Home Assistant Blueprint: Low battery level detection & notification for all battery sensors based on https://community.home-assistant.io/t/plant-moisture-notification/369425

home-assistant_plant-moisture-notification.yaml

blueprint:
  name: Low moisture level detection & notification for all plant sensors
  description: Regularly test all plant sensors with 'moisture' crossing
    under their threshold.
  domain: automation
  input:
    threshold:
      name: Water warning level threshold
      description: Water sensors below threshold are assumed to be low-Water (as
        well as binary battery sensors with value 'on').
      default: 20
      selector:
        number:
          min: 5.0
          max: 100.0
          unit_of_measurement: '%'
          mode: slider
          step: 5.0
    time:
      name: Time to test on
      description: Test is run at configured time
      default: '10:00:00'
      selector:
        time: {}
    day:
      name: Weekday to test on
      description: 'Test is run at configured time either everyday (0) or on a given
        weekday (1: Monday ... 7: Sunday)'
      default: 0
      selector:
        number:
          min: 0.0
          max: 7.0
          mode: slider
          step: 1.0
    exclude:
      name: Excluded Sensors
      description: Plant sensors (e.g. cactus) to exclude from detection. Only entities are supported, devices must be expanded!
      default: {entity_id: []}
      selector:
        target:
          entity:
            domain: plant
    actions:
      name: Actions
      description: Notifications or similar to be run. {{sensors}} is replaced with
        the names of sensors being low on battery.
      selector:
        action: {}
variables:
  day: !input 'day'
  threshold: !input 'threshold'
  exclude: !input 'exclude'
  sensors: >-
    {% set result = namespace(sensors=[]) %}
    {% for state in states.plant if 'moisture low' in state.attributes.problem %}
      {% if not state.entity_id in exclude.entity_id %}
        {% set result.sensors = result.sensors + [state.attributes.friendly_name] %}
      {% endif %}
    {% endfor %}
    {{result.sensors|join(', ')}}
trigger:
- platform: time
  at: !input 'time'
condition:
- '{{ sensors != '''' and (day | int == 0 or day | int == now().isoweekday()) }}'
action:
- choose: []
  default: !input 'actions'
mode: single