Around 3:30 a.m. on June 23, flames lit up surrounding high-rises in Chengdu, Sichuan province—forming “mushroom clouds” of fumes hovering in the air, according to news reports. Allegedly started by a single electric bike which ignited around 200 bikes being stored in a communal shed, the conflagration was finally put out by local firefighters after half an hour, fortunately with no casualties.

However, five residents in another Chengdu community had not been so lucky six weeks earlier: Flames and smoke engulfed the elevator of their housing compound in two seconds, when the electric bike a resident had carried in exploded. All of them were hospitalized, with 75 percent of the skin of one woman burned, and 40 percent of the skin of the 5-month-old granddaughter in her arms.

Such tragedies have been an almost daily occurrence in China for the last decade. According to a report released by the Fire and Rescue Department (FRD) of the Ministry of Emergency Management (MEM) in 2018, 10,000 reported fires were caused by electric bikes between 2013 and 2017, making over 2,000 cases per year, or five cases per day.

One major safety risk lies in improper charging of electric bikes, sometimes with a mismatched adapter or unstable power supply that can result in a short circuit. As indicated in the FRD’s report, 80 percent of the 10,000 fires had been caused by bikes being charged up, mostly during the night. Overnight charging may allow bikes to be fresh for the following day’s rides, but can lead to overcharging.

Bike owners often charge their vehicles indoors for the sake of convenience, and because of a lack of public facilities for bike-charging and battery-sharing. Around three years ago for instance, only half of the 13,000 residential communities in Shanghai were equipped with parking and charging spaces, according to The Paper.

Modified batteries are another smoking gun. Many consumers (especially courier drivers and others who work in private logistics), dissatisfied with the average mileage for electric bikes of 30 to 40 kilometers, have repair shops replace their battery with double or even triple storage capacities, often lacking the relevant safety mechanisms.

Moreover, national technical standards favor lithium batteries—lighter and with higher capacity than traditional lead batteries, but much more flammable. Standards for these batteries are lax, leaving out tests that show the battery’s limits, like piercing or submerging in water.

In the face of rising incidents relevant public and private bodies have strengthened protection efforts. The MEM issued new regulations this June, to take effect on August 1, forbidding parking and charging in the public areas of high-rise buildings.

Local governments have also weighed in, Shanghai’s municipal government implementing new safety regulations on non-motorized vehicles on May 1, providing detailed rules on batteries, charging, parking, and vehicle management. The local government also set up over 1,600 parking and charging areas, and installed over 4,600 control systems, which automatically keep elevator doors open and send warnings to compound guards if it identifies an electric bike placed in elevators.

Meanwhile, just seven days after the Chengdu elevator case, two more charging bikes exploded in Beijing and Shenzhen. And less than two months after Shanghai’s non-motorized vehicle regulations came into force, local police handled over 170 illegal charging cases, identified over 240 bikes with dodgy batteries, and found 6,300 spots where bikes blocked emergency exits and passageways. It may take time and effort for electric bike owners to realize safety matters more than (in)convenience.