EQ Session V: EQC safety: Quality by tradition

Passive safety milestones

• In 1959, Mercedes-Benz was the first manufacturer to introduce systematic crash testing and the use of dummies. In the 1950s, Mercedes-Benz created the first car with a rigid passenger cell and crumple zones as well. This was first implemented in series production in the Mercedes-Benz S-Class W 111 model series. In July 1981, the
  S-Class was the first car that offered the combination of driver airbag and front-passenger belt tensioner.

Active safety milestones

• The S-Class W 116 was the first production car to use an electronic four-wheel multi-channel anti-lock braking system – ABS for short – in 1978. In the mid-1990s, Mercedes-Benz introduced the Electronic Stability Program (ESP) as well as the world’s first Brake Assist system (BAS). In 2002, the brand presented the PRE-SAFE® preventive occupant protection system in the Mercedes Benz S-Class.

EQC safety

• The EQC (combined power consumption: 22.2 kWh/100 km; combined CO₂ emissions: 0 g/km, provisional figures)*, is at the forefront of both active and passive safety. One highlight is the latest generation of the industry-leading driving assistance system, which was first introduced in the S-Class. This comes with new features. For example, in a tailback, the lane guidance system keeps the vehicle off-centre to leave space for emergency services.
• The EQC’s vehicle structure has been adapted to suit the special requirements of the electrical components and battery. It is designed to achieve the high level of safety that Mercedes-Benz is known for. For example, in the EQC, a subframe surrounds the drive components located in the front section and supports this unit. As a result, crash kinematics are comparable to conventional Mercedes-Benz cars.
• The battery is placed in the floor of the vehicle and is surrounded by a robust frame with an integral crash structure. This means that additional deformation elements are installed between the frame and the battery. These can absorb forces during severe side impacts. A protection shield in the front area of the battery can protect it from foreign objects.
• In the event of an accident, the EQC has high-voltage safety architecture, including an overlapping protection concept with insulation, physical contact protection and high-voltage shutoff. The high-voltage system can also be shut down automatically when the crash sensor detects an impact. Depending on its severity, a distinction is made between a reversible and an irreversible cut-off.
• In the case of a reversible cut-off, which occurs in less severe accidents, it is possible to switch the high-voltage system back on if a prior insulation measurement detects no faults. This means that vehicles can still be driven.
• Only in the case of very severe accidents, where the vehicle can no longer be driven, the high-voltage system shuts down and cannot be reactivated without a repair. When shutting down, there is a provision to ensure that, within a few seconds, there is no critical residual voltage in the high-voltage system outside the battery.
• Even during the fast-charging process (DC charging), an additional impact sensor system that is integrated in the DC box monitors impacts. If it detects a collision with the vehicle, the charging process is automatically stopped.

Rescue Sticker and Rescue Assist App

• With a small but effective innovation, Mercedes-Benz has found a way to give rescue services the best possible support and a clear overview of the vehicle’s safety-related features. The Rescue Sticker provides a direct link to the vehicle’s rescue data sheet. Corresponding stickers are affixed to the charging flap and to the opposite B-pillar of the vehicle for this purpose. Following an accident, rescue services can scan the QR code with a smartphone or tablet PC for fast and reliable access to the rescue data sheet for the specific vehicle concerned. This makes rescue operations easier.
• Alongside the rescue data sheets, the Rescue Assist App for smartphones and tablets also has three-dimensional views of the vehicle – now also offline in case there is no mobile network available at the accident scene.

EQC battery safety and quality standards

• Our extremely high safety standards also apply to the battery and all its components.
• Safe battery housing is also crucial for one very important component of electric vehicles: the battery management system (BMS). The BMS covers a multitude of different tasks. It collects all relevant data on the battery cells, such as voltage, current and temperature. It stores them and communicates with other car components. To make sure the BMS is protected from potential hazards in case of an incident, it is placed in a crash-proof part of the battery housing.
• Intelligent thermal management is another major concern. Besides keeping the battery temperature within an optimal range, even cooling is also crucial. The EQC’s integral cooling concept consists of heat pump functions and two electric PTC block heaters. Fluid cooling for the entire battery system ensures an optimal operating temperature for the cell modules.
• When talking about high-performance battery systems, one of our main battery development goals is ensuring a high density of usable energy while ensuring all major aspects of safety.
• To make sure the batteries live up to Mercedes-Benz quality standards, they are extensively tested both on subcomponents and at the system level. This includes:
  • Performance and energy level at different temperatures
  • Behavior under various impact load scenarios
  • Safety testing (e.g. overcharging, penetration testing, short circuits)
  • Market-specific testing due to local regulations (e.g. GBT Standard China)
  • Service life testing (mechanical, thermal and chemical)
  • Interaction of drive components incl. preconditioning functions

*Figures for power consumption and CO₂ emissions are provisional and were determined by the German Technical Service corporation. The range figures are also provisional. EC type approval and conformity certification with official figures are not yet available. There may be differences between the stated figures and the official figures.