A mechanic inspects an Ioniq 5, Hyundai Motor Company's battery-electric vehicle. (Hyundai Motor Group)

Hyundai Motor and Kia on Thursday said there had been no fire incidents due to overcharging their electric vehicles as the automakers emphasized the safety of their battery management system, or BMS, in the wake of consecutive EV fires spreading fears across Korea.

The companies dismissed the claims that point fingers at overcharging behind the reason for EV fires, explaining that the BMS closely monitors an EV’s charging status in real-time and works in conjunction with the charging controller to completely prevent overcharging to bring the likelihood of overcharging issues to near zero.

According to the carmakers, the BMS, which works like the brain of an EV, checks various battery-related parameters including voltage deviation, insulation resistance, current and voltage changes, temperature, overvoltage and undervoltage.

“The biggest feature of our anti-overcharging technology is that it has a multi-layered safety system, meaning that if an error occurs in the detection stage, there are three different stages of overcharging prevention technologies,” the automakers stated.

In the first stage, the BMS and charging controller manage the optimal charging current to ensure safe charging within the high-voltage battery’s charging range. The BMS constantly monitors the battery's charging status and immediately shuts down charging if it deviates from the normal range.

The third stage becomes activated when the controllers of both the vehicle and battery fail, forcing a physical safety circuit to close the switch of the current path.

An illustration of Hyundai Motor Group's battery management system (Hyundai Motor Group)

Once the BMS detects signs of a battery malfunction, it not only conducts safety measures but also notifies drivers depending on the level of severity and advises them to visit a nearby center or call the automakers’ emergency support center if driving the EV is not an option at the moment.

The automakers said they plan to push for developing a system that can automatically notify public authorities including firefighters and police officers if the BMS deems that there has been a severe battery incident such as fire.

Hyundai and Kia pointed out that their EVs are also equipped with an "exceptional" battery fire delay system, noting the shorter time period it took for the authorities to put out a Kia EV6 fire in comparison to a Mercedes EQE fire earlier this month.

The Mercedes EQE incident, which took place in an underground parking lot in Incheon on Aug. 1, took eight hours and 20 minutes to put an end to the blaze while the Kia EV 6 case, which happened in a parking tower in Geumsan County, South Chungcheong Province, on Aug. 6, took one hour and 37 minutes to put out the fire.

“All safety technologies developed based on the expertise and know-how accumulated by our research and development teams are applied to Hyundai Motor Group’s EVs,” said an official at the auto conglomerate.

“We will continue to strive for the development of new safety technologies instead of being satisfied with the level of technology we have now to ensure that our global customers can drive our EVs without fear.”