I'm also curious if there is a way for us to check this ourselves. I would think a dealer would be able to check that with the diagnostics port. I was thinking about this very thing just last week after watching a youtube video on a 5 year old Hyundai Ionic with 60,000 miles on it. The guy claims he charged it to 100% each night and drove it hard. He then connects an OBD2 connector and shows the battery's health. 100% health! Zero Degradation. I just bought a used 2020 HD ELW in December and I would love to be able to check the SOH of mine. I wonder if there is some 3rd party software and a cable available for HD's. I know this sort of thing exists for some other vehicles like Ford's for example.