Yes, but you can't extrapolate anything useful from that because of MG's sleight of hand. They adjust the State of Health (SoH) to be something over 100% when new; call it 102% for argument's sake. But any SoH over 100% they report as 100%. So in the first 10 months or so, when the degradation is at its worst, say 102% down to 100%, it appears to the customer that it's not degraded at all. Wow, these CATL / SAIC batteries are great! But eventually the SoH drops to 99.9% and so on.
So after the first year, you might get a reading of 99.5% SoH. This works into the estimated range and reduces the figure from 218 to 217 miles. But it's really a 2.5% degradation (with my assumed initial SoH of 102%, which might be way off). That's the worst year out of the way; the second year might only be say 1.5%, but then the SoH will be down to 98%, so the estimated range would then be 98% of 218, or around 214. It looks like the degradation has increased 3 fold! But it's an artifact of the way they present the SoH. They postpone the panic from the first year to the second year, and by then it's too late to do much about it.
By the third or fourth year, the deception has largely faded away, and the figures tend towards what they really should be.
It may even be that this isn't a deliberate marketing ploy. Not all battery cells are identical. If they aim for say a 100 Ah cell, some might end up as 99.8 Ah and others at 100.3 Ah. To be safe, they call it a 98 Ah cell, and nobody gets less then what they "paid for". That could be the origin of most batteries coming in at around 102% SoH when new. It also means that nobody gets a car that happens to start at say 99.8% SoH; it just sounds like you've been ripped off.
