Audi launches premiere of new online format series Audi TechTalk

Audi has launched a new online format series, Audi TechTalk, which focuses on interactions between media representatives and experts from Audi.

Journalists from all over the world will be able to learn more about the people and technology behind Audi and its new products. The premiere of the Audi TechTalk examines a topic crucial to the success of electric mobility - charging technology.

With the launch of Audi's first fully electric model, the Audi e-tron, Audi is helping customers around the world to integrate electric mobility into their everyday lives.

Together with two engineers from Technical Development, the first Audi TechTalk series opens with a discussion on charging speed and charging curves, and the influence of efficient cooling.

Charging speed is central to the use of an electric car. Drivers of a fully electric Audi model can benefit from high charging speeds because the charging capacity of up to 150kW is available for a large portion of the charging procedure. This is enabled by sophisticated thermal management of the lithium-ion battery.

Audi's first TechTalk explains how in order to assess the everyday usability of an electric car, customers should take not just the nominal maximum charging capacity but also the charging speed into account.

It is high charging speed (kWh/minute recharged), maintained over the entire charging process, that is essential for a short charging duration. In other words, a high charging capacity must be available for as long a period as possible. The e-tron models with their continuous output impress with precisely this property.

Under ideal conditions, the Audi e-tron is capable of charging from a 5% to 70% state-of-charge at the threshold of the maximum output before the intelligent battery management reduces the current. A major difference from other cars, which normally only reach their full output for a short time, and lower their power considerably before reaching the 70% threshold.

On a day-to-day basis, this means an elementary advantage: For a range of around 110km, it would need just under 10 minutes at the charging terminal. It reaches the 80% mark after approximately 30 minutes - both being rules of thumb for orientation in everyday circumstances with the e-tron models. Even though it takes much longer, for technical reasons, to fill the remaining 20% of a lithium-ion battery, fully charging at an High Power Charging terminal takes around 45 minutes - an outstanding characteristic in the competitive environment.

These technical advantages not only ensure the high suitability of the e-tron models for everyday use but also significantly enhance the reliability of planning charging stops on long-distance trips.

The lithium-ion battery of the Audi e-tron 55 has a gross capacity of 95kWh and has been designed for a long lifecycle. Liquid cooling ensures that the battery's temperature remains in the optimum range of 25 to 35 degrees Celsius, even at high stress levels or low temperatures.

During direct-current charging with 150kW, cold coolant takes away the heat that occurs as a result of electrical internal resistance in the battery. The core of the cooling system is made up of extruded profiles - visually comparable with a slatted frame - which have been affixed to the battery system from below.

A newly developed, thermally conductive adhesive joins the cooling unit to the battery housing. The gel evenly transfers the waste heat produced by the cells to the coolant via the battery housing. The spatial separation of elements and battery cells carrying cooling water also increases the overall system's safety.