@sorka you are making some good points. Having driven many road trips where I have driven continuously from charging to 'empty' I have also noticed that the amount of energy one can take out of the battery varies. Fast driving with high energy consumption, lots of hard acceleration makes less energy available. 'Gentle' driving will allow more energy to be available. I was able to see that in two ways. #1 when the battery drops down to say 10% at the end of a 2 hour drive, the battery voltage seems to be a little higher when the car was driven carefully compared to when I was driving very fast or with lots of sprints.
The other, more obvious way to see the difference is measuring the amount of energy taken out during a longer drive. If I start with 50 kWh remaining in the battery, the amount of energy I am able to get out is usually between 49.6 and 49.1 depending on how I drive. Driving with high power causes higher losses inside the battery.