Great Tip from @gabrielemariotti to clean up Template Sensors across the board. #529

config/packages/battery_levels.yaml

@@ -17,6 +17,7 @@ sensor:
     sensors:
       low_battery:
         friendly_name: 'Low Battery'
+        entity_id: []
         value_template: >
           {%- set threshold = 15 -%}
           {%- set domains = ['light', 'switch', 'sensor', 'zwave', 'lock', 'binary_sensor'] -%}