@JoeJanicek
We've had a battery camera for over 4 years, plugged in with the optional power cable. We have a Google Home Premium Advanced subscription, so we have 24/7 video history for the last 10 days and event video history for the last 60 days, accessed via the Google Home app. We have the same coverage for our old 1st gen cameras and doorbells in the Google Nest app.
If we had a Google Home Premium Standard Subscription, we would have event video history for the last 30 days. For our battery camera, without a Subscription we would have event video history for the most recent 3 hours.
It has always been true that if we want to save video history outside of these limits, we have to manually create and save video clips, which we can then download:
https://support.google.com/googlenest/answer/9207572
Saving video clips has nothing at all to do with your camera's memory, and we've never been able to delete individual clips from our camera's video history. We can only delete clips from our saved clips.
