All Audi high-voltage batteries for Audi fully electric models have been designed to last the entire lifecycle of the car. They have been fully crash tested and come with an eight year, or 160,000 km warranty - whichever comes first. However, like a mobile phone battery, once your car’s battery passes 80% charge, the charging speed slows down to protect the battery’s longevity. In addition, for fully electric cars such as e-tron, we recommend when charging using DC chargers to set the charging target to 80%. This will accommodate most everyday journeys and will protect your battery. If you’re going on a longer journey, it’s fine to fully charge the battery.