JSON String read out an configure to sensor

  - name: Cell_0
    state_topic: "Jsn"
    unit_of_measurement: "mV"
    value_template: "{{ value_json.bat.0 }}"

  - name: Cell_1
    state_topic: "Jsn"
    unit_of_measurement: "mV"
    value_template: "{{ value_json.bat.1 }}"