Special Modes of Operation
Outside its normal modes of operation (see Modes of Operation without Solar and Modes of Operation with Solar), Powerwall also has special modes. Powerwall identifies unique situations and then automatically switches either to Preconditioning or Storm Watch to enhance performance.
When temperatures are below freezing, Preconditioning slowly heats Powerwall for improved operation and charging performance. Powerwall detects temperature change and preheats accordingly.
Preconditioning draws a small amount of power in preparation for high-power charging. During a cold night, Powerwall automatically preheats a few hours before sunrise so that maximum solar energy can be captured during the day.
During Preconditioning, the Power Flow screen may show energy flowing to Powerwall from solar and or the utility grid.
When a storm or severe weather is on the horizon, increasing the likelihood of a utility power outage, Powerwall triggers Storm Watch. This mode automatically charges Powerwall to maximum capacity so it can provide backup power.
The Tesla app notifies customers that Powerwall has activated Storm Watch. The mode remains active until the weather event ends, at which time the system returns to its previously selected mode. It is possible to disable this mode by going to the Tesla app, selecting 'Customize' and then 'Storm Watch.'