diff --git a/src/uiprotect/data/devices.py b/src/uiprotect/data/devices.py
index 26229b2c..62924f8a 100644
--- a/src/uiprotect/data/devices.py
+++ b/src/uiprotect/data/devices.py
@@ -7,7 +7,7 @@
 import warnings
 from collections.abc import Callable
 from datetime import datetime, timedelta
-from functools import cache
+from functools import cache, lru_cache
 from ipaddress import IPv4Address
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Literal, cast
@@ -25,6 +25,7 @@
     convert_video_modes,
     from_js_time,
     serialize_point,
+    timedelta_total_seconds,
     to_js_time,
     utc_now,
 )
@@ -900,6 +901,15 @@ class CameraAudioSettings(ProtectBaseObject):
     style: list[AudioStyle]
 
 
+@lru_cache
+def _chime_type_from_total_seconds(total_seconds: float) -> ChimeType:
+    if total_seconds == 0.3:
+        return ChimeType.MECHANICAL
+    if total_seconds > 0.3:
+        return ChimeType.DIGITAL
+    return ChimeType.NONE
+
+
 class Camera(ProtectMotionDeviceModel):
     is_deleting: bool
     # Microphone Sensitivity
@@ -1855,11 +1865,13 @@ async def set_glass_break_detection(self, enabled: bool) -> None:
 
     @property
     def chime_type(self) -> ChimeType:
-        if self.chime_duration.total_seconds() == 0.3:
-            return ChimeType.MECHANICAL
-        if self.chime_duration.total_seconds() > 0.3:
-            return ChimeType.DIGITAL
-        return ChimeType.NONE
+        return _chime_type_from_total_seconds(
+            timedelta_total_seconds(self.chime_duration)
+        )
+
+    @property
+    def chime_duration_seconds(self) -> float:
+        return timedelta_total_seconds(self.chime_duration)
 
     @property
     def is_digital_chime(self) -> bool:
diff --git a/src/uiprotect/utils.py b/src/uiprotect/utils.py
index f8a99ae8..dd45b297 100644
--- a/src/uiprotect/utils.py
+++ b/src/uiprotect/utils.py
@@ -670,3 +670,8 @@ def make_required_getter(ufp_required_field: str) -> Callable[[T], bool]:
     if "." not in ufp_required_field:
         return partial(get_top_level_attr_as_bool, ufp_required_field)
     return partial(get_nested_attr_as_bool, tuple(ufp_required_field.split(".")))
+
+
+@lru_cache
+def timedelta_total_seconds(td: timedelta) -> float:
+    return td.total_seconds()
diff --git a/tests/data/test_camera.py b/tests/data/test_camera.py
index 57169a09..0632f498 100644
--- a/tests/data/test_camera.py
+++ b/tests/data/test_camera.py
@@ -495,7 +495,8 @@ async def test_camera_set_chime_duration_duration(
     camera_obj.api.api_request.reset_mock()
 
     camera_obj.feature_flags.has_chime = True
-    camera_obj.chime_duration = 300
+    camera_obj.chime_duration = timedelta(seconds=300)
+    assert camera_obj.chime_duration_seconds == 300
     camera_obj.mic_volume = 10
 
     if duration in {-1, 20}: