The videos are stored in the mobile app and you can view them when you need. The camera captures videos when it detects an event, e.g., a person, encrypts them, and sends them to the mobile app. The app decrypts them and stores them locally, allowing the user to view them when needed. The app also allows for livestreaming and it keeps the livestreamed video locally as well.
So only when viewing the steam or also receiving in background? If in the background that means wiping the battery in no-time.