diff --git a/src/bthome_ble/__init__.py b/src/bthome_ble/__init__.py
index 93b02f2..37e2531 100644
--- a/src/bthome_ble/__init__.py
+++ b/src/bthome_ble/__init__.py
@@ -13,14 +13,11 @@
     Units,
 )
 
-from .const import SLEEPY_BINARY_SENSORS, SLEEPY_SENSORS
 from .parser import BTHomeBluetoothDeviceData
 
 __version__ = "2.10.1"
 
 __all__ = [
-    "SLEEPY_BINARY_SENSORS",
-    "SLEEPY_SENSORS",
     "BinarySensorDeviceClass",
     "BTHomeBluetoothDeviceData",
     "DeviceClass",
diff --git a/src/bthome_ble/const.py b/src/bthome_ble/const.py
index 28746cd..bbd74a0 100644
--- a/src/bthome_ble/const.py
+++ b/src/bthome_ble/const.py
@@ -343,21 +343,3 @@ class MeasTypes:
         factor=0.001,
     ),
 }
-
-
-SLEEPY_BINARY_SENSORS = {
-    "door",
-    "garage_door",
-    "lock",
-    "opening",
-    "presence",
-    "tamper",
-    "vibration",
-    "window",
-}
-
-
-SLEEPY_SENSORS = {
-    "count",
-    "mass",
-}
diff --git a/src/bthome_ble/parser.py b/src/bthome_ble/parser.py
index a7e235d..9b56845 100644
--- a/src/bthome_ble/parser.py
+++ b/src/bthome_ble/parser.py
@@ -116,14 +116,14 @@ def __init__(self, bindkey: bytes | None = None) -> None:
         # Encryption to expect, based on flags in the UUID.
         self.encryption_scheme = EncryptionScheme.NONE
 
-        # If true, then we know the actual MAC of the device.
+        # If True, then we know the actual MAC of the device.
         # On macOS, we don't unless the device includes it in the advertisement
         # (CoreBluetooth uses UUID's generated by CoreBluetooth instead of the MAC)
         self.mac_known = sys.platform != "darwin"
 
-        # If true then we have used the provided encryption key to decrypt at least
+        # If True then we have used the provided encryption key to decrypt at least
         # one payload.
-        # If false then we have either not seen an encrypted payload, the key is wrong
+        # If False then we have either not seen an encrypted payload, the key is wrong
         # or encryption is not in use
         self.bindkey_verified = False
 
@@ -136,6 +136,9 @@ def __init__(self, bindkey: bytes | None = None) -> None:
         # value with a new bindkey.
         self.last_service_info: BluetoothServiceInfo | None = None
 
+        # If this is True, the device is not sending advertisements in a regular interval
+        self.sleepy_device = False
+
     def supported(self, data: BluetoothServiceInfo) -> bool:
         if not super().supported(data):
             return False
@@ -255,6 +258,19 @@ def _parse_bthome_v2(
         else:
             self.encryption_scheme = EncryptionScheme.NONE
 
+        # If True, the first 6 bytes contain the mac address
+        mac_included = adv_info & (1 << 1)  # bit 1
+        if mac_included:
+            bthome_mac_reversed = data[1:7]
+            mac_readable = to_mac(bthome_mac_reversed[::-1])
+            payload = data[7:]
+        else:
+            mac_readable = service_info.address
+            payload = data[1:]
+
+        # If True, the device is not updating regularly
+        self.sleepy_device = bool(adv_info & (1 << 2))  # bit 2
+
         # Check BTHome version
         sw_version = (adv_info >> 5) & 7  # 3 bits (5-7)
         if sw_version == 2:
@@ -298,15 +314,6 @@ def _parse_bthome_v2(
         self.set_title(f"{name} {identifier}")
         self.set_device_type(device_type)
 
-        mac_included = adv_info & (1 << 1)  # bit 1
-        if mac_included:
-            bthome_mac_reversed = data[1:7]
-            mac_readable = to_mac(bthome_mac_reversed[::-1])
-            payload = data[7:]
-        else:
-            mac_readable = service_info.address
-            payload = data[1:]
-
         if self.encryption_scheme == EncryptionScheme.BTHOME_BINDKEY:
             if len(mac_readable) != 17 and mac_readable[2] != ":":
                 # On macOS, we get a UUID, which is useless for BTHome sensors
diff --git a/tests/test_parser_v2.py b/tests/test_parser_v2.py
index e6b09dd..7d98887 100644
--- a/tests/test_parser_v2.py
+++ b/tests/test_parser_v2.py
@@ -120,6 +120,36 @@ def test_encryption_no_key_needed():
     assert not device.bindkey_verified
 
 
+def test_sleepy_device():
+    """Test that we can detect that a device that doesn't update regularly."""
+    data_string = b"\x44\x04\x13\x8a\x01"
+    advertisement = bytes_to_service_info(
+        payload=data_string,
+        local_name="ATC_8D18B2",
+        address="A4:C1:38:8D:18:B2",
+    )
+
+    device = BTHomeBluetoothDeviceData()
+
+    assert device.supported(advertisement)
+    assert device.sleepy_device
+
+
+def test_no_sleepy_device():
+    """Test that we can detect that a device that updates regularly."""
+    data_string = b"\x40\x04\x13\x8a\x01"
+    advertisement = bytes_to_service_info(
+        payload=data_string,
+        local_name="ATC_8D18B2",
+        address="A4:C1:38:8D:18:B2",
+    )
+
+    device = BTHomeBluetoothDeviceData()
+
+    assert device.supported(advertisement)
+    assert not device.sleepy_device
+
+
 def test_mac_as_name():
     """
     A sensor without a name gets its MAC address as name from BluetoothServiceInfo.