An analysis of the recent electric vehicle (EV) fire in an underground parking lot in Cheongna, Incheon, has identified the battery pack beneath the vehicle as the likely source. Investigators suggest that external damage to the battery cells, possibly from an impact, may have triggered the blaze. The fire destroyed 78 vehicles, damaged 880 others, and caused significant disruptions, including widespread power and water outages for residents.
On Sept 26., the Incheon Metropolitan Police Agency’s forensic team, citing a report from the National Forensic Service (NFS), stated that “the fire likely originated from the battery pack beneath the vehicle.” The NFS further indicated that “an external impact to the vehicle’s underside may have damaged the battery cells, leading to insulation failure and subsequent ignition.”
The fire completely destroyed the Battery Management System (BMS), preventing data retrieval. The police, along with the NFS, Incheon Seobu Fire Station, and Korea Automobile Testing & Research Institute, conducted three joint inspections, including the disassembly of the EV’s battery pack, to pinpoint the fire’s origin by closely examining the battery modules and cells.
In EVs, batteries are structured in stages: cells form modules, which are then combined into a pack. The battery cells in the Mercedes-Benz EQE350 involved in the fire were supplied by Chinese manufacturer Farasis Energy. A police official stated, “Based on the NFS findings, the investigation into the cause of the EV fire will continue.”
This analysis may shift the narrative surrounding the Mercedes-Benz fire. Initial speculation suggested a defect in the Chinese-made battery, but if an impact during driving contributed to the fire, Mercedes-Benz could face reduced liability. Police are also investigating the vehicle owner’s driving route prior to the fire.
Some experts believe the monitoring function of the Battery Management System (BMS) warrants further scrutiny. The BMS is designed to alert the owner to any battery irregularities, and it’s crucial to determine if any warnings were issued before the fire or at the time of impact.
Typically, when the vehicle is turned off, the BMS enters a power-saving mode, becoming inactive after a set period. However, under certain conditions, such as temperature fluctuations, the BMS can reactivate while the vehicle is parked, sending alerts to the owner via a smartphone app, text message, or email, depending on their settings.
A Mercedes-Benz Korea representative commented, “We are fully cooperating with the authorities’ investigation,” but added, “It is difficult to disclose details related to the ongoing inquiry.”
