Battery Saver
WARNING: This page is about a different car, the 2017 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The battery saver feature is uses to save battery voltage. The BCM provides automatic shut-off of the interior and exterior lamps after a time-out period when the ignition is off.
For more information regarding the interior lighting battery saver feature, Refer to: Interior Lighting - System Operation and Component Description .