You are correct about the timer function. I have had the timer finish up an hour or so before the entered departure time, but your experience is way beyond that! Now, I am using the Audi-charger, so I cannot speak to other commercial chargers. From my perspective, are you sure you activated the timer before you plugged in the car? Based on my experience, when you turn off the car a screen pops up in the MMI giving you the option to start the heater or to set a timer. Any timer you have set up in MyAudi app and which you have enabled should appear. You press the desired timer and a red bar should appear at the top of the icon box to indicate that it is active. Then, when you plug the cable into the car, it should start flashing white five or six times while it negotiates with the charging box. At that point it should start to flash green RAPIDLY, indicating that the car is waiting for a timer (eventually the lights will go out). If you plugged the car in and, instead of it flashing rapidly, the green light pulses slowly, then the timer has not been set and your car has immediately started to charge.