LG Chem says that Ionic and electric buses use the same battery cells, concentrated fire only in Kona, “it is not caused by defective battery cells”.
Hyundai Motor has decided to take corrective actions (recalls) voluntarily for the electric car ‘Kona’ that is catching fire one after another, but the controversy over the cause of the fire is rather growing.
According to the electric vehicle and battery industry, Hyundai has refrained from making official comments regarding the cause of the fire in Kona, while the Korean Ministry of Land, Infrastructure and Transport and LG Chem, a battery supplier, are in a confrontation with each other.
The ministry notified Hyundai Motor’s decision to recall the day before, and said, “It was confirmed that a fire could occur due to an internal short circuit, due to defective battery cell manufacturing of high voltage batteries.”
At the same time, regarding the contents of ‘manufacturing defects’, they added that “the separator between the positive and negative plates was damaged due to poor quality during the manufacturing process.”
Although the ministry used an ambiguous expression that ‘the possibility was confirmed’, the cause of the fire was pointed out as a poor battery cell quality.
For this reason, Kona battery supplier LG Chem refuted the announcement from the ministry through a statement.
LG Chem said, “It was announced in the statement that the exact cause of the fire has not been identified,” and argued, “It cannot be said that the cause of the battery cell defect due to damage to the separator was leading to a fire.”
LG Chem then emphasized that “we will actively participate with Hyundai Motor Company in the investigation to determine the cause in the future.”
Same battery cells used in Ioniq and electric buses
The battery cells supplied by LG Chem to Kona are used equally in Hyundai’s electric buses and Ioniq electric vehicle models, but fires are intensively occurring only in Kona. Since the launch of the Kona EV in 2018, there have been a total of 13 fire accidents known to date globally. Recently, on the 4th, a fire broke out in Kona, which was parked in the underground parking lot of an apartment in Dalseong-gun, Daegu in South Korea, and the vehicle was burned down.
LC Chem suggests fault in Kona specific battery pack
Even taking this into account, LG Chem is more concerned with the possibility of defects in the manufacturing process of ‘battery pack’ and ‘assembly’, which are manufactured for each vehicle model using battery cells, rather than damage to the separator due to poor quality in the manufacturing process of battery cells.
In the case of Kona, it uses a battery pack made of 57-60 battery cells. The assembly is a high-voltage battery system with five such battery packs plus a battery management system (BMS) and a cooling system. Battery cells are produced by LG Chem, but packs and assemblies are produced by HL Green Power, a joint venture owned by Hyundai Mobis and 49% by Hyundai Mobis.
25,564 Kona Electric recalled
Hyundai Motor Company plans to carry out the recall of 25,564 Kona units manufactured from September 29, 2017 to March 13, 2020. According to the recall, Hyundai Motor Company will replace the battery after updating and checking the software.
As a result of checking the recalled vehicle after updating the BMS, Hyundai Motor Company plans to replace the battery immediately if any signs of battery abnormality such as excessive cell-to-cell voltage deviation or rapid temperature change are found.
Even if no abnormality is found, if an additional abnormal change is detected during the regular monitoring of the updated BMS, it plans to limit charging stop and start-up.
The Ministry of Land, Infrastructure and Transport and the Korea Automobile Safety Research Institute (KATRI) plan to verify the adequacy of the cause of the defect and the recall plan suggested by the manufacturer through a defect investigation currently underway such as a fire reproduction test.