Average PV power: 3kw.

 Rain overnight, very cloudy all day.  

After noon, I decided the PowerWall batteries were not going to get recharged by the end of the day.  The charge level declined to ~65% after a dawn level of about 80%.  The problem is that the PW isn't configured with CT "clamps" on all sources of PV power and was allowing some of my PV power to make it to the grid.   My PW will charge the battery with only about half my PV power.   Peak sunny PV power in this season has been about 20kw though it goes above 25kw during the peak season.

So, around 1pm, I told the PW  to disconnect from the grid.

With three 5kw batteries, my PW can charge at about 15kw.  Though I have not seen more than 7kw in the past.

At about 3pm, the charge level is about 85%.  And I hope it will be about 90% when the sun fails me.   That should be 4-5 pm.  With more clouds than sun, PV powers have been less than 10kw except for a few seconds when it went to about 18kw.   I'm heating the house with a 18 kbtu mini split which is using about 2-3 minutes near 2kw about every nine minutes.   So, most of my day time use is less than 1kwh each hour.  At that rate, the total capacity of a fully charged battery is 40-45 hours.  Over night, I typically keep the bedroom only warm for about 1/2 kwh/hour.  So, during "hard times" I can likely hunker down in the bedroom for ~90 hours if I can not charge while the sun is out.  "Hard times" means grid down for a long period with a long period of cloudy days.

With grid up and nice clear weather, it typically goes like this:

1) I start each evening with a fully charged battery.  6-8 pm depending on the season.

2) If I need modest heating or cooling overnight (in bedroom only), I get up in the morning with a charge level of around 80-85%.  

3) With good sun, the battery is usually fully charged around 11 am - noon.