Article Summary:
The micro-USB port on the back of Nest Protect is to make sure that a Nest support team member has every option available when troubleshooting your device. You should only use it when directed by a Nest support team member.

You’ll probably never need to use the USB port. It’s not for charging the batteries or any regular use. However, for some troubleshooting cases, a Nest support team member may ask you to plug a micro-USB cable into the connector.