Features
27 Feb 20

How safe are (PH)EVs in the event of a crash?

We basically take the safety of our company cars for granted. But what about the high-voltage components of EVs and PHEVs in the event of a crash? Are occupants, emergency service workers and bystanders at risk?

Plug-in hybrids and electric vehicles are about to invade the European continent now that the 95g/km CO2 target is pushing OEMs to sell them in high volumes and corporates see them reach TCO parity with conventional cars.

Carmakers invest a lot in training their after sales staff to get familiar with the technical aspects of an electrified powertrain. Safety is the number one priority when working on a high-voltage system. With good reason: the voltage ranges from 200 to 800 volts – enough to deliver a lethal shock. By way of comparison: a regular car is fired up by a 12-volt battery.

Emergency workers, too, are well trained to handle accidents involving hybrid and electric vehicles. But do you know what to do and what to watch out for in the event of a severe crash? Unless you read the vehicle’s manual, you’re unlikely to know the answers.

Orange is the new red

Generally, the colour red indicates danger, but in the case of electrified vehicles, the high-voltage cables are painted in bright orange. That’s the first thing you should know. The second is that they are not dangerous to touch as such, but in the event of a crash, these cables could rupture and the copper wiring inside may get exposed.

That is why all electrified vehicles have crash sensors that automatically disconnect the battery from the vehicle’s electrical system. “Our electric high-voltage system is also designed as a free floating system, which means that neither of the electric polarities are in contact with the vehicle itself,” Volvo Cars told Fleet Europe.

Reassuring as that may be for the occupants and people trying to help, before touching the car, emergency workers must always check whether the system is ‘live’ or disabled. That is why they wear rubber gloves that can withstand 1,000 volts.

After verifying the car is safe to touch, the emergency services will do their job: stabilise the casualties and remove them from the wreck in the safest way possible.

Leaking fluids and fire

Next to the high-voltage system, there is of course the battery itself, which contains a flammable and corrosive electrolyte. Here too, batteries are designed to withstand crashes, from their casing all the way down to the cell level. Lithium-ion battery packs contain fail-safe circuitry that shuts down the battery when its voltage is outside the safe range.

The chances of a battery leaking or catching fire are very limited. If fire should occur nonetheless, electric and hybrid cars with lithium-ion drive batteries are at least at the same level of safety as regular vehicles, says Dekra. Still, contact with the battery after a crash should be avoided at all times – medical attention is required should you accidentally touch battery fluid.

What to do if you witness a severe crash?
  1. Call the emergency services.
  2. If possible, pull over and go to the crashed vehicle.
  3. Switch off the ignition if you can.
  4. Never touch orange cables in the car, nor any fluids. If you have been in contact with fluids, rinse profusely with water.
  5. Do not remove the injured occupants from the vehicle, but wait for the emergency services.
  6. Stay close to the people inside the wreck and talk to them reassuringly if they are conscious.
  7. In case of severe bleeding, use bandage or a piece of clean textile and apply pressure to the wound, unless it is a severe head injury.

 

Authored by: Dieter Quartier