I’m frankly not sure my dealer even knows it has a battery. Been in from time to time for warranty stuff I’ve detailed here already and they don’t do much. Annual battery certification? They’ve never heard of it.
We are 32 months and 24,000 miles into the lease and at full charge it still reports the same on the GOM about 83 or so miles. Extended charge is 94 or so.
In theory it should have measurable degradation by now, less than 10% certainly but a few miles of loss wouldn’t be out of line with what Tesla and other EV’s experience in their limited existance.
The B class battery is heated and cooled as needed, full charge isn’t really full (even extended range charge) and 0% isn’t really empty so the pack stays within it optimal band.
Any added degradation from the stress of DC fast charging doesn’t exist here either because the car never offered it.
So our degradation should be about as low as it can be. Whatever that is.
Nissan Leaf batteries don’t have active (liquid) cooling, so hot climates and DC charging can be rough on it. Vast majority of Tesla’s not only have super charging enabled, but using it is free on some level encouraging people to utilize it. There has to be some amount of added degradation for repeated fast charging but only Tesla and Nissan have that data collected from cars and they aren’t likely to share it.