BMW announced the newest additions to the BMW i brand, the i4 eDrive40 and i4 M50 models. The i4 M50 is the first fully-electric performance model to come from BMW M GmbH. The i4 blends the functionality and space of the gran coupe design with the instantaneous power delivery of BMW’s latest 5th generation eDrive. Class-leading driving dynamics and long-distance comfort, elegant design, uncompromising workmanship, cutting-edge user-vehicle interface and advanced infotainment and driving assistance technologies all combine to deliver a zero-emissions BMW worthy of the Ultimate Driving Machine moniker. BMW Group has been producing battery modules and high-voltage batteries since 2013 and this in-house experience shows, with the latest generation of batteries, found in the i4, having a maximum DC fast charging capacity of up to 200 kW and AC Level 2 charging of up to 11 kW. Power is provided by BMW’s latest 5th generation eDrive technology which combines the electric motors, power electronics, charging system and high-voltage battery. The electric motor, power electronics and transmission share one compact housing while the high-voltage battery measures only 4.3-inches in height and is mounted low in the floor of the new i4 for improved vehicle agility.
The electric motors for the BMW i4 are made without the use of rare earth materials, allowing the BMW Group to not be reliant on their availability. The proportion of secondary aluminum used in the i4 helps to make manufacturing more sustainable. Targeted use of recycling methods for this high-grade lightweight metal can lead to a substantial reduction in the energy-intensive use of primary aluminum, which also generates high levels of CO2 emissions when conventional manufacturing techniques are employed. Besides this, recycled plastics are used in many i4 components. The high-voltage NMC-811 batteries in the BMW i4 contain less than 10 percent cobalt content. In addition, the BMW Group procures the required cobalt for its battery cell production itself and then makes it available to the battery cell suppliers. The lithium required for battery cell production is likewise obtained under transparent conditions that are monitored by the BMW Group. The BMW Group sources the lithium used in the high-voltage battery pack on board the BMW i4 from hard-rock deposits in Australia and passes it on to the battery cell makers. The company can therefore ensure that environmental and sustainability standards are observed during the extraction and processing of cobalt and lithium and that there are no violations of human rights.
Thanks to the battery module, the i4’s center of gravity is 1.3-inches (BMW i4 M50) or 2.1-inches (BMW i4 eDrive40) lower than on a 3-Series Sedan. The ingredients which make up the experience of driving a BMW include instantaneous power delivery, excellent traction and directional stability, neutral steering behaviour, precisely controllable handling even under maximum lateral acceleration, superb stopping power and an excellent balance between sportiness and ride comfort in everyday driving and on long trips alike. The new BMW i4 delivers all these attributes with zero tailpipe emissions. The 5th generation eDrive technology offers instant torque-on-demand while the location of the high-voltage battery low in the vehicle’s floor reduces center of gravity for improved handling. The rigid body structure and sophisticated chassis design impart superb agility, especially for the new i4 M50, the first purely electric performance model from BMW M GmbH.The development teams at the BMW Group and BMW M GmbH harnessed their immense expertise, acquired over many decades of work, for the i4’s fine-tuning. An intensive program of testing was carried out at BMW Group’s test sites in Miramas in southern France and Arjeplog in the north of Sweden to make sure that motor output, power transmission, chassis set-up and body attributes created a compelling driving package.
The fully variable system can choose the exact needed split, from highly efficient pure rear-wheel drive to all-wheel-drive for maximum traction. Normally, drive power is relayed solely to the i4 M50’s rear wheels to increase its efficiency and range. At higher levels of lateral acceleration or in response to wheel slip, the motor acting on the front wheels assumes the required drive power delivery to optimize driving dynamics and directional stability. With an electric motor at both ends, the new i4 M50 features an electric all-wheel drive system which increases traction in all road conditions, and which can optimize traction and handling stability by adjusting the drive torque, without the need for traction control intervention. The BMW-developed near-actuator wheel slip limitation, which in combination with the electric all-wheel drive, enables the car to maintain optimum traction in a straight line. Specially configured for the instantaneous power delivery of electric motors, this traction control system is integrated into the motor management. This eliminates the long signal paths to the control unit for the DSC (Dynamic Stability Control), meaning that the corrective inputs are applied up to ten times faster than in conventional systems.
The BMW i4 M50 is powered by a front 255 hp electric motor and a rear 308 hp motor, which together put a combined maximum output of 536 hp. The single rear electric motor in the BMW i4 eDrive40 delivers 335 hp. Power and torque is transmitted to the respective drive axle via a one-speed transmission which is contained in the same compact housing as the electric motor. The electric motors developed in-house by the BMW Group have an efficiency factor of 93 percent, bettering the efficiency figures achieved by current combustion engines of less than 40 percent. The BMW i4 features one electrically excited synchronous motor driving the rear axle on the i4 eDrive40 and two motors, driving both the front and rear axles, on the i4 M50. The drive system’s high efficiency and cutting-edge NMC-811 battery cell technology give the car a long operating range and exceptional everyday usability. The extremely powerful charging technology is capable of 200 kW charging capacity for high-power DC charging. The excitation of the rotor in the BMW i4 motors is not induced by fixed permanent magnets, but the feed-in of electric energy. This allows the use of critical rare earth metals (required for magnetic components) to be avoided altogether in the manufacture of the rotor.
