China Warns of E-Bike Charging Risks Amid Extreme Heat

Chinese authorities have issued a safety warning about electric bicycle charging during high-temperature weather, highlighting the increased fire and explosion risks when batteries are charged in extreme heat. The advisory from Xinhua News comes as much of China experiences one of its most intense heatwaves on record.

The Hidden Danger of Midday Sun

According to the Xinhua advisory, many e-bike owners are unaware that after exposure to midday sun, e-bike bodies and batteries can reach temperatures above 60°C (140°F). At this temperature, battery cells become extremely unstable, and immediately charging a hot battery can trigger thermal runaway—an irreversible chemical reaction that can cause short circuits, spontaneous combustion, and even explosions.

“During high-temperature weather, e-bike safety hazards increase significantly and are one of the fire-triggering factors,” the advisory warned.

The warning also addresses a second compounding risk: humidity. Recent short-duration heavy rainfall and overcast weather across much of China have significantly increased air moisture levels, and charging e-bikes in humid or rainy environments poses additional safety hazards that cannot be ignored.

The advisory urges owners to charge scientifically and reasonably, inspect equipment promptly, and avoid risks.

A Record-Breaking Heatwave

The safety warning arrives amid one of China’s most severe summer heatwaves in recent memory. July 2026 was the second-hottest July on record, with average temperatures 1.3°C above the historical average. Xinjiang, Sichuan, and Chongqing all set record-high monthly average temperatures, and the national meteorological station at Aydingkol Lake in Xinjiang recorded a maximum temperature of 50.2°C.

Chongqing, one of China’s famed “furnace cities,” endured 26 consecutive days of high heat in July, with temperatures exceeding 40°C for a full week and peaking at 41.6°C, as Xinhua English reported.

The heat is expected to persist. According to China Economic Net, August is forecast to see four significant heatwave periods—August 7-9, 11-14, 22-25, and 29-31—with the National Climate Center warning of a high probability of regional extreme heat events in central China, southwestern China, and Xinjiang.

A Nation of 400 Million E-Bikes

The stakes of this warning are substantial. China has approximately 400 million e-bikes in circulation, making it the world’s largest e-bike market. According to Southern Metropolis Daily, Guangzhou alone has over 6 million e-bikes, with more than 3 million classified as old (5+ years) or non-compliant vehicles with higher fire risk.

The fire statistics underscore the seriousness of the threat. According to China Fire and Rescue data cited by Southern Metropolis Daily, approximately 80% of e-bike fires occur during charging. In 2023, China recorded 21,000 e-bike fire incidents, a 17.4% increase from the previous year. Fire incidents have been rising annually, from 3,000+ in 2018 to 18,000 in 2022 and 21,000 in 2023.

Thermal runaway is the primary mechanism behind these fires. As GeekNEV explains, in summer, battery casing temperatures can reach 60°C, with internal core temperatures exceeding 80°C, making the casing prone to softening and deformation and increasing thermal runaway risk during prolonged charging.

Government Response and Progress

The advisory is part of a broader government effort to improve e-bike safety. In April 2024, the State Council Safety Committee launched a nationwide “full-chain rectification” campaign targeting safety hazards across production, sales, use, parking, charging, and management. New mandatory national safety standards for e-bikes took effect on September 1, 2025, covering fire-retardant performance, battery safety lifespan, anti-tampering technology, and identification codes.

These efforts have shown measurable results. According to the State Council Information Office, China recorded 7,048 e-bike-related fire incidents in the first half of 2025, a 44.7% decrease compared to the same period in 2024. The Emergency Management Department reported that e-bike fires dropped from 5.6 per million vehicles per month at the start of the rectification campaign to 2 per million, with casualties down 86%, as Jiemian News reported.

The government has also been offering trade-in subsidies to encourage consumers to replace outdated e-bikes, with nearly 9.06 million new e-bikes sold through the program in 2025.

What to Watch For

As the August heatwave continues, authorities are likely to intensify public safety education campaigns around e-bike charging. The combination of extreme temperatures, high humidity, and a massive e-bike fleet creates a volatile environment where even small lapses in charging safety can have serious consequences.

For the estimated 400 million e-bike owners across China, the message from this advisory is clear: allow batteries to cool before charging, avoid charging in humid conditions, inspect equipment regularly, and never underestimate the dangers of extreme heat. With four more heatwave periods forecast for August, vigilance will be essential in preventing avoidable fires and protecting lives.