NHTSA Complaint #11707768 — 2024 KIA EV9

I would also like to highlight the serious safety concern due to cell deviation (imbalance) along with SOC (State of Charge) mismatch as per my car's BMS (Battery management system) which is present in my vehicle and shared with Kia corporate. In an electric vehicle, the high-voltage battery cells, the Battery Management System, and the battery coolant system function as a single integrated safety-critical system. When battery cells are imbalanced and there is a significant mismatch between the state of charge displayed to the driver and the lower usable energy calculated by the Battery Management System, the weakest cell can reach its safe operating limit under normal driving load even though the dashboard indicates sufficient charge. If this condition is combined with a battery coolant system fault, such as low coolant level or air in the cooling circuit, battery temperatures can rise unevenly and further reduce safe operating margins. To protect the battery and prevent thermal or electrical damage, the system must immediately limit propulsion or enter a reduced-power (“turtle”) mode without driver input. Because these protective actions can occur suddenly and without advance warning, they can restrict acceleration or vehicle speed during ordinary driving conditions such as merging or maintaining highway speed, creating an unexpected loss-of-propulsion safety risk rather than a mere inconvenience. This is equivalent to a faulty fuel gauge for a gasoline car but with more immediate and severe consequences Sudden Power Cutoffs: If a single battery cell's voltage drops below a safe threshold, the Battery Management System (BMS) will shut down the entire pack to prevent permanent damage. This can happen even if the dashboard shows 25% or more remaining, potentially leaving you without power while driving. Loss of Vehicle Control: A sudden shutdown can lead to a loss of power steering and braking assistance, which is hazardous in high-speed or heavytraffic situatio