diff --git a/src/vehicle.py b/src/vehicle.py
index 624c123d..68c94adb 100644
--- a/src/vehicle.py
+++ b/src/vehicle.py
@@ -118,7 +118,8 @@ def __init__(
         # treat high voltage battery as active, if we don't have any other information
         self.__hv_battery_active = True
         self.__hv_battery_active_from_car = True
-        self.is_charging = False
+        self.__is_charging = False
+        self.__had_significant_charging_power = False
         self.refresh_period_active = -1
         self.refresh_period_inactive = -1
         self.refresh_period_after_shutdown = -1
@@ -285,6 +286,24 @@ def is_complete(self) -> bool:
             and self.refresh_mode is not None
         )
 
+    @property
+    def is_charging(self) -> bool:
+        return self.__is_charging
+
+    @is_charging.setter
+    def is_charging(self, new_state: bool) -> None:
+        old_state = self.__is_charging
+        if old_state and not new_state and self.__had_significant_charging_power:
+            self.last_car_shutdown = datetime.datetime.now(tz=datetime.UTC)
+            LOG.info(
+                "Charging stopped for vehicle %s, resetting last_car_shutdown to %s",
+                self.vin,
+                self.last_car_shutdown,
+            )
+        if not new_state:
+            self.__had_significant_charging_power = False
+        self.__is_charging = new_state
+
     def set_is_charging(self, is_charging: bool) -> None:
         self.is_charging = is_charging
         self.hv_battery_active = self.is_charging
@@ -578,6 +597,8 @@ def handle_charge_status(
         self.is_charging = result.is_charging or False
 
         if self.is_charging and result.power is not None and result.power < -1:
+            # Mark that we've seen significant charging power (> 1kW)
+            self.__had_significant_charging_power = True
             # Only compute a dynamic refresh period if we have detected at least 1kW of power during charging
             time_for_1pct = (
                 36.0 * result.real_total_battery_capacity / abs(result.power)
@@ -599,11 +620,11 @@ def handle_charge_status(
         elif not self.is_charging:
             # Reset the charging refresh period if we detected we are no longer charging
             self.set_refresh_period_charging(0)
-        else:
-            # Otherwise let's keep the last computed refresh period
-            # This avoids falling back to the active refresh period which, being too often, results in a ban from
-            # the SAIC API
-            pass
+        elif self.refresh_period_charging < self.refresh_period_after_shutdown:
+            # Charging with insignificant power (< 1kW, e.g. OBC trickle/maintenance).
+            # Use at least the after-shutdown period to avoid polling at the active rate (30s)
+            # indefinitely, which wastes API quota and can drain the 12V battery.
+            self.set_refresh_period_charging(self.refresh_period_after_shutdown)
 
         return result
 
diff --git a/tests/test_vehicle_state.py b/tests/test_vehicle_state.py
index d02eb669..fce1a611 100644
--- a/tests/test_vehicle_state.py
+++ b/tests/test_vehicle_state.py
@@ -20,7 +20,7 @@
 from configuration import Configuration
 from exceptions import VehicleStatusDriftException
 import mqtt_topics
-from vehicle import RefreshMode, VehicleState
+from vehicle import PollingPhase, RefreshMode, VehicleState
 from vehicle_info import VehicleInfo
 
 from .common_mocks import (
@@ -336,6 +336,156 @@ def test_mileage_of_day_published_when_no_vehicle_status_yet(self) -> None:
             DRIVETRAIN_MILEAGE_OF_DAY,
         )
 
+    def test_is_charging_true_to_false_resets_last_car_shutdown(self) -> None:
+        """When is_charging transitions True -> False after significant power, last_car_shutdown is updated."""
+        old_shutdown = self.vehicle_state.last_car_shutdown
+        self.vehicle_state.is_charging = True
+        # Simulate significant charging power detected via handle_charge_status
+        self.vehicle_state._VehicleState__had_significant_charging_power = True
+        self.vehicle_state.is_charging = False
+        assert self.vehicle_state.last_car_shutdown > old_shutdown
+
+    def test_is_charging_true_to_false_without_significant_power_does_not_reset(
+        self,
+    ) -> None:
+        """When is_charging transitions True -> False without significant power, no reset."""
+        old_shutdown = self.vehicle_state.last_car_shutdown
+        self.vehicle_state.is_charging = True
+        # No significant power flag set (e.g. OBC trickle)
+        self.vehicle_state.is_charging = False
+        assert self.vehicle_state.last_car_shutdown == old_shutdown
+
+    def test_is_charging_false_to_false_does_not_reset_last_car_shutdown(self) -> None:
+        """When is_charging stays False, last_car_shutdown is not updated."""
+        old_shutdown = self.vehicle_state.last_car_shutdown
+        self.vehicle_state.is_charging = False
+        assert self.vehicle_state.last_car_shutdown == old_shutdown
+
+    def test_is_charging_true_to_true_does_not_reset_last_car_shutdown(self) -> None:
+        """When is_charging stays True, last_car_shutdown is not updated."""
+        self.vehicle_state.is_charging = True
+        old_shutdown = self.vehicle_state.last_car_shutdown
+        self.vehicle_state.is_charging = True
+        assert self.vehicle_state.last_car_shutdown == old_shutdown
+
+    def test_should_refresh_off_publishes_off_phase(self) -> None:
+        self.vehicle_state.configure_missing()
+        self.vehicle_state.set_refresh_mode(RefreshMode.OFF, "test")
+        self.publisher.map.clear()
+        result = self.vehicle_state.should_refresh()
+        assert result is False
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.OFF.value,
+        )
+
+    def test_should_refresh_force_publishes_force_phase(self) -> None:
+        self.vehicle_state.configure_missing()
+        self.vehicle_state.set_refresh_mode(RefreshMode.FORCE, "test")
+        self.publisher.map.clear()
+        result = self.vehicle_state.should_refresh()
+        assert result is True
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.FORCE.value,
+        )
+
+    def test_should_refresh_charging_detection_resets_shutdown(self) -> None:
+        self.vehicle_state.configure_missing()
+        old_shutdown = self.vehicle_state.last_car_shutdown
+        self.vehicle_state.set_refresh_mode(RefreshMode.CHARGING_DETECTION, "test")
+        self.publisher.map.clear()
+        result = self.vehicle_state.should_refresh()
+        assert result is True
+        assert self.vehicle_state.last_car_shutdown >= old_shutdown
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.CHARGING_DETECTION.value,
+        )
+
+    def test_should_refresh_charging_detection_reverts_to_previous(self) -> None:
+        self.vehicle_state.configure_missing()
+        # Previous mode is PERIODIC (set by configure_missing)
+        self.vehicle_state.set_refresh_mode(RefreshMode.CHARGING_DETECTION, "test")
+        self.vehicle_state.should_refresh()
+        assert self.vehicle_state.refresh_mode == RefreshMode.PERIODIC
+
+    def test_should_refresh_charging_detection_from_off_reverts_to_off(self) -> None:
+        self.vehicle_state.configure_missing()
+        self.vehicle_state.set_refresh_mode(RefreshMode.OFF, "test")
+        self.vehicle_state.set_refresh_mode(RefreshMode.CHARGING_DETECTION, "test")
+        self.vehicle_state.should_refresh()
+        assert self.vehicle_state.refresh_mode == RefreshMode.OFF
+
+    def test_periodic_inactive_publishes_inactive_phase(self) -> None:
+        self.vehicle_state.configure_missing()
+        # Ensure the car is inactive and grace period has passed
+        self.vehicle_state.hv_battery_active = False
+        self.vehicle_state.last_car_shutdown = datetime.datetime.min.replace(
+            tzinfo=datetime.UTC
+        )
+        self.vehicle_state.last_car_activity = datetime.datetime.min.replace(
+            tzinfo=datetime.UTC
+        )
+        self.vehicle_state.last_successful_refresh = datetime.datetime.now(
+            tz=datetime.UTC
+        )
+        self.publisher.map.clear()
+        result = self.vehicle_state.should_refresh()
+        assert result is False
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.INACTIVE.value,
+        )
+
+    def test_periodic_after_shutdown_publishes_after_shutdown_phase(self) -> None:
+        self.vehicle_state.configure_missing()
+        # Car just shut down, grace period active
+        self.vehicle_state.hv_battery_active = False
+        self.vehicle_state.last_car_shutdown = datetime.datetime.now(
+            tz=datetime.UTC
+        )
+        self.vehicle_state.last_car_activity = datetime.datetime.min.replace(
+            tzinfo=datetime.UTC
+        )
+        self.vehicle_state.last_successful_refresh = datetime.datetime.now(
+            tz=datetime.UTC
+        )
+        self.publisher.map.clear()
+        result = self.vehicle_state.should_refresh()
+        # Should not refresh yet (just refreshed) but phase should be after_shutdown
+        assert result is False
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.AFTER_SHUTDOWN.value,
+        )
+
+    def test_charging_stop_triggers_after_shutdown_grace(self) -> None:
+        """End-to-end: charging stops -> last_car_shutdown resets -> after_shutdown phase."""
+        self.vehicle_state.configure_missing()
+        # Car is parked (off), only charging keeps it "active"
+        self.vehicle_state.hv_battery_active = False
+        self.vehicle_state.is_charging = True
+        self.vehicle_state._VehicleState__had_significant_charging_power = True
+        self.vehicle_state.hv_battery_active = True
+        # Simulate a recent successful refresh
+        self.vehicle_state.last_successful_refresh = datetime.datetime.now(
+            tz=datetime.UTC
+        )
+        self.vehicle_state.last_car_activity = datetime.datetime.min.replace(
+            tzinfo=datetime.UTC
+        )
+        # Charging stops (e.g. phase switch) — car itself is off
+        self.vehicle_state.is_charging = False
+        self.vehicle_state.hv_battery_active = False
+        self.publisher.map.clear()
+        self.vehicle_state.should_refresh()
+        # Grace period is now active, phase should be after_shutdown
+        self.assert_mqtt_topic(
+            self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE),
+            PollingPhase.AFTER_SHUTDOWN.value,
+        )
+
     @staticmethod
     def get_topic(sub_topic: str) -> str:
         return f"/vehicles/{VIN}/{sub_topic}"