[Hammy]

What’s the quickest way to start preconditioning without pre-setting the departure time? And how long does it take to warm the battery in order to get best mileage?

 

[BMWiX192]

Not sure if you are asking about car's climate temperature settings or battery pre-warming to prepare for charging?
For car's climate if I have not set up the departure time, just go to car 5 minutes before departure and turn on climate while car is connected to charging cable. Within minutes it cools down the car then you can unplug the charger.

I noticed warming battery would be needed to colder places. So far in California hot sunny weather, I didn't need to prepare much. Just plugged to DC charger and it started charging with high speed. It will be different story as weather starts to cool down. I assume as when you decide to go to charger or 5 minutes before you arrive to charger, just select the charging location on navigation. It should start preparing the battery for charging.