Fix battery percentage calculation (3600mV=0%, 4100mV=100%)

Co-authored-by: kylegordon <231528+kylegordon@users.noreply.github.com>

Author: Copilot

custom_components/pettracer/device_tracker.py

@@ -156,16 +156,16 @@ def battery_level(self) -> int | None:
         """Return the battery level of the device."""
         device = self._get_device_data()
         if device and device.bat:
-            # Convert from millivolts to percentage (rough estimate)
-            # Typical LiPo: 4.2V full, 3.0V empty
-            # 4200mV = 100%, 3000mV = 0%
+            # Convert from millivolts to percentage
+            # Based on actual PetTracer device behavior:
+            # 4100mV = 100%, 3600mV = 0%
             mv = device.bat
-            if mv >= 4200:
+            if mv >= 4100:
                 return 100
-            elif mv <= 3000:
+            elif mv <= 3600:
                 return 0
             else:
-                return int(((mv - 3000) / 1200) * 100)
+                return int(((mv - 3600) / 500) * 100)
         return None
 
     @property

custom_components/pettracer/sensor.py

@@ -131,16 +131,16 @@ def native_value(self) -> int | None:
         """Return the state of the sensor."""
         device = self._get_device_data()
         if device and device.bat:
-            # Convert from millivolts to percentage (rough estimate)
-            # Typical LiPo: 4.2V full, 3.0V empty
-            # 4200mV = 100%, 3000mV = 0%
+            # Convert from millivolts to percentage
+            # Based on actual PetTracer device behavior:
+            # 4100mV = 100%, 3600mV = 0%
             mv = device.bat
-            if mv >= 4200:
+            if mv >= 4100:
                 return 100
-            elif mv <= 3000:
+            elif mv <= 3600:
                 return 0
             else:
-                return int(((mv - 3000) / 1200) * 100)
+                return int(((mv - 3600) / 500) * 100)
         return None
 
 

tests/test_device_tracker.py

@@ -78,21 +78,20 @@ async def test_device_tracker_battery_conversion(hass, mock_device):
     coordinator = MagicMock()
     coordinator.data = {"devices": [mock_device]}
 
-    # Test with 4100mV (mid-range)
+    # Test with 4100mV (full battery)
     mock_device.bat = 4100
     tracker = PetTracerDeviceTracker(coordinator, mock_device)
     battery = tracker.battery_level
-    assert battery is not None
-    assert 80 <= battery <= 95
+    assert battery == 100
 
-    # Test with full battery (4200mV)
+    # Test with above max (4200mV should cap at 100%)
     mock_device.bat = 4200
     coordinator.data = {"devices": [mock_device]}
     battery = tracker.battery_level
     assert battery == 100
 
-    # Test with low battery (3000mV)
-    mock_device.bat = 3000
+    # Test with low battery (3600mV = 0%)
+    mock_device.bat = 3600
     coordinator.data = {"devices": [mock_device]}
     battery = tracker.battery_level
     assert battery == 0

tests/test_sensor.py

@@ -85,10 +85,9 @@ async def test_battery_sensor(hass, mock_device):
     assert sensor.native_unit_of_measurement == "%"
     assert sensor.state_class == SensorStateClass.MEASUREMENT
 
-    # Test battery conversion (4100mV should be around 91%)
+    # Test battery conversion (4100mV should be 100%)
     battery = sensor.native_value
-    assert battery is not None
-    assert 80 <= battery <= 95
+    assert battery == 100
 
 
 async def test_battery_voltage_sensor(hass, mock_device):
@@ -422,3 +421,45 @@ async def test_sensor_no_details(hass):
 
     device_info = sensor.device_info
     assert device_info["sw_version"] is None
+
+
+async def test_battery_percentage_edge_cases(hass, mock_device):
+    """Test battery percentage calculation with edge cases."""
+    from custom_components.pettracer.sensor import PetTracerBatterySensor
+
+    coordinator = MagicMock()
+    coordinator.data = {"devices": [mock_device]}
+
+    sensor = PetTracerBatterySensor(coordinator, mock_device)
+
+    # Test minimum voltage (3600mV = 0%)
+    mock_device.bat = 3600
+    assert sensor.native_value == 0
+
+    # Test maximum voltage (4100mV = 100%)
+    mock_device.bat = 4100
+    assert sensor.native_value == 100
+
+    # Test below minimum (should cap at 0%)
+    mock_device.bat = 3500
+    assert sensor.native_value == 0
+
+    # Test above maximum (should cap at 100%)
+    mock_device.bat = 4200
+    assert sensor.native_value == 100
+
+    # Test mid-range (3850mV = 50%)
+    mock_device.bat = 3850
+    assert sensor.native_value == 50
+
+    # Test 3800mV (should be 40%)
+    mock_device.bat = 3800
+    assert sensor.native_value == 40
+
+    # Test 3900mV (should be 60%)
+    mock_device.bat = 3900
+    assert sensor.native_value == 60
+
+    # Test 4000mV (should be 80%)
+    mock_device.bat = 4000
+    assert sensor.native_value == 80