Does anyone know if there is a way to use the Tesla Powerwall notification when the grid goes down, so that I could use it in a program to shut down  non-essential lighting to save battery power?  Don't know if this is possible, but would be cool!

Are you looking for notifications in udiMobile - or and automation in the AC

I have not looked at notifications in udiMobile - will put it on my list to do 

You can easily make an ISY/AC automation to shut down when off grid and batter is below XX%

 

If
        'PWname' Grid Status is not on grid
    And 'PWname' Remaining Battery  < XX%
 
Then
        
        // Shut down some devices
 
 
Else
   - No Actions - (To add one, press 'Action')
 

OK, question on installing the NS:

 

• I have three powerwall 3s but only see two of them on my wifi network.  Can I pick either one of the two for the IP address?
• The configuration says it neeed a reset token, but the web address does not work for me : https://play.google.com/store/apps/details?id=net.leveugle.teslatokens

Are you using the old or the new powerwall nodeserver (udiTeslaPW2) The latest should not need the token ( it gets it automatically).  

I have 2 powerwalls as well (older version). I only need one IP address for both. I think the IP address may be wifi and Ethernet but i do not know the latest versions