The individual cells themselves are surrounded by advanced phase-change materials that help absorb heat and reduce the risk of nearby cells overheating.
With such high voltage electrical systems, EVs also require special measures to ensure the occupants and attending emergency services aren’t shocked in the aftermath of an accident. Many electric cars operate at 400 volts, while Porsche was the first to launch an 800 volt set-up. At these sorts of voltages any contact with damaged cabling could prove life-threatening.
Fortunately, EVs have safety systems that automatically isolate the battery in the event of a crash. When the car’s various sensors determine a collision has taken place, special pyro-fuses are fired that sever the high voltage cables, effectively disconnecting all the power. German automotive specialist Bosch has also developed a system that drives a small wedge into the cable when the airbag is triggered.
Electric car noise emitter
Of course it’s not just the occupants of EVs that have concerns about safety – there are also many pedestrians and cyclists that are worried. We’re all told to ‘stop, look and listen’ when crossing the road, and it’s the last of these actions that’s trickiest to achieve with near silent electric cars. This is particularly true in urban areas, where speeds aren’t high enough for the usual tyre roar to be a giveaway. In fact, research carried out in 2015 suggested that EVs were 40% more likely to be involved in accidents with pedestrians.
However, as of the 1 July 2019 it became a legal requirement for all new electric vehicles to be fitted with an electronic noise emitter. Most cars have two devices, usually mounted behind the front and rear bumpers, that generate sound at a frequency that’s similar to an internal combustion engine at a similar speed. It’s particularly noticeable when parking, emitting a low whine when the car is manoeuvering.
Can you charge an electric car in the rain?