Firefighters extinguish burning BMW i8 by dropping it into a giant tank of water
There was a lot of news regarding electric car fires lately. Given how new and complex some of the technologies underpinning these cars are it's no wonder things can get a bit desperate when something goes wrong.
Firefighters from Breda in the Netherlands had to make a pretty bold move when they were called in to a fire at a local BMW dealership, where a BMW i8 (Plug-In Electric Hybrid) started 'smoking'.
A rather brave dealership employee drove the car out of the building possibly saving the dealership from being damaged and making the job of first responders a fair bit easier. Once the firefighters arrived on scene they decided the best way to deal with the fire was to submerge the whole car in a large tank of water for the following 24 hours.
It's currently unknown what caused the BMW to catch on fire.
Seems extreme and wasteful? No, not really..
Tesla estimates it takes about 11,356 litres of water to extinguish one of its battery packs if it neds up on fire for some reason. That amount of water would keep a human thirst free for about 15-years. The water tank idea doesn't seem half bad now, does it?
More so Tesla in its online Emergency Response Guide states that the battery pack may take up to 24 hours to fully extinguish, as it may re-ignite several times, even hours after the initial fire.
Why EV fires are such a pain? A brief rundown...
This is largely because of the way electric car batteries are built. The Tesla Model S 85 kWh battery contains over 7,000 individual cells, each packed with highly flammable lithium. This is great for energy density but can be somewhat tricky once the battery gets damaged.
All the cells are separated by a firewall, this slows down spreading of any potential fires and gives occupants plenty of time to get out safely. However, this also means it's quite difficult to locate and extinguish any build ups of heat or sparking that can lead to a further chain reaction.
This leads to cases where the battery re-ignites hours after the initial fire is put out. Tesla recommends using thermal cameras to inspect damaged battery packs and to 'quarantine' the batteries for 48-hours after an incident.
*Bear in mind this is just a brief explanation, for a more in-depth and detailed insight into the subject, I'm afraid you are going to have engage the old google search and do some digging.