Nissan’s Open Letter To The LEAF Community, Starts Independent Advisory Board On Battery Capacity Loss

SEP 24 2012 BY STAFF 15

At this point most readers are aware that many Nissan LEAFs in very hot southern climates, like that of Phoenix, Arizona, have experienced some battery capacity loss, which has been translate by Nissan’s on board instrumention as “bars lost.”  The debate has been how much loss has there been, is Nissan’s instrumentation over exaggerating that loss, and what is an acceptable amount to lose?

Understandably, Nissan has been more than a little guarded on the subject, and several theories have been floated (instrument failure, heat, mileage, driving style of those with loss) by the company ahead of results from actual testing of consumers cars done by Nissan at their testing facility in Casa Grande, Arizona.

Just recently Mark Perry, Nissan’s Director of Product Planning and Advanced Tech, said that LEAFs, on the average, are still on a “glide path” to 76% capacity after 5 years/60,000 miles, very close to the expected national average of 80% (story here).

Nissan has also decided to convene an independent global advisory board, which is to headed up by Chelsea Sexton, noted EV advocate.  This board will also examine the issues and recommend a course of action for the company to follow, as well as aid Nissan in communicating better with their customers.

Nissan Exec Carla Bailo has issued an official letter to the LEAF community via Facebook and announcing the test results and the formation of this advisory committee:


Carla Bailo, Senior Vice President, Research & Development – Nissan Americas

Happy eve of National Plug In Day. We’re excited that Nissan LEAF owners are gathering nationally tomorrow to celebrate zero-emission motoring, and appreciate that so many of you are sharing your enthusiasm with others. You are truly our best ambassadors to the next generation of passionate EV drivers.

We also want to update you, the LEAF community, on our findings regarding battery capacity loss concerns expressed by a number of owners in the Phoenix market. Nissan takes customer concerns seriously, and we know many of you have been interested to hear what we’ve learned in our thorough investigation, and what it all means.

We identified seven LEAF owners in the Phoenix area who had reported concerns with their vehicles.  With their agreement we brought the cars to Nissan’s Arizona test facility, where we removed the batteries for evaluation, measured capacity, and conducted voltage testing on individual battery cells. These tests were diagnostic only; no modifications were performed to the battery packs themselves.

After returning cars to their owners, we analyzed the results of our tests, with specific emphasis on the rate of actual capacity loss for each vehicle. Our goals were simple: to determine 1) if there were any defects in materials or workmanship in the individual batteries or vehicle systems; 2) if the batteries were performing to specification; and  3)their performance relative to the global LEAF population.

This week, we will meet with these LEAF owners to share our findings on their individual vehicles. In the mean time, we can report the following overall findings:

  • The Nissan LEAFs inspected in Arizona are operating to specification and their battery capacity loss over time is consistent with their usage and operating environment.  No battery defects were found.
  • A small number of Nissan LEAF owners in Arizona are experiencing a greater than average battery capacity loss due to their unique usage cycle, which includes operating mileages that are higher than average in a high-temperature environment over a short period of time.

While we understand that some LEAF owners are concerned about battery capacity loss, we want all owners to remember that all battery-electric vehicles – and all lithium-ion batteries – demonstrate capacity loss over time. So while your LEAF may have been able to travel a certain distance or more on a charge when new, its range will decrease as the battery ages, miles accumulate and gradual capacity loss occurs. This loss in capacity will occur most rapidly in the early part of your battery’s life, but the rate should decrease over time. Information on gradual battery capacity loss is available in the paperwork that was delivered with your vehicle, in the owner’s manual and on the many vehicle resources available at

It is also important to put the scope of these concerns in perspective. Globally, there are more than 38,000 Nissan LEAFs on the road that have travelled more than 100 million zero-emission miles, and we expect these vehicles, in normal operating conditions, to retain 80 percent of battery capacity after five years. As each user’s operating characteristics are unique and many factors impact battery capacity, we can expect some vehicles to have greater than 80 percent capacity at five years, and some vehicles to have less.  In Arizona, we have approximately 450 LEAFs on the road.  Based on actual vehicle data, we project the average vehicle in that market to have battery capacity of 76 percent after five years – or a few percentage points lower than the global estimate.   Some vehicles in Arizona will be above this average, and some below.  Factors that may account for this differential include extreme heat, high speed, high annual mileage and charging method and frequency of the Nissan LEAFs in the Phoenix market.

We at Nissan stand by our product, and we also stand by our customers. Recently, we’ve asked Chelsea Sexton, a passionate advanced technology advocate, to convene an independent global advisory board. Members would be selected by Chelsea, not Nissan, and they would recommend their own mandate, but our hope is that they would hold up a mirror to us and help us to be more open and approachable in our communication and to advise us on our strategy. We should have more information on the advisory board in a few weeks.

As we work with individual owners to ensure their satisfaction, we are appreciative of your continued support of both the Nissan LEAF and the electric vehicle movement, overall. We look forward to continuing our dialogue here in the MyNissanLEAF forum and within the Nissan LEAF community.

Best Regards,
Carla Bailo
Senior Vice President, Research & Development – Nissan Americas

Categories: Nissan


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15 Comments on "Nissan’s Open Letter To The LEAF Community, Starts Independent Advisory Board On Battery Capacity Loss"

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Much of the initial response at MNL has been negative to this, but I think this is actually a positive first step by Nissan. They are not just sounding the “all is normal” call, but seem to be acknowledging that a minimum they need to do a better job of communicating heat/capacity loss issues.

More corporate “spin.” IMHO. Nissan did not actually drive those “cars tested” to check how the batteries performed. One can do a “test” but using a TOTALLY INADEQUATE (shouting intended) test protocol come up with almost any result desired. Day to Day driving and how the cars can be used is THE test, and the owners gathered a range of the “problem” cars and others virtually brand new and did a very thorough functional test last week. THOSE results are clear….several of the early Phoenix cars are losing almost 35-40% of their original battery range. THAT is simply NOT acceptable in an 18 month period. Our Leaf (VIN #320) has nothing like that kind of battery loss over our 18+ months of use here in SacraHOTo, but then we do not get as many 110+ degree days and we COOL DOWN at night here. Nissan’s battery pack design simply was and IS not durable in exceedingly hot environments, while there is no such complaint about the Volt (we also have VIN #679 Volt) in that area it seems (the Volt has a more sophisticated battery cooling/temperature control system).

Does your LEAF show any battery capacity loss after driving in Sacramento for 18 months or do you still at 12 bars?

Based on extremely low percentage of compliants, unless you live in a desert you need not worry about abnormal battery loss due to ambient temperature. There are more owners with 20K to 30K miles with absolutely no loss (just not in Arizona obviously)!

Spike, Houston is not a desert, but is definitely is not a climate the LEAF battery can handle. 15 months, 25k miles, and I am down to roughly 80% capacity with 10 / 12 capacity bars showing (even though that is not the best method to measure). The main issue is I was not expecting this when I leased my car. I will not be able to make my 66 mile round trip commute to work this time next year. I have gone from doing 75 mph to and from work on the tollway to taking the “free” highway just to take advantage of traffic (not really and advantage) and drafting to make the commute. The battery clearly has some problems when it comes to high cycles in hot weather. By comparison, high cycles in cooler weather do not seem to be an issue. I also have not read anything on Tesla Roadsters having this rapid capacity loss in hot environments, although I have no data to show that there is anyone driving a Roadster 20k miles / year in a hot climate (that would probably not be much fun). 21 months to go on this lease…Tesla, could you get… Read more »

No battery loss at all here in SacraHOTo. Still at 12 bars, and full charge displays of 103-108 miles on the Guessometer Display.

“We at Nissan stand by our product, and we also stand by our customers.”

Then warrant the damn batteries for retained capacity after a certain time/mileage and for the “small number” of batteries that fail prematurely, honor the warranty and replace them.

This is not a rocket science. This is a corporation at its worst.

Sweet try, but sugarcoating your denial of responsibility is not good enough, Nissan.

I greatly respect Chelsea Sexton, but am uncertain about how independent a leading EV advocate would be as head of an investigative panel. It’s going to have to be a wait and see thing – will Chelsea hold and confirm her deserved respect by not ending up as a celebrity figurehead Nissan uses to mollify the community in which she is held in high esteem, but being instead truly independent and insistent upon the truth, even if the truth hurts.

The problem is that Nissan undertook a science experiment. Nobody in the industry thought the design was right. They have zero thermal management. Lithium batteries don’t like heat. The standard test to estimate (extrapolate) life is a high-temperature test. Whereas GM built a huge battery test lab to put their new and untested batteries through many driving scenarios in the lab, Nissan did the experiments in-situ. All you Leaf owners are guinea pigs. Nissan will get a ton of data from every vehicle they can pour through to come up with the right thermal management requirements for future BEVs. That is, if they do not poison the well with their first gen Leaf!

They just set themselves up for bigger trouble later… when these Leaves have 60% in hot areas after 4 years, they’ll have a nightmare on their hands… also having no capacity warranty but creating an illusion that there is will bite them later. They should have never mentioned 76% or anything.


What is it about high-mileage LEAFs in Arizona? There must be high-mileage LEAFs in other states. Do they also have reduced battery capacity and/or instrumentation problems?

There are “high-mileage LEAFs in other states” and NO there are no complaints from drivers anywhere other than in the “furnace of America” or so it seems.

Sorry Carla & Nissan. No pass. I need you to stand behind me as an owner, and that has not been happening for months on end. My first summer in Phoenix has been hell because I have watched my car degrigate weekly with no love from Nissan.

I have 5 stars on all my reports. My dealer and I have NEVER heard about this mileage limit or freeway limitation. My car is already missing 30% charging time and is accepting 30% less kw than when new. All this after less than 1 year of ownership!

You just dont withold car performance information like this from reporters and potential buyers; then dodge the issue with an advisory board. I am so done with this car in Phoenix, and this evil corporate behavior.

Come pick up my car Nissan. Then you can adjust the cars limitations.

But you DO NOT have me buy a car THEN change key buying information.

@adorandax. There are leafs in other states with 40k miles, no lost bars or gauge issues.

There are also leafs with only 8k miles and a bar missing here in Phoenix.

In contrast to this stone-walling by Nissan on the battery issue in Phoenix, Nissan has been TERRIBLE with ignoring complaints about the outdated GPS maps in the 2011 Leaf models. Our area of Sacramento had been populated for FIVE years and none of the streets are present on the GPS maps in our 2011 Leaf, but fully details in our 2011 Volt. When GM had concerns voiced about “fire dangers” in the Volt after the NHTSA crash tested Volt caught fire two weeks or so after the crash-testing, GM even offered to BUY BACK any Volt that was a worry to a customer. GM then redesigned the battery protection shell and retrofitted ALL the early delivery Volt vehicles! Where is the integrity of Nissan ? Clearly Nissan USA lacks the corporate concern for its products that GM has shown so clearly and honestly with the Volt.

And I have NEVER been a “GM fan.” We have not owned ANY American car since 1969, and have regularly owned Toyota, Honda,Mazda, Infiniti, Lexus, Acura, BMW, Audi, and VW. I have NOT at all been pleased with any of Nissan’s support for the Leaf and it’s owners.

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