diff --git a/homeassistant/components/chromecast.py b/homeassistant/components/chromecast.py
index 1736f0d2444..12591e3af92 100644
--- a/homeassistant/components/chromecast.py
+++ b/homeassistant/components/chromecast.py
@@ -298,7 +298,7 @@ def setup(hass, config):
                 pychromecast.play_youtube_video(video_id, cast.host)
                 update_chromecast_state(entity_id, cast)
 
-    hass.track_time_change(update_chromecast_states)
+    hass.track_time_change(update_chromecast_states, second=[0, 15, 30, 45])
 
     hass.services.register(DOMAIN, SERVICE_TURN_OFF,
                            turn_off_service)
diff --git a/homeassistant/components/device_tracker/__init__.py b/homeassistant/components/device_tracker/__init__.py
index 04cea3e047b..956d2f3957f 100644
--- a/homeassistant/components/device_tracker/__init__.py
+++ b/homeassistant/components/device_tracker/__init__.py
@@ -128,7 +128,8 @@ class DeviceTracker(object):
         if self.invalid_known_devices_file:
             return
 
-        hass.track_time_change(update_device_state)
+        hass.track_time_change(
+            update_device_state, second=[0, 12, 24, 36, 48])
 
         hass.services.register(DOMAIN,
                                SERVICE_DEVICE_TRACKER_RELOAD,