Audi R8 e-tron In Detail
The Audi R8 e-tron will be rare car on the roads in Europe as small-scale production at the Audi Neckarsulm site in the Böllinger Höfe will be limited to individual request, and in the US it will not be offered at all.
This will not stop us from taking a look inside this EV to check out its Tesla-style lithium-ion battery.
Audi decided to re-design the early version of R8 e-tron, so the new version uses small cylindrical cells…a lot of them. The whole pack consists of 7,488 cells packed in 52 modules of 144 cells each.
Total energy stands at over 90 kWh for 450 km (279.6 miles) range in NEDC cycle.
Unlike Tesla, the pack isn’t at the floor level, just in the rear and partially in the middle between the driver and passenger seat.
“The T-shaped battery is structurally integrated in the middle tunnel and is mounted behind the occupant cell – this location offers a low center of gravity and an axle load distribution of 40:60 (front/rear). The high-voltage battery is based on lithium-ion technology. The liquid-cooled lithium-ion battery consists of 52 modules. Compared to the first e-tron technology platform, the energy capacity of the new 595 kg (1311.8 lb) battery system was boosted from around 48.6 kWh to 90.3 kWh without requiring any package modifications.
Thanks to the high energy density, which was increased from 84 to 152 Wh/kg, the R8 e-tron can be driven up to 450 km (279.6 mi) on just one battery charge – previously it was 215 km (133.6 mi). In the Combined Charging System (CCS) for charging with DC or AC electricity, the battery can be fully charged in well under two hours. The driver can control this process remotely by smartphone, if the user has installed the relevant Audi connect app.”
“The battery operates with 385 volts of nominal voltage, and its new cell module concept achieves excellent performance. The battery’s energy density grew from 84 watt-hours per kilogram (Wh/kg) to 152 Wh/kg, and its nominal capacity from 48.6 kWh to 90.3 kWh. Its driving range on a full charge has more than doubled – from 215 km (133.6 mi) to as much as 450 km (279.6 mi). These values make Audi the leader among the competition.
The battery system of the Audi R8 e-tron takes on the shape of a “T”. It measures 235 cm (92.5 in) long, 136 cm (53.5 in) wide and 70 cm (27.6 in) high, including the junction box on the cross-bar of the “T”. This junction box is responsible for monitoring, switching and transmitting an electrical current of over 1,200 amperes. The highly complex battery system consists of over 10,000 individual parts.
The 7,488 cells are packed in 52 modules of 144 cells each. Each module weighs 7.8 kg (17.2 lb). They are arranged on two and five levels (“floors”) in the tunnel battery and in the rear battery. Aluminum plates separate the “floors” from one another while creating the supporting structure for the battery.
Coolant circulates in a cooling system of aluminum shells. In a crash, high-strength floor plates and impact plates redirect the crash forces into the multimaterial ASF (Audi Space Frame) of the R8 e-tron in a defined way.”
Two electric motors drive the rear wheels. 340 kW and 460 Nm of torque is enough to reach 100 km/h (62.1 mph) in 3.9 seconds, but Tesla P85D quickness is out of reach for the R8 e-tron.
“The two electric motors on the rear axle each output 170 kW and 460 Nm (339.3 lb-ft) of torque. The R8 e-tron, which weighs just 1,841 kg (4058.7 lb) empty (without driver), sprints from 0 to 100 km/h (62.1 mph) in 3.9 seconds and can accelerate to an electronically governed top speed of 250 km/h (155.3 mph) while developing its unique e-sound. Targeted Torque Vectoring – a need-based distribution of drive power between the rear wheels – gives the car maximum stability and dynamism.
Intelligent energy management and an electromechanical brake system at the rear axle ensure high rates of energy recuperation. The suspension springs consist of glass fiber reinforced polymer (GFRP), and the anti-roll bar is made of CFRP.”
Despite the massive battery system 595 kg (1311.8 lb), curb weight is 1,841 kg (4058.7 lb) thanks to aluminum and carbon fibers.
Audi prepared two charging options – 7.2 kW AC in 12 hours or DC charging (combo) in 95 minutes at 50 kW.
Audi is working on a 150 kW, which would threaten Tesla Supercharger supremacy for sure.
“The Combo 2 charging interface of the Combined Charging System in the Audi R8 e-tron enables charging with AC or DC electricity. When charging with AC from an industrial electrical outlet with 7.2 kW of charging power, a full charge is reached in just around 12 hours. Charging with DC electricity shortens the time – to just 95 minutes at a charging power of 50 kW. Audi is demonstrating charging equipment that can charge this battery system with up to 150 kW of charging power. For the driver of the R8 e-tron, this means that a driving range of around 150 km (93.2 mi) can be attained after just 15 minutes of charging time. The customer can manage charging remotely as well – using a smartphone on which the customer has installed the relevant Audi connect app.”