I see the YouTuber did a year two test of his ID3's battery degradation and it's now sitting at 11% by his calculation after an 8% loss in the first year. I realise he wasn't looking after the battery in year one but he says that he was kinder to it in year two.
I think the general consensus is that the degradation should reduce year on year but it still seems high.
Anyone else done similar tests with their car?