BMW ActiveE Concept, 2010
Introducing the BMW ActiveE Concept, the latest electric vehicle project under BMW Group's initiative to produce vehicles that explore solutions to minimize environmental impacts while preserving the kinetic driving experience for which BMW has long been known. The BMW ActiveE Concept follows the all-electric MINI E as the second large-scale electric vehicle test program to be conducted in the hands of interested customers.
The BMW Group presents yet another milestone along the way to achieving CO2-free mobility. The BMW ActiveE Concept provides a taste of a purely electrically powered BMW. Focused on the requirements of practical use, the study is based on the BMW 1-Series Coupe and embodies the outstanding agility and characteristic driving pleasure of the BMW 1-Series for the first time as part of an emissions-free drive concept.
With the world premiere of the BMW ActiveE Concept at the 2010 North American International Auto Show (NAIAS) in Detroit, the BMW Group is highlighting the continuation of its research and development activities in the field of electro-mobility. The field tests with the MINI E as part of project i in the US and Europe have already provided important insights into the demands required of future production electric vehicles. As a second step, project i has begun development of a second trial fleet of electric vehicles based on the BMW ActiveE Concept. These vehicles are likewise intended for everyday use by private and select fleet customers as part of a large-scale field test. The insights gathered in the process will be fed into the development of an electrically powered serial production vehicle which the BMW Group will put on the market under a sub-brand of BMW in the first half of the next decade.
The BMW ActiveE Concept has allowed BMW to explore new vehicle packaging solutions and components which will be crucial to the success of the Megacity Vehicle. The intelligent integration of drive components within the existing vehicle package of the BMW 1-Series Coupe offers the opportunity to provide four full-size seats and a luggage compartment with a capacity of 200 litres / 7 cu ft. The motor, specially developed for the model and located in the rear axle, delivers 125 kW/170 hp and provides maximum torque of 250 Nm / 184 lb-ft. It accelerates the vehicle in less than 9 seconds from zero to 100 km/h (0-60 mph in approx. 8.5 seconds).
The electric drive system draws its energy from new, advanced lithium-ion battery pack developed jointly by BMW and the co-operation partner SB LiMotive especially for the BMW ActiveE Concept. They enable a range of approx. 160 kilometres (100 miles) in everyday use. An intelligent battery management system helps achieve this range largely independently of external climatic conditions. Additionally, the charging period required for the lithium-ion batteries is very short. On the European power grid, the battery pack can be fully charged in just 3 hours at a wall box with a current of 50 ampere at 230/240 volts. In North America, using a high-current (32 ampere continuous) residential wall box, the charge time is about 4.5 hours.
Innovative technology for sheer driving pleasure without CO2 emissions.
The BMW ActiveE Concept embodies a whole new dimension of purely electrically powered mobility. The dynamic potential and high torque of the drive system, along with the rear-wheel drive which is a hallmark of the brand, guarantees the characteristic sheer driving pleasure which is typical of BMW - but without any CO2 emissions. An impressive range of functions and a high level of suitability for everyday use are additional features of this concept, which defines electro-mobility in true BMW style.
The BMW Group attaches key importance to electro-mobility in the development of future-oriented vehicle concepts and drive systems as part of its EfficientDynamics strategy. In the medium term, BMW Group is developing innovative vehicle concepts for emissions-free mobility in urban areas. This so-called Megacity Vehicle will also be offered with an electrical drivetrain. The BMW ActiveE Concept represents a further step towards the realization of this concept. Components of the vehicle may be developed further for later integration into the Megacity Vehicle.
Electric drive: emissions-free, powerful and compact.
The BMW ActiveE Concept offers the prospect of characteristic BMW driving pleasure without exhaust emissions. The requirements for electro-mobility with characteristic BMW properties are being created based on ongoing development in the powertrain. The latest outcome is a new synchronous electric motor tailored to the BMW ActiveE Concept. It offers a high level of efficiency, power delivery, and compact construction.
The maximum output of the new electric drive is 125 kW/170 hp. The maximum torque of 250 Nm / 184 lb-ft is available from a standstill as is typical for electric motors. The torque remains available over an unusually broad load range. Unlike asynchronous electric motors, the new power unit provides a relatively high level of torque even at higher engine speeds and road speeds; at increased load the torque is not reduced abruptly but decreases gradually. The torque curve at higher engine speeds is therefore much more similar to the pattern familiar from combustion engines.
The vehicle concept and drive system provide the agility and dynamic acceleration performance which are characteristic of the BMW 1-Series Coupe. Based on realistic simulations, a figure of less than 9 seconds was measured for the sprint from zero to 100 km/h (0-60 miles in 8.5 seconds), with the 60 km/h mark being reached after less than
4.5 seconds. The maximum speed of the vehicle is electronically limited at around 145 km/h or 90 mph.
The innovative character of the electric drive is also reflected in the optimized ratio between engine output and space requirements: the compact power package is fully integrated in the rear axle of the BMW ActiveE Concept. Here the drive system occupies the space required in conventional vehicles by the differential, whose function is integrated in the drive system.
Recuperation of energy increases range.
In the purely electric powered BMW, the driver may control deceleration as well as acceleration through the movement of the accelerator pedal. As soon as the driver's foot is removed from the accelerator, the electric motor performs the function of a generator, converting the vehicle's kinetic energy into electric power and storing it in the battery pack. Intensive use of this so-called energy recuperation process by the motor increases the range by up to 20%.
At the same time, a brake torque is created which results in effective deceleration of the vehicle. This response enables a very comfortable driving style, especially at medium and constantly varying speeds. In urban traffic, some 75 percent of all deceleration manoeuvres are initiated without the need for the brake pedal. During Brake Energy Regeneration function, the vehicle's brake lights are illuminated.
This brake effect acts on the rear wheels only. When the driver requires a higher level of deceleration, stepping on the brake pedal engages the conventional hydraulic braking system. If an emergency braking maneuver is required during braking, the Dynamic Stability Control (DSC) system applies selective braking and motor management measures to ensure that safe braking is always guaranteed.
The brake system is fitted with an electric vacuum pump which is activated on demand. Along with the Electric Power Steering (EPS) familiar from the production models of the BMW 1-Series, these features contribute to an increase in the overall efficiency of the vehicle.
Innovative lithium-ion battery pack with its own liquid cooling.
The lithium-ion battery pack specially developed for this vehicle supplies energy to the motor and all other functions of the BMW ActiveE Concept. The high-voltage battery units offer a particularly high storage capacity and durability. For the first time, storage cells are used which were developed especially for use in automobiles by the BMW Group in collaboration with the co-operation partner SB LiMotive. Powerful battery cells are key when it comes to designing production vehicles with electric drive. Through the collaboration of the BMW Group with a joint venture of the companies Bosch and Samsung SDI [SB LiMotive], leading expertise in the area of battery technology and electro-mobility has been brought together. The aim is to use the best available technology in the area of energy storage as part of the development of the Megacity Vehicle.
For some time now, lithium-ion technology has demonstrated its particularly high storage capacity and deep-cycle resistance - for example in mobile phones and laptops. The technological expertise of SB LiMotive ensures that these properties are retained even under the special conditions of use in an automobile and the relevant demands in terms of durability, endurance and safety.
The lithium-ion batteries of the BMW ActiveE Concept have their own liquid cooling system and intelligent battery management system, which are key elements in increasing both the storage capacity and the durability of the battery cells. These systems also ensure that the long range can be maintained largely independent of external climatic conditions. The high storage capacity is the decisive factor in achieving as long a range as possible. The storage system developed for the BMW ActiveE Concept enables a real-world range of about 160 km / 100 miles on a single charge, depending on conditions (FTP72 cycle range is calculated to be 240 km / 150 miles in simulation).
Modular structure, compact construction, space-saving integration.
Another special feature of the battery pack is its outstanding compactness, despite its output and capacity. The arrangement of battery cells, grouped into several modules, is ideal in terms of packaging, functionality and vehicle balance. The battery pack is located where a combustion engine and fuel tank would normally be located. The largest portion of the battery pack in the BMW ActiveE Concept is located where the conventional propshaft and fuel tank would be in the lower section of the vehicle. In addition, a portion of the battery pack is located where the combustion engine would normally reside. Using intelligent lightweight design and the highly-efficient lithium-ion battery cells, vehicle curb weight is limited to about 1800 kg / 3900 lbs.
Characteristic BMW driving experience, space of a BMW 1-Series Coupe.
The positioning of the battery pack shifts the vehicle's center of gravity downwards. Also, the battery cell layout within the vehicle preserves the near 50-50 weight distribution characteristic of BMW vehicles. In this respect, the BMW ActiveE Concept offers ideal conditions for driving experience characterized by a high level of agility.
In terms of the space available in the interior, the BMW ActiveE Concept has no disadvantage compared to the BMW 1-Series Coupe with conventional combustion engine. It offers four full-size seats with the same measures of head, leg and shoulder space.
The optimum positioning of the power electronics above the motor integrated in the rear axle, for reasons of safety and functionality, results in a reduction of trunk capacity. Nonetheless, the BMW ActiveE Concept still has a luggage compartment which provides considerable versatility in everyday use. With a volume of approx. 200 litres / 7 cu ft, it even exceeds the trunk capacity of the BMW 1-Series Convertible with an open top and can hold two 46-inch golf bags, for example.
