Added slot boundary check back in

custom_components/ohme/binary_sensor.py

@@ -101,6 +101,7 @@ def __init__(
 
         # Cache the last power readings
         self._last_reading = None
+        self._last_reading_in_slot = False
 
         self.entity_id = generate_entity_id(
             "binary_sensor.{}", "ohme_car_charging", hass=hass)
@@ -126,15 +127,33 @@ def _calculate_state(self) -> bool:
         """Some trickery to get the charge state to update quickly."""
         power = self.coordinator.data["power"]["watt"]
 
-        # If no last reading or no batterySoc, fallback to power > 0
-        if not self._last_reading or not self._last_reading['batterySoc']:
+        # If no last reading or no batterySoc/power, fallback to power > 0
+        if not self._last_reading or not self._last_reading['batterySoc'] or not self._last_reading['power']:
             return power > 0
 
-        # If Wh has positive delta and a nonzero power reading, we are charging
+        # See if we are in a charge slot now and if we were for the last reading
+        in_charge_slot = charge_graph_in_slot(
+            self.coordinator.data['startTime'], self.coordinator.data['chargeGraph']['points'])
+        lr_in_charge_slot = self._last_reading_in_slot
+        lr_power = self._last_reading["power"]["watt"]
+        # Store this for next time
+        self._last_reading_in_slot = in_charge_slot
+
+        # If:
+        # - Power has dropped by 40% since the last reading
+        # - Last reading we were in a charge slot
+        # - Now we are not in a charge slot
+        # The charge has stopped but the power reading is lagging.
+        # This condition makes sure we get the charge state updated on the tick immediately after charge stop.
+        if lr_power > 0 and power / lr_power < 0.6 and not in_charge_slot and lr_in_charge_slot:
+            return False
+
+        # Failing that, we use the watt hours field to check charge state:
+        # - If Wh has positive delta and a nonzero power reading, we are charging
         # This isn't ideal - eg. quirk of MG ZS in #13, so need to revisit
-        delta = self.coordinator.data['batterySoc']['wh'] - self._last_reading['batterySoc']['wh']
+        wh_delta = self.coordinator.data['batterySoc']['wh'] - self._last_reading['batterySoc']['wh']
 
-        return delta > 0 and power > 0
+        return wh_delta > 0 and power > 0
 
     @callback
     def _handle_coordinator_update(self) -> None: