EV

Safety questions vex battery-powered cars

By Hu Yumo  14:56 UTC+8, 2020-08-27       

New technology and startups always have hiccups, and not even the development of electric cars is immune.

A series of fires in China this year related to new-energy cars has raised anew public concerns about the safety of such vehicles.

On August 11, a vehicle from Chinese electric car startup Xpeng Motors caught fire in Guangzhou. Xpeng claimed that the blaze was caused by damage to the vehicle battery pack after its bottom had been knocked.

It was the latest in a string of electric-car fires this year in China, adding to a long list of such incidents around the world in the last five years.

After hearing about the most recent fire, many people in China began searching for videos of other similar fires, explosions or other accidents on the social media platform Weibo and discussed their findings with friends and relatives.

Electric vehicles, touted as an Earth-saver and pollution solution, have had to contend with a range of public concerns since they jumped from concept to production. People worried about the availability of charging stations. People worried about how far a car could go on one battery charge. They worried about the life of the batteries and the cost of replacement. And now the continuing worry about the safety of the batteries themselves.

My friend Jiang Jia, who works for state-owned company Shanghai Construction Group, told me she was planning to buy an upmarket electric vehicle next month, citing government subsidies for green cars. But after seeing the recent reports of fire incidents, she is reconsidering that decision.

“Safety is always the first priority for me,” she said. “If the safety of a driver and passengers cannot be guaranteed, I will not buy an electric vehicle and will choose a gasoline vehicle instead.”

China had about 20 electric-vehicle fires in the first half of this year. The incidence of such accidents accelerated in the second quarter, as life resumed some semblance of normal after the height of the coronavirus outbreak.Gaogong Industry Research Co

According to Gaogong Industry Research Co, China had about 20 electric-vehicle fires in the first half of this year. The incidence of such accidents accelerated in the second quarter, as life resumed some semblance of normal after the height of the coronavirus outbreak.

According to the research firm, there were nine electric-vehicle fires in June alone in China. That leaves the public asking: Can hot summer temperatures and exposure to sunshine cause car batteries to catch fire?

This is not the first year that fires have dogged electric cars.They have been logged for years around the world.

.Safety questions vex battery-powered carsT

In April last year, a Tesla Model S exploded in a Shanghai parking lot. No one was injured. An Audi and a Lexus were also damaged.

Last year, a Tesla Model S exploded in a Shanghai parking lot, one of about nine fires related to Tesla cars globally in 2019.

As a result, the US electric carmaker, which now has a major production center in suburban Shanghai, issued a software update for its vehicles to provide greater protection for the batteries and to improve their longevity.

Global fire-related incidents have also been reported in past years for plug-in vehicles manufactured by major automakers like Mitsubishi, Toyota, Chrysler and Chevrolet.

Shanghai-based NIO, a domestic automaker specializing in the design and development of electric, self-driving vehicles, recalled 4,803 of its ES8 electric vehicles in June 2019 due to battery safety concerns after a series of fires. The recall affected nearly 30 percent of all vehicles the company had delivered to buyers.

Batteries account for about 60 percent of fires in plug-in vehicles. Collisions were responsible for about 20 percent, according to China Automotive Technology & Research Center Co. Other main causes were mechanical damage, water immersion and thermal runaway.China Automotive Technology & Research Center Co

Batteries account for about 60 percent of fires in plug-in vehicles. Collisions were responsible for about 20 percent, according to China Automotive Technology & Research Center Co.

The remaining causes were mechanical damage, water immersion and thermal runaway. The latter situation, related to lithium-ion batteries, results when an excessive current runs through a battery, causing it to heat up. As it gets hotter, it will accept more current and heat up even further.

Changing batteries

As one solution to the problem, most electric-car manufacturers have switched to nickel-metal hydride batteries that are less prone to thermal runaway.

Wang Binggang, head of the national new-energy vehicle innovation project, said that “safety issues of new-energy vehicles cover their entire life cycle, including design and development stages, and manufacturing and application processes. If one step is not well controlled, he said, fire risks can rise.

China is a global leader in production and promotion of electric vehicles, with 486,000 units sold in the first seven months of this year. according to the China Association of Automobile Manufacturers. In July, sales of new-energy vehicles ended 12 straight months of decline, with a 19 percent jump to 98,000 units.

The country’s sales target for green vehicles is 7 million, or about a fifth of all car sales.

The electric car market has drawn in many domestic startups that started to deliver mass-produced vehicles to buyers in 2018. Startups such as NIO and Xpeng Motors delivered a combined 44,000 units in the first half, up 45 percent from a year earlier.

As sales of new-energy cars have increased, more problems have surfaced. Industry analysts blamed them on the startups’ lack of experience in product design and quality-control management.

In May, China has issued three national safety standards for electric vehicles and their batteries, which will come into effect in January. One of the standards relates to electric vehicles in general, another focuses on electric buses and the third encompasses batteries that power the vehicles.

The Ministry of Industry and Information Technology said that national standards are to protect vehicle buyers and guarantee the industry’s ongoing sustainability.

Among other aspects, the requirements stipulate that battery systems must warn drivers of any imminent fire threat if a battery is damaged. There are also specific requirements for waterproofing, insulation and systems control. The new standards also outline vehicle-testing methods in more detail.

“The safety of new-energy vehicles can be guaranteed through system design and the government’s ever-increasing standards,” said Zhao Lijin, director of technical standards department at the Chinese Society of Automotive Engineers.

Source: SHINE  

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