NHTSA Complaint #11699151 — 2023 NISSAN ARIYA

DEFECTIVE COMPONENT & FAILURE MODE The vehicle suffered a failure in the 12-volt battery system, potentially involving the DC-to-DC Converter or the associated charging logic. This malfunction caused the lead-acid 12V battery to be severely overcharged and boiled while the vehicle was plugged in and parked. CATASTROPHIC SAFETY HAZARD The failure resulted in the release of highly toxic and flammable gases into an enclosed residential space (my garage), posing an immediate, life-threatening risk: TOXIC GAS POISONING: The boiling battery released a massive amount of Hydrogen Sulfide gas, identified by the distinctive, strong rotten-egg odor. H2S is a cellular asphyxiant and is fatal at high concentrations. EXPLOSION/FIRE RISK: The boiling battery also released highly flammable Hydrogen H2 gas, creating an explosion hazard inside the closed structure of the home. CHRONOLOGY OF EVENTS Tues, 11/11/25 (approx. 5:00 PM): Noticed strong rotten-egg smell in the garage while the vehicle was charging. 5:30 PM: Called local gas company due to fear of a gas leak. 6:30 PM: The smell was still strongly detectable, indicating dangerous lingering concentrations. Suspecting the car, immediately unplugged. 7:00 PM: Identified the car as the source and moved the immobilized vehicle outside. 9:05 PM: Contacted Poison Control due to chemical inhalation/exposure risk. (immediate / risk of delayed symptoms). MANUFACTURER CONTACT & CURRENT STATUS Manufacturer Contact: I have notified Nissan Consumer Affairs of the safety hazard and received Case Number: 55990119. Current Status: The vehicle is currently immobilized and will be sent to dealership for repair. The defective components (battery and converter) are intact. Medical Status: I sought medical consultation and am monitoring for delayed neurological or respiratory effects (pulmonary edema) known to occur after H2S exposure.