I noticed that my Powerwalls (3) were not charging or discharging. I called Tesla support. Tier1 support and I tried lots of diagnostics and then it was allegedly turned over to Tier2 who were to call me back. A week later, no call. so I called Tesla. I was referred to scheduling to set up a time for a tech to come out and look at the system. The first available slot was more than four weeks from today! That will make at least six weeks that my Powerwalls are useless to me. No load shifting, no backup.
On my current TOU plan that means that most of the power I will send to the grid will be off-peak, and I will draw power from the grid and not the Powerwalls during peak. This messes with the ROI of the system. And I am a bit chapped about having $26K of batteries doing nothing while the warranty ticks down. But Tesla sees nothing compensation-worthy.
So, if you are in Northern California and considering going with Tesla for a Powerwall installation, I have one piece of advice. Don't.