  };
}