Number of batttery charges in lfe of battery

I have a 2011 LEAF [bought 4/11] and have monitored its battery temp and capacity since 2013 when I got an OBD2 dongle. Here are my observations on the traction battery. I think the number of quick charges [about 90 so far starting at close to 50 kW max] and the battery temp has resulted in the degradation observed – lost about 20% capacity so far. There is no active management system so cooling the battery relies on the temp difference with ambient. My measurements indicate the battery cools very slowly, about 1 deg/hour or less depending on the ambient and battery temperature. On a few occasions, I have measured battery temp in excess of 90F maximum. I stopped doing quick charges in mid 2016 and battery degradation seems to be less but expect capacity to still gradually fade. Anecdotally my analysis of battery degradation reported by LEAF owners in the northwest [mainly WA] and southwest USA [mainly AZ and TX] shows a noticeable correlation between the rate of degradation and location. Degradation is faster in the southwest compared to the northwest, and SF Bay rea is somewhere in between.

Because the Volt battery has active thermal management and no quick charge capability, I don’t expect degradation to be a problem. I don’t know for a fact, but I suspect the battery chemistry of the LG cells is a big improvement over that of the original Nissan battery chemistry. In fact, Nissan altered and improved their battery chemistry in 2013, probably due to the rapid degradation initially observed. Bottom line – I am not too concerned about the degradation of the Volt battery.