Thank you for your patience, and sorry to hear that you're experiencing this. I know that keeping your Nest devices charged is very important, and I would love to help you out. When it comes to keeping your Nest Doorbell (battery) or Nest Cam (battery) up and running, here are some articles and troubleshooting guides for the best charging practices:
I hope those articles help shed some light on charging and maintaining battery levels of your Nest doorbell or camera. Please let me know if you need further assistance.