Apparently the Idaho National Laboratory (INL) has been conducting an experiment with two pairs of Nissan Leafs to compare battery degradation with charging off L2 versus charging with Quick Charging: QUICK CHARGE = QUICK DEGRADATION? | Simanaitis Says There is a marked effect on using quick charging on Nissan Leafs. Further, the batteries themselves have degraded significantly at 40k miles (over 20%). These cars are tested under a pretty significant duty load - about 140 miles a day with two near full charge cycles. What's even more disturbing is the slope of the degradation. The Panasonic paper on NCA degradation showed a slope that was steep and first and then leveled out. The INL study on the Leaf has an accelerating degradation. Paper by Panasonic on restricting DoD for longer cycle life, look at the 2nd graph: Development of High Power and Long Life Lithium Secondary Batteries Still though, it points to the fact that Nissan's choice of using an air cooled battery pack with lithium manganese chemistry was pretty short sighted.