I have owned my K900 5.0 since Oct 2014 with no problems. It was delivered to my U.S. dealer in March 2014 - I test drove it then with packing material still in place. In Feb 2020 I was going to take a major trip so I had AutoZone replace this original battery.
My new Genesis GV80 picked up upon arrival to U.S in December has already had a battery replaced.
I had a Cadillac 06 STS - it went through a battery every year I owned it (6).
You win some, you lose some.