The car battery was draining without any explanation. Had the battery and alternator checked and both were perfectly fine. After many instances of having to call someone to jump start the car when I knew I hadn't left anything on, I had no answers and I was really frustrated. One night I parked my car, made sure no lights were on or anything was left on, went inside for a few hours, and came out to see that the automatic headlights were on that I started to think they were the cause of the drained battery. It's as though they turned off when I parked and locked the car but turned back on afterward. Once I stopped using the auto headlights, didn't have the problem anymore. I haven't had a battery issue since. Definitely annoying, but I did not get a quote to fix it.

Something draining battery. We've narrowed it down to the lights. First time it happened. I thought perhaps I left something on. So we charged it, drove it and when we returned, made sure everything was off. Next day, while it was not completely dead, it was very weak. Charged it again, drove it. This time I turned the lights to the "off" mode instead of the automatic. Next morning, it was charged, so I took it to a mechanic because I thought it was the battery. They tested the battery, the alternator and some other tests. He said not battery or alternator. But he suspected an electrical wiring issue particularly with the lights. Also found someone else reported this issue on another forum. They also said battery drained when lights were left in "auto" mode. I think Hyundai should provide fix for this issue.