Airbags

Airbags remain one of the most important passive safety systems in vehicles — including EVs. Thanks to advances in vehicle construction, battery-safety design, and sensor technology, modern EVs often feature more sophisticated airbag systems than internal combustion engine (ICE) vehicles.

How Airbags Work

Airbags, or Supplemental Restraint Systems (SRS), are fabric cushions that inflate instantly during a collision to reduce injury. Controlled by a central airbag control unit (ACU), they use data from sensors — including accelerometers, impact detectors, and seat occupancy sensors — to determine whether and how to deploy.

Deployment occurs in milliseconds and helps prevent occupants from striking hard surfaces inside the vehicle. In many EVs, airbag deployment is also linked to the automatic disconnection of high-voltage systems to prevent post-crash hazards such as electrical shock or fire.

Types and Locations of Airbags in EVs

Modern EVs feature multiple airbag types strategically placed for maximum protection:

Front Airbags: Located in the steering wheel and dashboard, protecting the driver and front-seat passenger in frontal collisions.

Side Airbags: Typically mounted in seats or doors, these protect the torso during side impacts.

Curtain Airbags: Integrated into the roof lining above the windows, curtain airbags deploy downward to protect occupants' heads during side impacts or rollovers.

Knee Airbags: Found beneath the dashboard to protect the driver’s and sometimes the front passenger’s knees and legs.

Rear Airbags: Increasingly available in premium EVs, these are installed to protect rear-seat occupants.

Thorax Airbags: Mounted in the B-pillars or seats to offer additional protection for the chest area during a side collision.

Airbag Design and EV-Specific Considerations

EVs differ structurally from ICE vehicles, with battery packs typically mounted under the floor. This has implications for crash dynamics and allows manufacturers to optimize airbag systems with:

• Improved Structural Integration: Reinforced occupant cells and battery protection zones work in concert with airbag systems.
• Adaptive Deployment Logic: Airbags may deploy differently depending on seatbelt usage, occupant size, position, and crash severity.
• Battery Isolation: Some EVs automatically disconnect the high-voltage battery when airbags deploy, reducing fire and shock risks.

Advanced Airbag Technologies

EVs often include more advanced or numerous airbags than traditional cars:

Multi-Stage Airbags: Capable of inflating at varying pressures depending on crash force, offering optimal protection without excessive force.

Adaptive Airbags: Use smart sensors to tailor deployment force and inflation volume, minimizing injury risks in low-speed impacts.

Occupant-Specific Adjustments: Some systems consider seating position, weight, and movement to adjust deployment strategy in real time.

Emerging Trends in EV Airbag Systems

EV design flexibility allows for innovative airbag solutions:

• More Airbags Per Vehicle: It’s common for EVs to have 8–10 airbag modules, including knee, curtain, thorax, and seatbelt-integrated airbags.
• Flexible Interior Protection: As EVs move toward autonomous driving, airbags are being developed to protect passengers in reclined or rotated seating positions.
• Integrated Safety Ecosystems: Airbags are increasingly part of a coordinated suite that includes seatbelt pretensioners, adaptive restraints, and crash-data analysis systems.

Limitations of Airbags

Airbags are crucial, but they have limitations:

• Not All Crashes Trigger Airbags: Minor collisions or certain angles of impact may not meet the deployment threshold.
• Structural Deformation Limits Protection: Airbags can't compensate for severe cabin intrusion.
• Battery Safety Depends on More Than Airbags: Isolation mechanisms, thermal protection, and crash sensor integration are also key in preventing post-collision risks.