In the most recent software versions, (2.17.X) I've noticed Tesla has added a new function that records the AC waveform during charging. Here's an example of the data graphed: The data is stored on the Gateway's 4G SD card located in the MCU. Each file appears to contain three 2.6k 16bit samples of approximately one cycle of the AC waveform. It's not clear if these are being recorded when there is a disturbance, at regular intervals, or both. The files are named as hex versions of the UNIX timestamp and located in a directory called CHG_WVFM. Pretty neat though!