Questions to battery notes

Third party integrations
1

Heyho
Ive started using battery notes and custom battery state card.
On my dashboard I want to have an overview of devices with battery less than 20%.
Ive done this with the following card:

type: custom:battery-state-card
colors:
  steps:
    - "#ff0000"
    - "#ffff00"
    - "#00ff00"
  gradient: true
secondary_info: "{attributes.battery_type_and_quantity}"
round: 0
filter:
  include:
    - name: entity_id
      value: "*_battery_plus"
  exclude:
    - name: state
      value: 20
      operator: ">"
    - name: state
      value: 0
      operator: <
bulk_rename:
  - from: Batterie+
sort:
  - state
  - name
collapse: 10

But if I have no devices with battery below 20 I will see an empty card.
Is there a way to add a condition to make this card invisible if there is no device?

And second question is the battery_notes action: check_battery_low
The integrtions documentation sais I can use this in combination with another automtion to perform a daily “low bttery ckeck”. But how do I do this?
If I call this check battery low action nothing happens (I dont see anythin atleast).

2

Create a boolean with the condition if there are any batteries less than 20% and use this boolean in the conditional card to hide the card if none is less than 20%