Verify the battery is in good health by removing the front plastic enclosure/lens and verifying the LED begins blinking for approximately 2 minutes.
If no LED blinking occurs when removing the lens, replace the battery
Note: The LED blinking will only be visible during the 2 minute sensor stabilization period (after re-adding the lens, and then for a subsequent 15 minute walk-test mode. During this mode the LED will blink each time motion is sensed. After this period, the LED will no longer illuminate.