On fire hazard from e-vehicles: Read the smoke signals

News: Safety concerns have emerged after several recent incidents in which e-scooters have caught fire, causing panic and loss of life. While the government has ordered an enquiry, the authorities must review and reorder the road-safety ecosystem.

What are the reasons behind fire incidents?

Harsh summer driving conditions: The scooter fires could have been caused by the unsuitability of imported lithium-ion battery packs for summer driving conditions.

– India is hotter in summer than most places where e-vehicles are popular, and the standard battery pack designed for North America or China is not tropicalised to withstand Indian summers.

Stressful driving environment: India is also a stressful driving environment, necessitating sudden acceleration/braking, which means a greater load on the battery pack, which therefore gets hotter.

What are some issues with battery packs used in e-vehicles (EVs)?

Spontaneous combustion: A battery pack heated beyond a certain point can spontaneously combust.

– This can happen if a hot pack is recharged without a cooling-off period.

– It can happen long after a crash because of internal short-circuits, which are invisible to inspection.

– Also, a battery pack can reignite —due to invisible internal reactions — spontaneously 24 hours after the fire has been apparently extinguished.

Battery fires burn hotter than petrol fires, and emit a combination of highly toxic smoke and flammable fumes, which can inflame nearby vehicles and structures.

How are fire hazards caused by EVs and Internal Combustion Engines different from each other?

An ICE faces the danger of an electrical short circuit setting off an explosion of the fuel tank, as well as the danger of the fuel line, or the tank being ruptured in a crash, leading to flammable liquid or fumes leakages.

In an e-vehicle crash, the delayed action factor means that the vehicle and/or its battery pack must then be isolated and observed.

– If there is a fire, it cannot be tackled easily. The foam used to smother petrol fires is ineffective.

– The advice is to detach the battery pack if possible, and to direct jets of cool water at it, until it cools, and then it must be kept under observation.

What are the steps that need to be taken?

Packs designed to operate in cooler, less stressful driving conditions must be tested more stringently and, maybe, modified for India. If other technical factors are involved, those must be identified and addressed.

By the Govt

–The government may have to set new standards for battery packs, and warn users to wait for a cool-down before recharging.

– As the number of e-vehicles in service rises, the fire brigade and the police will need to be retrained, and, maybe, issued new equipment. This is because a fire caused by ICE and EV is different in nature and need to tackled accordingly. 

– In addition, the government must launch an outreach campaign to reassure citizens about the safety of this new class of green vehicles.

What is the way forward?

As green vehicles, including cars and buses, are adopted in larger volumes, the fire safety factor will acquire greater importance. Fire departments and police safety protocols must be updated to deal with them.

Source: This post is based on the article “Read the smoke signals” published in the Business Standard on 8th Apr 22.