The Audi A1 e-tron embodies an intelligent and sophisticated technological concept. A lithium-ion battery pack provides the energy for the electric drive. The driver generally charges the battery pack from the grid – most conveniently, from a home socket.
Full battery charging suffices for more than 50 km – in most cases that’s more than enough for daily commuting, as numerous studies have confirmed.
In the event that the driver wants to travel a longer distance, the mega city vehicle from Audi has a range extender on board – a small combustion engine that recharges the battery to extend the range beyond 250 km (155.34 miles). The Audi A1 e-tron always travels electrically – no sort of mechanical connection exists between the range extender and the driven front wheels.
The ancillary units of the A1 e-tron are electrified. A high-voltage refrigerant compressor operating according to the current power requirement drives the air conditioning system, for considerably greater efficiency compared with conventional concepts. The power steering operates electrohydraulically as in the series production model, and is therefore also especially energy efficient. The hydraulic brake system includes a brake servo, with the vacuum supplied by an electrically operated pump, also demand-controlled.
The compact 2-door vehicle affords all the strengths of the Audi A1 model series – a small turning radius, good clarity and high agility. The running gear is carefully tuned, combining pleasant comfort with a sporty character. Going with the trend of the future doesn’t entail the slightest sacrifice for the A1 e-tron, especially since the interior space and the luggage compartment capacity match those of series production models.
The Electric Motor
The synchronous motor of the Audi A1 e-tron is mounted transversely in the front, with its low installation benefiting the center of gravity. It has a continuous power of 45 kW (61 hp), with a torque of 150 Nm (110.63 lb-ft) already available from a standstill. The peak performance lies at 75 kW (102 hp), the maximum torque at 240 Nm (177.01 lb-ft). The powerful “little guy” from Audi thus accelerates in 10.2 seconds from 0 to 100 km/h (62.14 mph) and continues to a top speed of over 130 km/h (80.78 mph).
The torque flows to the front axle via a single-staged transmission flanged to the electric motor. The selector lever stems from the series production model, following the appropriate adaptation. The modes are “D”, “R”, “N” and “Range” – on this level the range extender is activated depending on the applied operating strategy; the electronic management system cuts in the extender with smooth transitions. The current load requirement and the energy level of the battery are the most important factors.
In the engine compartment next to the electric motor is the power electronics, which controls the electric traction. The DC converter coupling the 14 V electrical system to the high-voltage system, the switching unit for protecting the high-voltage components and the charging module are also accommodated in the front end.
Shaped like a “T”, the battery pack of the Audi A1 e-tron is located underneath the rear part of the center tunnel and under the rear seats – the ideal position for weight distribution. The lithium-ion battery, operating at 270 volts, has a normal energy level of 12 kWh, and is water-cooled to stay within an optimal temperature range.
The socket for the standard charge plug is located behind the rings in the single frame of the Audi A1 e-tron. A fully discharged battery requires less than three hours’ charging from a 230 V grid; a 380 V high-voltage current reduces the time to less than an hour under optimal conditions. A display next to the plug-in connection shows the remaining charging time and the charge state. This value and the current range also appear in the driver’s information display of the instrument cluster.
During travel the large electric motor driving the A1 e-tron can convert the deceleration energy into electric current and feed it back to the electrical system, by operating briefly as a generator. The energy return flow begins once the driver releases the accelerator.
The extent of the recuperation is controllable in five stages by rocker switches on the steering wheel. At stage 1 the deceleration is slight, and at stage 5 considerable. In urban traffic the A1 e-tron can recover through recuperation almost a third of the energy needed for driving. When the rocker switches lie at 0 and the driver releases the accelerator, the mega city vehicle needs no energy at all – it simply “glides”.
The Range Extender
A small single-disk rotary piston engine serves as the range extender on board the Audi A1 e-tron. It has a chamber capacity of 254 cc (15.5 cu in) and constantly runs at 5000 rpm in its optimal efficiency range. The rotary piston engine drives a generator that produces up to 15 kW (20 hp) electrical charging power.
The great strengths of the rotary piston engine are its vibration-free and practically noiseless operation, small dimensions and the extremely low weight. Including the generator, the entire assembly group weighs about 65 kg (143.30 lb). This weight already includes the special power electronics, the intake, exhaust and cooling systems as well as the acoustic encapsulation and the auxiliary frame.
According to the draft for standardization for determining the consumption of range extender vehicles, the rate of fuel consumption by the Audi A1 e-tron is just 1.9 liters per 100 km (123.80 US mpg) – a CO2 equivalent of only 45 g per km (72.42 g/mile). The fuel is supplied from a tank with a capacity of 12 liters (3.17 US gallons).
The Audi A1 e-tron is specially painted in “Aqua Mint, pearl effect”, while the roof contrast arch is “Dark High Gloss Steel”. The roof, the rear spoiler and other components are made from carbon fiber reinforced plastic (CFRP), underscoring Audi’s expertise in lightweight design.
Missing from the rear diffuser are the tailpipes – a solution highlighting the vehicle width and the emission-free drive. The “e-tron” lettering appears on the front fenders.
The Interior and Equipment
In the generously sized interior of the A1 e-tron the door cushioning and the center console are covered by Milan leather in titanium gray. Typically Audi, the operation and the display concept are entirely uncomplicated.
The equipment fulfills all the desires of an urban customer. Marked by a sporty lightness, the interior offers space and connection options for devices such as an iPod. Like every A1, the Audi A1 e-tron also stands for space, for music, for communication, for intelligence and for quality. And it stands for a contemporary lifestyle – for color and form, for freedom and individualism.
The equipment of the mega city vehicle from Audi also includes the LED interior lighting package and the top solution among the infotainment systems – the powerful MMI Navigation plus with 20 GB hard drive, high-definition 6.5-inch monitor and 3-dimensional map graphics.
The Audi A1 e-tron fully connects to the internet through a UMTS module, to provide the same state-of-the-art features as found in the Audi A8 flagship – navigation with map imagery from Google Earth and a WLAN hotspot for connecting passengers’ mobile terminal equipment, such as an iPad. The UMTS connection is fast, secure and free of additional charges.[wzslider height=”400″ lightbox=”true”]