A residential neighborhood in China suffered a devastating fire caused by an electric bicycle, resulting in a significant loss of life. This has sparked concerns about the safety of batteries used in electric bicycles and cars.
Around 4 a.m. on Feb. 23, a fire broke out in a 34-story building in Nanjing, the capital of China’s Jiangsu Province. Online videos showed thick smoke and flames billowing from the building, spreading across several floors.
The building on fire was a residential neighborhood in the local Yuhuatai District called “Mingshang Xiyuan.” It wasn’t until daylight that the fire was extinguished, but the exterior walls still bore charred marks.
On Feb. 24, the local authorities reported that the fire incident had resulted in 15 fatalities and 44 hospitalizations, including one in critical condition and another in serious condition.
Electric Bicycle Fires Not Uncommon
Fires caused by electric bicycles are not an occasional occurrence in China. According to statistics from the National Fire and Rescue Bureau of China, there were 21,000 reported cases of electric bicycle fires nationwide in 2023, an increase of 17.4 percent from 2022. In 2022, there were 18,000 cases, a year-on-year growth of 23.4 percent.The National Fire and Rescue Bureau also pointed out that since many electric bicycle fires did not ignite surrounding objects and most people involved did not report them, the actual number is likely higher than reported.
Statistics show that 80 percent of electric bicycle fires occur when the device is charging. Despite China’s implementation of the “Fire Safety Management Regulations for High-rise Civil Buildings” in August 2021, which explicitly prohibits parking or charging electric bicycles in public hallways, evacuation corridors, stairwells, or safety exits of high-rise civil buildings, many still bring electric bicycles or batteries into buildings to be charged. The residential neighborhood where the fire broke out is a case in point.
Why Electric Bicycles are Prone to Fire
Regarding why electric bicycles are prone to fire, Xiang Guanyu, a station chief of the Wuhan Fire Rescue Brigade, told local media that there are three main reasons:1. Overcharging, which can cause batteries to overheat, swell, or even explode
2. Aging wiring. Prolonged use of electric bicycles can lead to aging and loosening internal wiring, resulting in leakage, poor contact, or short circuits.
3. Improper use of chargers, such as mixed use of charging equipment for different brands of electric bicycles, which can damage batteries. Chargers must match the battery model.
Chen Guoliang, director of safety at Lan Tu Automotive in Wuhan, added that if batteries are subjected to external force or self-modifications, resulting in abnormalities or leakage, it can also cause fires and explosions. In addition, the unauthorized connection of electric wires poses significant safety hazards, as household chargers and sockets are not designed for continuous high-current charging and can easily overload, leading to fires.
Poor-quality batteries are also a significant factor in fires. According to a report by China’s State Administration for Market Regulation released last year, the failure rate of electric bicycle batteries reached as high as 21 percent.
Furthermore, the declining use of safer lead-acid batteries and the increasing dominance of easily flammable and explosive lithium batteries are related to official regulations.
Lead-acid batteries have long dominated the Chinese electric bicycle market. They are cheap and contain sulfuric acid as the electrolyte, making them less prone to self-ignition and explosion. However, they are heavy, have limited capacity, and have a shorter lifespan, generally lasting up to 400 deep charge and discharge cycles.
In 2018, China’s State Administration for Market Regulation introduced the “national standard” for electric bicycles, stipulating that the maximum design speed of electric bicycles should not exceed 25 kilometers (15.5 miles) per hour, the nominal voltage of batteries should not exceed 48 volts, and the total weight of the vehicle (including the battery) should not exceed 55 kilograms (121 lbs).
Safety Concerns About Electric Vehicle Batteries
The Nanjing fire reminded the public of electric vehicles, known as new energy vehicles, which the Chinese authorities have vigorously promoted for years.The current mainstream types of new energy vehicles’ power batteries include lithium iron phosphate and ternary lithium batteries. Both are lithium batteries.
Although less visible in the media, the number of fires involving new energy vehicles is also significant. According to statistics from emergency management departments, in the first quarter of 2023 alone, the self-ignition rate of new energy vehicles increased by 32 percent, with an average of eight new energy vehicles catching fire (including self-ignition) daily.
At the China Electric Vehicle Hundred People Conference in Beijing in April 2023, Sun Shigang, an academician of the Chinese Academy of Sciences, stated that lithium-ion batteries face several major challenges, including frequent safety accidents. He revealed that there were about 3,000 cases of new energy vehicle fires in China in 2021.
