A Study on the Fire Occurrence Characteristics of Personal Lithium Battery Devices

According to fire data from the National Fire Data System (NFDS) Big Data Platform, fires involving personal lithium-ion battery devices surged 3.2-fold, from 69 cases in 2019 to 219 in 2025. As lithium batteries are increasingly being adopted in personal devices such as electric kickboards, electric bicycles, and portable chargers, the associated fire risk has increased. However, a comprehensive analysis of fire occurrence characteristics and ignition causes for these devices remains limited. To address this gap, this study analyzed 1,157 personal lithium battery device fires from 2019 to 2025 and examined the occurrence characteristics by device type, location of origin, time of day, ignition cause composition, and casualty characteristics. The results revealed distinct variations in the ignition-cause composition across different device types, indicating that device-specific approaches, rather than uniform prevention measures, are necessary. These findings provide foundational data to establish targeted fire prevention measures and improve safety standards for personal lithium battery devices.