Battery life will depend on factors including activity, temperature, and camera settings that you select. You can extend the battery life of your camera by adjusting video quality, length of video clips, time between recorded events, and using activity zones to monitor specific areas. Here are some typical scenarios:
Busy: About 1.5 months battery life (about 20 - 25 recorded events per day)
Typical: About 3 months battery life (about 9 - 12 recorded events per day)
Quiet: About 7 months battery life (about 2 - 4 recorded events per day)
Also, Nest Cam only takes around 4-5 hours to fully charge the battery.