Thank you Morgan.
I do not see voltage indicators via Ring Web site or MQTT. Just percentage of battery life.
Here is what the PIR shows today.
{"batteryLevel":85,"batteryStatus":"ok","commStatus":"ok","firmwareStatus":"up-to-date","lastCommTime":"2021-05-11T08:34:21Z","lastUpdate":"2021-05-11T08:34:21Z","linkQuality":"ok","serialNumber":"GXXX","tamperStatus":"ok"}