Does Tesla Powerwall need internet?

Powerwall 3 requires an internet connection in order to commission the system.  Tesla recommend installers set up both hard wired and wireless connections where possible to give the best chance of a good connection for monitoring, controlling and free software updates.

If Powerwall is not connected to the internet, it will continue to operate in the last operating mode set and provide backup power during an outage, but it will not provide remote monitoring via the Tesla app. Extended periods without an active internet connection will prevent software updates and may impact the product warranty.