Puzzling startup
With the temperature at -17°C (1.4°F), the key fob opened the Kona fine, but, while trying to start the vehicle with my foot on the brake, the only symbol on the cluster was the yellow key icon on the lower left. Repeated the process with the same result. On the third or fourth time, the red battery icon also appeared. Repetition with the same result. Opening the large AV screen showed it asking for confirmation. Using my mobile, not the Hyundai, I phoned my wife and, while explaining the situation to her, the Kona came to life as it normally should.
About two and a half hours earlier at -20°C (-4°F), my wife used the warm-up feature while it charged and left it in Winter Mode. The Kona traveled about 5.2 km (3.25 miles) with heat on as well as one seat heater part of the time, then sat turned off. So, did the 12V battery get low due to the warm-up even though the Kona was charging? Would the cold weather and short trip (our usual) be a major factor? What occurred to cause it to come to life?