The Quick-Release Battery Pack gives you backup power for your Ring Video Doorbell 2. To charge your battery pack, connect it to a micro-USB cord and plug it into a power outlet. When the battery pack in your Ring Video Doorbell 2 runs out of power, you can replace the batteries by pulling off the faceplate on your Doorbell and pressing the quick-release tab. Then you can slide your backup battery pack into your Ring Video Doorbell 2, reconnect the faceplate, and you're good to go.