Nissan’s first open discussion with EV advocate Chelsea Sexton
Nissan Executive Vice President Andy Palmer answered some questions from electric vehicle (EV) advocate Chelsea Sexton regarding the current and future state of the Nissan LEAF in the US. Ms. Sexton has been asked by Nissan to organize an independent global EV advisory board to provide Nissan with another point of view – that of the consumer. We offer our observations on this 16 minute You Tube video (found here) over the next few days. We are breaking up our analysis so that each post is not overly long.
Ms. Sexton opens the video with a question about the battery degradation issue in Phoenix as that is the hot topic du jour. Specifically, Ms. Sexton asks Mr. Palmer to clarify the annual mileage that was used to establish degradation expectations. The simple answer provided is 12,500 miles per year using the LA4 test cycle. The problem that we have with that is that the LA4 test cycle does not represent reality for the vast majority of drivers in the United States. A graphic representation of that test cycle can be found here, in our article regarding real world range of the Nissan LEAF. The average speed using this test cycle is under 20 miles per hour with a top speed of just over 55 miles per hour reached for just a few seconds. We can exceed both of those parameters just going to the grocery store. What Nissan needs to do is to move away from the LA4 test cycle as a basis for any of their calculations and move somewhere into the realm of the real world. A good place to start would be the EPA’s test protocol that provides the LEAF with a 73 mile range, rather than Nissan’s touted 100 mile range based on the LA4 test cycle. This EPA range is much more aligned with the real world usage that one may expect to see during the normal course of a day. Based on Nissan’s testing, the LEAF battery pack is expected to retain 80 percent capacity in five years, and 70 percent capacity in ten years. Mr. Palmer stresses the non-linearity of this expected degradation (20 percent over the first five years and ten percent over the second five years). As noted below, Mr. Palmer states that speed is a variable in determining potential battery degradation. If the average speed of a given vehicle is higher than the LA4 test cycle average speed, one would reasonably expect greater battery degradation as well as a shorter range per charge. We have long stated that the LEAF is not for everyone. Then again, neither is a Ferrari. One can only be sure of choosing the right tool for the job if all of that tools operating parameters are known up front.
Mr. Palmer goes on to say that Nissan has collected data on 400 of the 450 Nissan LEAFs sold in Arizona via the CARWINGS communication system between one’s LEAF and the Nissan mother ship. Based on Nissan’s analysis of this data, the average Arizona driver is accumulating only 7,500 miles per year on their vehicle. Based on this mileage, these LEAFs are on a path to retain 76 percent of battery capacity at the end of five years (slightly less than the 80 percent expected). Our fifth grade math might be a little rusty, but that comes out to 37,000 miles after five years, versus Nissan’s own projection of 62,500 miles using the LA4 test cycle. Nissan must address this disparity. It is imperative that Nissan develop a clear communication protocol to outline to potential LEAF owners that battery degradation is not the same for all LEAF owners. Mr. Palmer sites four variables:
- Speed and gradient of driving
- Frequency of quick charging
- Accumulated mileage
Nissan must make clear, prior to vehicle acquisition whether by lease or purchase, that these four variables will impact battery life. To not do so will only lead to further confusion and anxiousness regarding the adoption of electric vehicles, especially Nissan electric vehicles. As battery chemistries and vehicle designs change in the future, these variables can be modified or addressed as needed.
We will look at other questions posed in future posts.
Can you better specify the meaning of “Speed and gradient of driving”?
Hi Paolo. My understanding of this would first be driving speed. The faster the speed, the greater the impact on the battery. Secondly, gradient I understand to be the slope, primarily up in this case, that the vehicle is traveling over. Therefore, speed and slope will have an impact over time as both will require greater battery output.