Alternatively, it could be used a state of charge tracking mechanism that conceals battery degradation. Say the battery has 100KWh, but the remaining energy gauge reads zero after 80KWh are expended. You could be degraded to 90KWh but you wouldn't perceive any reduced usable energy until it degrades below 80KWh.

This seems contrived - the whole point of incomplete charge / discharge cycle is to spare the battery from degradation.

Yes, and my point is that the mechanisms to prevent battery degradation can often end up masking the degradation. This isn't nefarious, it's the byproduct of good state if charge management.

+1-anecdata: 2013 Leaf 100K Km aka 100megameters, down one of the 12 bars on battery life. I do follow the 'charge to 80% rule' quite rigoursly

I have a 2015 Leaf with 45k miles on it. Battery state of health is 90% according to Leafspy. I’m in the SF Bay Area. Maybe it’s because of the more temperate climate here, but we’ve just had zero battery degradation problems.

My gut feeling is temperature and constant deep discharging probably explain most of the issues with Leafs. Like a lot of things there is a curve with a knee and it's easy to drive a leaf so you're on the wrong side of it.

I don't really know how Leafs batteries are connected but one could also expect that a smaller battery pack has less redundancy. If due to bad luck a couple of cells go bad you lose a lot of capacity. More likely to happen the less redundancy you have.

> […] after 60k km.

So 60 mega-metres? 60 Mm? :)

Edit: Downvotes? Really? Lighten-up people. Sheesh. (And it is technically correct. :)

Right? The rules don't say "no fun allowed."