We have two Powerwall 2 batteries installed in our garage configured to run in Self-Powered mode. Most nights, the Powerwalls will fully discharge before the system starts drawing from the grid. However, I am noticing that sometimes the batteries will still have a decent amount of charge left but will be drawing from the grid rather than discharging. This seems to be happening more frequently and always in the early hours of the morning around 2 or 3am.
For example, this morning the batteries had 22% charge remaining but the system was drawing from the grid between 3:10am and 6:10am before they started discharging again. This coincided with the time that the solar kicked back into life and started generating power again.