Hi RonNOR,
Thanks for posting here. Yes, the wired Nest Protect does have backup batteries. These batteries are designed to provide power to the Nest Protect in the event of an AC power outage. They ensure that the device continues to function and provide protection even when the power is out.
When the AC power is restored after an outage, the backup batteries in the wired Nest Protect are automatically recharged. This ensures that the device is ready for future power outages and can continue operating as intended. The Nest mobile app does not specifically indicate the battery level or the need for recharging the backup batteries in the Nest Protect. However, the app will alert you if there is a low battery condition or if there are any issues with the Nest Protect's operation. You will receive notifications on your mobile device and can also check the status of each Nest Protect device in the app.
Let us know if that helps.
Best,
Zoe
