To those that are able to gauge your charging levels (either using your own charger or public charging stations), what is the maximum amount of charge in kWh have you been able to put in your e-tron when the estimated range goes to zero? I have only been able to charge anywhere between 6.5 to 6.9 kWh using the ChargePoint station at work. I thought useable capacity for the battery is 7.7 kWh out of total 8.8 kWh?