View battery levels on sensors

[Loki]

There’s a Wishlist topic for that here:

Notification when sensor moves out of range, or battery dies or gets below 20%

It would be useful for a mobile application I’m imagining if a notification could be sent when a sensor moves out of range of its bridge. It would also be useful if a notification could be sent when a sensor battery dies. Perhaps this would be indistinguishable from the sensor moving out of range, but that would be OK.