There's phxsmiley who claims that he was losing 1 GID a day on L2 charging, and stopped losing GIDs on L1 charging. He also said his coworker always charged L1 and never lost capacity.SierraQ wrote: An interesting theory but not likely a significant culprit otherwise we'd be seeing capacity issues everywhere. As it is there is strong evidence that this is solely related to heat and not methods of charging, driving, age, etc. Chargers damage batteries by overcharging or injecting current into them too fast. The Leaf does manage this. Whether it is ideally managed, especially in higher temps, who knows. Still, I don't believe there is clear evidence as yet whether L1 is better than L2. If it is the factor would more likely be the charging voltage/amperage/rate and not the manufacturer since these devices are glorified power switches. Some have reported higher GID counts under L1 but it could be coincidence or insignificant. We would need someone in AZ who has always charged at L1 to have a good comparison point. (Do we have someone like that?)
Maybe it's not L1 vs L2, maybe it's two different EVSE that implement the J1772 protocol with some nuance that combined with heat damages the batteries.
The GE WattStation case is a clear example.
I may be naive, but I believe that Nissan did all the extreme testing to the car to be confident enough to start mass prodution. However, these extreme testing have in common EVSEs designed by Nissan, and being a software engineer I have by experience fallen to the pitfalls of interfacing with external devices that implement features slightly different, and trigger bugs in areas where some things were not supposed to happen.