Hey guys, this is my first Volvo I've ever owned and I've recently had a random issue where I parked in the garage, pulled the key out and set it in the center console and left the car unlocked in my garage overnight. When I went to leave for work in the morning it had no power at all! Not even interior lighting...no sounds, nothing. I was 100% positive I didn't leave any lights on or anything. So I got my buddy to give me a jump. Started right up as if nothing had happened...battery had almost nothing left in it (judging by touching the 2 jumper cables together). This has not happened again but it has only been 1day. I've recently also had an issue where the cabin fan was blowing air inside while the key wasn't even in it...this was over an hour after it was parked about a week ago. Now I had a dead battery. What could be my issue???