If an electric vehicle or plug-in hybrid crashes, how safe is it for passers-by to assist occupants?
Perhaps the greatest fear of most who are able to identify an electric vehicle (EV) or plug-in hybrid in the first place is whether parts of the car body have been electrified due to damaged cables.
This fear is understandable, as electricity supply from the batteries range from 120 to more than 400 volts. These voltages can cause serious injury.
Automotive engineers who design electrical powertrains are aware of the hazards posed by high-voltage electrical supply from the battery pack. The industry has defined a number of compliance standards for manufacturers, including power control strategy in a collision.
BMW, for instance, integrates an onboard controller called the Advanced Crash Safety Module (ACSM). A sophisticated microprocessor-controlled system evaluates the severity of a crash based on several parameters, and if warranted, triggers electro-mechanical switches which instantly trip to cut off supply from the batteries.
This system is designed with redundancy, so that if one component fails, other will kick in.
This eliminates any possibility of electricity running through the car body - even if power cables are compromised and come into contact with the frame.
Lithium-ion battery packs are also assembled in safety cells which are first put through computer simulations in a number of crash scenarios. EVs undergo crash tests to ensure they are resistant to power leakage.
In conclusion, it is safe to assist occupants in a crashed EV or plug-in hybrid.