How Safe Are Electric Cars?

Are EVs as safe as other cars?

Yes, we have crash tested almost every new EV and been very impressed by both their active (the way they avoid accidents) and passive (how they behave in an accident) safety performance.

In fact, in many ways EVs are safer than conventionally powered cars due to the weight and location of the battery, they have a low centre of gravity that benefits their handling. We see less 'spinning out' in an accident.

Without an engine, EV occupants are more vulnerable or not?

An engine is very heavy , transmits crash energy and can enter the occupant space. Not having one is a good thing not a bad thing, because it enables the engineers to build safer, more progressively absorbent front-end structures.

With it's excessive weight, isn't an EV just like a battering ram?

A heavy car is always good, but it's important that in a crash it doesn't simply crash other vehicles-'aggressivity' – when a heavy car smashes up another with little damage to itself. Instead, it should dissipate the crash energy within itself using absorbent and collapsible structures. The absence of an engine allows engineers to design these in."

What about the battery – isn't that a big impact risk?

Our toughest test, the pole test designed to replicate a car spinning side-on into a tree or pole, would expose shortcomings in battery protection but car makers protect them with armoured cases and we've seen no intrusion.

Why some EVs score four , not (the maximum) five-star rating in Euro NCAP crash tests?

Models such as Peugeot 208 and Vauxhall Mokka have fewer ADAS systems than five-star cars which reflected in their lower purchase prices. Ideally we would love manufacturers to fit every last piece of ADAS to their cars but there's a cost implication. What is upsetting when car makers reduce a model's safety, like Renault did when it deleted the centre airbag from the Zoe. As a result, we awarded the car no stars at all.

Are EVs better than conventional cars in this respect?

Often they're actually better. They use the latest electrical architectures that can talk to the driver-assistance systems (ADAS).They have a domain controller that is a bit like a computer motherboard, which controls the ADAS and can be updated.

Why Tesla Model S, is no longer rated by Euro NCAP?

It's rating has expired, it was don more than 6 years ago. In every five years, we have change in our test protocols, so our older ratings are no longer reliable.

Battery fire in crash tests?

From the accident data we know that there are very few battery fires involving electric vehicles. Automatic power cut-offs, battery isolation systems, pyro fuses that sever cables and blades that do the same thing – all these reduce the incidence of battery fires following a collision. However, it's when they're involved in a fire that they can turn dangerous, with cells catching alight and causing thermal runaway. This can be very difficult to extinguish.

So EVs are dangerous after all?

Battery fires are dangerous for those trying to put them out. After active/passive safety comes what we call 'tertiary safety' – dealing with the consequences of a crash. We expect car makers to provide data sheets explaining exactly what rescue services are dealing with and the location of cut lines so they know how to break in and free somebody quickly and confidently.

So we have seen battery fires after accidents but ironically, the battery case is so strong that it has been impossible for the rescue services to determine the state of the battery. Car makers must consider ways to provide cell integrity and battery state information that rescuers can quickly refer to