1km downhill = 1km range, they claim.
German luxury carmaker Audi is set to unveil it’s first-ever series-production dedicated full-electric model very soon. The e-tron has previously been teased to discuss matters of aerodynamics and connectivity, but Ingolstadt’s teased the car once again, this time to bring up its ability to ‘recuperate’ electric energy when coasting.
When Audi brought the car to Pikes Peak, they thought it’d be the best place to collect some data on their newly-developed energy recuperation system. During the 31-kilometre downhill cruise, the e-tron was able to feed so much energy back into its battery pack that the electric range was up nearly 31km as a result. The e-tron is able to recuperate energy with as much as 300Nm of torque and 220kW of electric power, which is more than 70% of its operating energy input.
Audi attributes some 30% of the e-tron’s range to its energy recuperation system. The two electric motors on board work together with an electrohydraulically-integrated brake control system, offering three different energy recuperation modes at once. There’s automatic coasting recuperation using, manual coasting recuperation operated with the shift paddles, and brake recuperation (which ‘smoothly’ transitions deceleration between the engines and the brakes).
The e-tron’s speed can also be modulated using just one pedal, as is commonplace among electric cars. Using the shift paddles and triggering manual coasting recuperation mode, the e-tron can be made to go into its most aggressive energy recuperation setting, where deceleration is most noticeable. In that setting, Audi claims that “there is no need to use the brake pedal in this scenario.”
However, the regenerative braking will only brake the car at up to 0.3g of force. Should the driver demand more than 0.3g of deceleration, the car will use the brakes to slow the vehicle down using that electrohydraulic actuation system we mentioned earlier. A hydraulic piston in the brake module is capable of creating additional brake force for the recuperation of torque.
Additionally, this system is very quick to react: Just 150-milliseconds is needed between driver braking input and maximum brake pressure application, which means that in an emergency stop scenario, the e-tron’s braking distance is some 20% shorter than a comparable SUV with a conventional braking system.
The e-tron will actually decide what is the best way to slow the car down for you: It’ll make use of data received from its radar sensors & cameras, running it by navigation data, and then it’ll choose between mechanical braking or engine braking as the best way to decelerate that allows for optimal energy recuperation. Of course, the driver is kept on top of the e-tron’s energy flow throughout thanks to displays within the cockpit that display this information, allowing drivers to fully understand what their car is doing at any given time, and give them the ability to truly maximise the e-tron’s electric powertrain.
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