With the first electric vehicles hitting the road, some practical issues have become apparent: how do you deal with electric vehicles in accidents? What do emergency responders need to consider when rescuing people from a wrecked EV? Car manufacturers and rescue services start organising dedicated training courses.

Every vehicle involved in an accident poses safety risks: the voltage battery pack of an electric vehicle can in this case be just as dangerous as escaping fuel from a combustion engine that might ignite. Emergency responders have developed standard procedures for approaching accident-damaged conventional cars, knowing very well where danger can stem from and where to cut into the car body if need be.

The technical construction and internal arrangement of electric vehicles being quite particular, rescue teams need special training in order to understand how to safely approach these vehicles and how to contain or mitigate potential dangers.

EV training for rescue teams

Car manufacturers with EVs in the pipeline, such as General Motors, Mitsubishi and Nissan, and associations such as the National Alternative Fuels Training Consortium (NAFTC) in the U.S. for example, are therefore running a series of training courses to educate police officers, firefighters, paramedics, and other rescue staff on the essential skills of dealing safely with electric cars. These courses start off with basics such as teaching rescue teams to always first verify that the ignition is OFF (which in an EV is not as evident as in a conventional car), to more advanced knowledge such as how to remove the battery pack or where to cut through the car body. The car manufacturers make also sure to provide all essential technical information to rescue services in the markets the car model is going to be marketed in.

Rescue services themselves are conscious of the array of new operating conditions accompanying the introduction of electric vehicles. The U.S. National Fire Protection Association (NFPA) has therefore launched the U.S. Emergency Responder Safety Training for Advanced Electric Drive Vehicles Project, which will develop and implement an emergency response training program focused on advanced electric vehicles, including plug-in hybrid EVs, EVs, and fuel cell vehicles. The three-year project, funded by a $4.4 million grant from the U.S. Department of Energy (DOE), will develop a website that will include training programs, simulations, and videos to complete the classroom-training courses.

NFPA and the Society of Automotive Engineers (SAE) will also organise a U.S. safety summit on the safe implementation of electric vehicles in October this year.

High voltage: fire and electrocution risk

Electric vehicles operate at very high voltages. Numerous safety features are installed to assure fuel cut-offs (in plug-in hybrid electric vehicles (PHEVs) that have an engine for extended range) and battery disconnects (in PHEVs and full electric vehicles (EVs)). However no safety system is infallible.

An electric shock caused by an accident-damaged EV could kill an imprudent approacher. Sparks from the EV's electric system have enough voltage to ignite escaped fuel or even set battery or car on fire by itself. First responders are therefore taught how to verify if the cars' high voltage system has been switched off and, in case it has not, how to shut it down manually. They are shown the locations and safe removal of mechanical battery disconnect service switches designed to split the battery pack up in such a way that electrical shock risks are eliminated.

Different internal arrangement: where to cut through safely?

Thanks to their familiarity with conventional cars, rescue teams can generally tell where the engine and the fuel tank are located and where to cut safely through the car body in order to save caged accident victims. The internal arrangement of electric vehicles, however, somewhat differs.

General Motor's 2011 Volt extended range electric car, for example, houses both a T-shape centrally-mounted battery pack as well as a gasoline tank and gasoline engine for extended range operation. This means that the Volt bears both the risks of an electric car as well as a gasoline car for the rescue teams. From outside, it is not evident where they are located.

For this reason, the rescue teams are specifically trained by car manufacturers and associations how to locate the best places to cut through the EVs' thickened chassis and door pillars in order to rescue trapped occupants as well as being able to identify high voltage power cables in the transmission and power systems of the extended range electric car.

Basic safety features: clear marking of batteries and high voltage lines

Accidents often leave cars upside down and can sometimes require unique approaches to extrication. Under these circumstances, it is of utmost importance for rescue teams to have high voltage lines and batteries clearly marked - no matter from which direction the battery pack is approached, which in an accident could very well be from a direction that under normal conditions is inaccessible.

Standards for high voltage cabling in EVs

The Society of Automotive Engineers (SAE) is working on an international standard to define high voltage cabling in EVs. So far, most manufactured EVs clad high voltage cables with orange sheathing or use orange cabling to indicate high voltage. However, this is not a standard yet as some models also use blue.

With electric vehicles entering real life, some more of these practical implications might become apparent. So let's get prepared.