As per the new Tesla app update they mention being able to preheat your battery but not how.
That's because you can't force it on. If your car is cold enough and you start the auto climate control remotely after a minute or two it will kick on and show you the battery heat icon. However, this is no way to force it on.
There are new flags in the API that let the app know the battery heater is on. When it's on it really sucks juice. I had my UMC set to 40A at home and with the climate control and battery heater on I was getting 3 MPH charging rate while I'd normally get 26 MPH.
That's because you can't force it on. If your car is cold enough and you start the auto climate control remotely after a minute or two it will kick on and show you the battery heat icon. However, this is no way to force it on.
There are new flags in the API that let the app know the battery heater is on. When it's on it really sucks juice. I had my UMC set to 40A at home and with the climate control and battery heater on I was getting 3 MPH charging rate while I'd normally get 26 MPH.