NHTSA Complaint #11571634 — 2019 KIA NIRO PHEV

12 volt battery will suddenly and without warning loose capacity to power the vehicle operating controls and displays including remote key access, start sequence using push button start, and traction battery charging through charging port. While parked and connected to a charging station vehicle ‘died’ in place. This occurred within 10 minutes of last use of remote key to unlock doors, open doors, place shopping bags, close doors, and use driver door push button feature to relock doors. Outside air temperature was mid 20’s Fahrenheit. Traction battery was fully depleted per dashboard miles available display as vehicle driven 20 plus miles using hybrid vehicle mode just prior to parking at charging station. Vehicle was removed from charging station connection and 1.5 hours later jump started using connection under hood. After start was driven just under 4 miles to home garage where plugged into 110 volt home charger. Multimeter on 12 volt system after recharge of traction battery read over 12 volts. Appears that control system for maintaining charge on 12 volt system using traction battery has a flaw that fails to detect 12 volt battery condition and react correctly. While this occurred this time while vehicle stopped and shutoff there is potential for such to occur while vehicle in a roadway at highway speeds causing vehicle to loose all power as 12 volt system powers all operating logic. As a practicing engineer over 50 years and college instructor of engineering for about 40 years it appears that there is a software error in assuring 12 volt system intact and a failure of the software to identify potential problem, notify operator, provide a manual reboot of operating system before 12 volt system reaches failure level if it ever did. Unlike alternator equipped vehicles that show failure of alternator no such given on hybrid.