Energy storage is provided by the lithium-ion battery, which is located in multiple blocks under the luggage compartment floor, under the rear seat and in the center tunnel. It stores 26.5 kWh of usable energy at 380 volts and weighs 300 kilograms (661 lb). Water flows around the 30 modules which constitute this battery; the waste heat is utilized to heat the vehicle’s interior. At low temperatures, the system is aided by an electric PTC heating element; an air conditioner is activated in hot weather.

The power electronics module in the engine compartment converts the battery’s direct current (DC) to alternating current; a DC converter couples the 12-volt electrical system with the high-voltage system. The Audi A3 e-tron can be recharged in about nine hours with a 230-volt household socket.

On a single battery charge, this compact car can cover around 140 km (86.99 miles). It powers the car from zero to 100 km/h (62 mph) in 11.2 seconds and on up to a top speed of 145 km/h (90 mph).

The driver of the Audi A3 e-tron technology platform can use the driver profile button to choose between three modes. The active mode—dynamic, auto or efficiency—is shown in the display of the driver information system. In dynamic mode, the electric motor delivers its full power. The air conditioner can also be operated on full in this mode. In auto mode, both systems are throttled back somewhat to extend the range.

In efficiency mode, which is designed for maximum range, the output of the electric motor is limited to 50 kW (68 hp). The air conditioner operates in this mode with minimal energy input, and top speed is limited to 110 km/h (68 mph). The full power of the electric motor can be called up at any time in auto and efficiency modes with a simple kickdown.

The driver can also regulate the degree of energy recovery during braking and coasting phases by choosing from one of four recuperation levels via the gear selector lever or two paddles on the steering wheel.

If the lowest level is selected, the Audi A3 e-tron technology platform can “glide,” or roll freely, when the driver releases the accelerator. This is an anticipatory and comfortable way to drive. At the highest level, the car brakes strongly and the electric motor functions as a generator. When the driver steps on the brake, an electromagnetic brake booster pressurizes the hydraulic wheel brakes. The electric motor acts as a generator and recovers energy in this situation, too.

The Audi A3 e-tron pilot program is intended to allow Audi to identify challenges and opportunities with plug-in vehicles as progressive luxury car buyers become increasingly receptive to EV technology. By studying e-tron use across multiple geographical regions, Audi will monitor the effect of climate conditions, driving patterns and energy performance and use insight gained in the final development of future EV technology applications.

The A3 e-tron pilot program serves as an important innovation platform for Audi to develop greater insight into electric vehicles and how American driving conditions affect use of the progressive technology in everyday life. We will integrate the data generated from this program into the launch of a range of Audi e-tron models for American drivers.

—Jeff Curry, e-mobility and sustainability strategy lead at Audi of America

The e-tron name indicates that an advanced electrified power train with a plug-in capability is onboard. As a core philosophy of e-tron, Audi engineers are researching e-tron power concepts tailored to different vehicle types and driving needs including full battery-electric (BEV), plug-in hybrid (PHEV) and extended range electric (EREV) versions. In April 2011, Audi introduced a four-seat A3 e-tron concept plug-in hybrid vehicle in Shanghai. (Earlier post.)

Audi e-tron becomes the latest entry to Audi’s stable of ingredient technologies, including Audi ultra-lightweight construction, Audi TDI clean diesel, Audi connect navigation and infotainment and Audi’s signature quattro all-wheel drive.

Audi also is working on standardizing peripheral technologies that have to be taken into consideration for wide spread EV adoption and use, including driving the establishment in 2011 of common global standards for charging. As part of the pilot program, Audi will develop its network of infrastructure partners, test advanced services and create partnerships that will be central to providing the premium Audi experience for e-tron buyers.