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