Fix 0.0 check on battery percentage template (#4404)

Author: andrew-codechimp

custom_components/battery_notes/common.py

@@ -8,7 +8,7 @@
 
 def validate_is_float(num):
     """Validate value is a float."""
-    if num:
+    if num is not None:
         try:
             float(num)
             return True

custom_components/battery_notes/coordinator.py

@@ -608,6 +608,8 @@ def current_battery_level(self, value):
             self._previous_battery_low = self.battery_low
             self._previous_battery_level = self._current_battery_level
 
+        self.async_set_updated_data(None)
+
     @property
     def battery_type_and_quantity(self) -> str:
         """Merge battery type & quantity."""
@@ -729,7 +731,9 @@ def battery_low(self) -> bool:
         if self.battery_low_template:
             return self.battery_low_template_state
         elif self.battery_percentage_template or self.wrapped_battery:
-            if validate_is_float(self.current_battery_level):
+            if self.current_battery_level is not None and validate_is_float(
+                self.current_battery_level
+            ):
                 return bool(
                     float(self.current_battery_level) < self.battery_low_threshold
                 )