Battery Temperature Correlated to Ambient

It has been reported by Nissan that battery longevity is most affected by battery temperature, and battery temperature by climate. I monitor my LEAF battery monthly for capacity and temperature using LeafSpy, and share below the temperature data from about the time the car came to us until the present. We park the car in the shade at home, try to avoid parking on hot asphalt in the summer when out and about, charge during the cool hours, and do not fast charge. Car is used most days for about 15-20 miles.

Ambient average is calculated from historical data using the simple average of (max+min)/2



So at least for our use profile Nissan is correct to within a few degrees.

I have been driving Leafs as daily drivers in Phoenix since June 2011 (except for about one month) and I agree that battery temperature tracks average ambient temperature closely. A DCQC will spike the battery temperature a bit, but the battery pack cools off to somewhere near ambient temperature while parked overnight. I also notice the battery pack temperature drops during highway driving after DCQC due to air flow over the battery housing.