By on September 19, 2012

Earlier this year, Nissan Leaf owners in Arizona started to observe bars missing from the charge state display of their cars. Instead of the 12 bars that signal a full battery, some saw only 10 or less. This spread like the Arizona wildfires through the EV community. As of today, the discussion at the Mynissanleaf forum  has swelled to 373 pages. Nissan looked at the affected cars, and so far has not rendered a verdict. Or maybe it did. 12 Leaf owners did assemble one night to prove Nissan wrong.

Three weeks ago, Nissan’s Executive Vice President Andy Palmer was quoted by Australia’s Sydney Morning Herald as saying that “we don’t have a battery problem” and that the battery level display is faulty. Enraged, the Arizona Leaf owners set up a massive test, and published the results at InsideEVs.

12 Leafs with odometer readings as low as 2,500 miles and as high as 29,000 miles assembled at night at 7755 South Research Drive, Tempe, Arizona. The location was chosen because it has a DC Chademo fast charger, and two J1772-2009 EVSE charging stations. From there, they did set out to drive the Leafs until the battery runs out, or more exactly, until the Turtle in the display strongly recommends to get off the road. They even had a small fleet of dollies and a flatbed truck to collect the exhausted Leafs.

The results of the test appear to support the group’s claim that the Leaf’s batteries degrade much faster than they should, at least in the hot climate of Arizona. A Leaf with 29,000 miles on the clock did last only 59.3 miles during the group’s test, a nearly 30 percent degradation from the 84 miles the group says a new Leaf should get. A Leaf with only 2,500 miles on the meter did last nearly 80 miles.

The test was professionally set up, VERY detailed description here. The group also measured the charge indicator, and found that in most cases, the instrument low-balls the available charge. Says Tony Williams who spearheaded the effort , and who had done an all-electric Canada to Mexico trip in a Leaf:

So, Andy Palmer was right… they have poor instruments. But, he was wrong about the batteries. It was sheer stupidity to tell this group of owners that the batteries are ok. “

We talked to Nissan’s General Manager of Global Communications, Jeff Kuhlman, in Yokohama. Kuhlman praises the affected owners who “are very knowledgeable, some are engineers themselves.”

He denies that Nissan has come to a conclusion on the matter: “We cannot give you a final analysis, because there simply is none available yet.”

Seven affected Leafs were inspected by Nissan , and subsequently returned to their customers. Nissan did a full data download on all units.

“The data are with our technical team in Yokohama, and they are still analyzing them,” says Kuhlman. “Once they have finished their analysis, the owners will be contacted first, and we will discuss with them what needs to be done.”

Kuhlman expects the verdict to be available “within days.”

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33 Comments on “The Case Of The Missing Bars: Leaf Owners Stage Massive Test To Prove Premature Battery Aging...”

  • avatar

    Did these people not do there “Homework” before purchasing the “Leaf”surely there must have been some indication of this possible defect?

    • 0 avatar

      So, you’re setting up a strawman, or at least throwing a red herring out, in an attempt to argue against the fundamental, black or white tenet that consumers should NOT be allowed to rely upon the statements, representations and other implied or expressed assertions regarding the standards and specifications of their vehicles and that of the components, such as electric vehicle batteries, that go into them?

      There’s a REALLY basic fact here: Corporations should accurately describe the specifications, capabilities AND limitations of their products, and where a corporation fails to do so, whether intentionally or by mistake, corporations need to do whatever is necessary to either fix the discrepancy or, if that’s not possible, provide the consumer with other satisfactory relief.


      Isn’t this the MINIMUM that should be expected of a vehicle or any other manufacturer or retailer?

    • 0 avatar

      I for one did tons of “Homework” before purchasing my Nissan Leaf. I figured they were going to have issues with battery life in AZ since every other 12V car battery I’ve owned has died before the warranty. I was hoping that this new generation of Lithium Ion batteries would be better. Check out my site to learn more about my issue.

    • 0 avatar

      Getting information on this topic is not as easy as it seems. I have had some problems with my hybrid’s battery and have come to find out that many manufacturers simply do not provide warranty terms that cover capacity loss. While I am still performing research, what I have found out thus far is available at:

      Please note number of times that I have to go to a dealership to find the information. This is the main reason why my research has not been completed.

  • avatar

    This one is going to leave a mark.

    At present the owners will take a bath if they dump their cars. I hope most people leased.

    I would guess most people in the market for these things do a lot of reading and have found or will find about this.

  • avatar

    Wasn’t there quite a lot written about how Nissan “cut costs” on battery thermal management compared to the Chevy Volt by opting for passive air cooling rather than full-on HVAC temp management? Is anyone surprised that an air-cooled battery degrades quickly over a summer in Arizona?

    • 0 avatar

      Armchair engineers leveled the charge about ‘cutting costs’ by using a passive cooling system.

      If you’ve ever designed a cooling system, you’ll find it’s much more difficult to design an ambient-cooled system than an actively-cooled one, because you must build in higher margins.

      So the passive system will have lower product costs, but the active one will have lower development costs.

      In this case, heat may indeed be a problem, but so could extremely cold climates.

      The real issue isn’t so much the climate or the battery cooling system – it’s the lithium ion cell technology itself, which is very sensitive to a variety of abuses, temperature being only one of them. Overcharging is a big no-no, but I’d assume the Nissan charging system prevents this. Rapid cycling is another no-no, as is deep discharging. Again, Nissan should have measures in place to deal with this.

      • 0 avatar

        I disagree on active/passive cooling (and the reverse – heating in some cases). I have designed cooling before. I am pretty good with batteries, too.

        Passive needs ambient extremes to be known and worst case thermal output/stress/cycles/song and dance, then you solve for that stuff and see if it matches up. It the numbers don’t work, passive cooling is out totally. Surface area is easy. If you force Passive when the numbers say otherwise, well, what would you expect to happen? You can do passive in some forms – even in Arizona but it’s a neat trick and other options look more favorable. Easy to get it way wrong if you aren’t careful.

        Active cooling is a mess. You have to account for overcooling, partial failure, full failure and a gazillion things that can go wrong. Ambient temperatures are even more constraining sometimes. Sometimes you have way too much and sometimes you have way too little. Condensation. Bearings on spinny things. Power sources for the whole works, coolant sometimes, – and the ultimate rabbithole, a failsafe to prevent catastrophic failure if active cooling goes down. Now are you going active/active or active/passive with that failsafe?

        In most of the stuff that I mess with, I do passive, or basic air cooled active. Caveman simple. Throw surface area at it, call it good.

        Sometimes an active failsafe on a passive system is also the right solution, if you like a good challenge. Usually the active backup needs to have some real beans, more so than you might think to truly save you.

        Lets not forget that the entire premise is alarming. Any battery that truly needs any significant degree cooling is one scenario I don’t want to be anywhere near. Especially lithium ion. Serious buisness. What are they doing to those poor batteries? Can I stand behind that concrete wall over there?

      • 0 avatar

        I also have to wonder what extreme changes in temp do to the system. The desert is known for cool nights and hot days. Add the battery discharging during the day, the commute home is going to be very hot with the battery. Park at night, and the temps will drop.

        Active management isn’t just for cooling the battery. It tries to keep it within a range of temps that are optimal for the battery.

        But, I have to disagree with you saying that this is a problem with lithium ion cell technology, sensitivity to temp. Nissan knew this going in. Nissan designed the battery pack and temp management system. Apparently, in AZ, it was the wrong move.

  • avatar

    Shoulda bought a Volt. My opinion, anyway…

    But…I suppose if where you work has charging stations, then why not? An all-electric Leaf might make sense.

    • 0 avatar

      True on the Volt. But if I was a owner a Volt and the battery portion of the car did this, I’d be up GMs and the dealers backside on this.

      At least you could still drive the Volt whereever you needed to go.

      I pity these people who bought a Leaf and their normal range between charges was sufficient to get where they needed to be and then back to a charging station without a bunch of hassles. Say you have a Leaf and back and forth to work leaves you with 10-15 miles in the battery tank. But, there’s no charging at work. The Leaf then drops the 10-15 miles. You now have a paperweight that sits in the driveway.

  • avatar

    I guess I need not re-publish a list of 16 items on TTAC that shows EV’s to be at best insubstantial with current technology. This little “surprise” with the Nissan Leaf is no surprise at all. EV’s will do best in moderate climates that are neither too hot nor too cold. Good for shopping in inner cities with lease arrangements, and as a “second” vehicle. It’s kind of a “goldilocks” product. Sorry, I guess I am growing weary of the EV façade, as we “discover” one problem after another.

    If we want greatly to increase MPG, use diesel. (But even gasoline-ICE cars can now get > 40 mpg.)

    If we want to transition to much lower emissions: expand infrastructure and use CNG. Already doable.

    If we want to achieve zero-emssions: develop infrastructure and use Hydrogen – in both FC’s and ICE. Shown to be realistic with the Honda Clarity and BMW Hydrogen 7 vehicles. Obviously Needs investment.

    This really isn’t rocket science.


    • 0 avatar

      I agree about moderate climates. Anyone try to use a D-SLR in the winter time? Those things are battery hogs, and cold weather use sucks the battery drive in a short period of time.

      Kind of hard to sell a car that can only be used in certain states.

      I’d like Nissan to say, that the warranty only is good for Washington, Oregon, Northern California, North + South Carolina, Maryland + Delaware. Use of a Leaf in other states voids the warranty, because the batteries won’t hold a charge in any other state because of the extremes in hot and cold temps.

  • avatar

    Could it at least be partially a signal problem? The readings were taken from dashboard instruments. Did anyone physically test the batteries with a separate device?

    • 0 avatar


      Good suggestion. That should have been done anyway. However, it is unlikely to have been an incidental signal problem over 12 vehicles; and even it was, then that also represents a significant issue with the electronic monitoring in the Leaf and its “confidence” factor. When the “turtle” appears, you’re done, regardless.


      • 0 avatar

        When the turtle appears there is a fair amount of distance left, but by continuing to drive a significant distance you do so at the risk of reducing the life and thus future range of the battery. That cushion between when the turtle pops up and when the vehicle will shut down was done on purpose.

      • 0 avatar


        So, what other reproducible endpoint would you choose for their experiment, and still allow the vehicles to recover unharmed from it?


  • avatar

    Leafs? Leaves?

  • avatar
    Carlson Fan

    “Wasn’t there quite a lot written about how Nissan “cut costs” on battery thermal management compared to the Chevy Volt by opting for passive air cooling rather than full-on HVAC temp management? Is anyone surprised that an air-cooled battery degrades quickly over a summer in Arizona?”

    What I have read is that Nissian supposedly had some type of new technology in the battery that kept it from getting hot during use(discharge) which is why they went with the passive system.

    “Those things are battery hogs, and cold weather use sucks the battery drive in a short period of time.”

    True, but unlike an ICE where the energy is lost, that doesn’t happen with a battery in an EV. If a Volt only goes 20 miles on a full charge due to the cold, it will also charge back up in the 1/2 the time. My ICE Toyota truck would sometimes see a 30% reduction in range during a Minnesota winter where I was making a lot of short trips.

    • 0 avatar

      No one of the reasons that an EV has reduced range in the cold is beacuse most people use the heater and/or defroster which uses up a portion of the charge reducing that avaialble to propel the car and thus it’s range. So when all is said and done range loss does not equate to shorter charging times.

  • avatar
    Polar Bear

    Volkswagen would be happy to sell a 60 mpg car if only Americans had wanted it. It is the 1.6 turbo diesel Blue Motion Golf available in Europe. It looks and drives like a normal car, it will “recharge” in two minutes and you can drive it as far as you want.

  • avatar

    Leafs=Losers I cannot figure out why anyone would pay 30K plus to be held hostage to such a limited range of travel. If there were a need to travel out of town for an emergency, i.e. 250 miles, you can’t do it. I can see buying a Prius or better yet a Volt, but this car. How stupid can you get? Here’s your sign!

    • 0 avatar
      el scotto

      A Leaf is a niche second car for urban/semi-urban dwellers with a plug in. Old GF and I lived inside the beltway in DC. She had a nine mile round trip commute. She took an Alexandria VA and a DC bus to work; the schedules just worked out that way. Her work pays for her electronic subway/bus pass. She’d gladly trade in her electronic subway/bus pass for a Leaf. Old girl likes her cars, had an Alfa and a GTI back in the day. Currently drives a it’ll get the crap beat out of it in DC parking lots I’ll trade it in if it ever dies Corolla. Demographics factor in too. She’s the highly educated one of one of the couples in Whole Foods on the weekend.

  • avatar

    Nissan really blew it on this one – if they tick off the EVangelists out there (their best field salespeople), it’s over . . .

    If there is a problem, come up with a plan to deal with it: possibly replacing batteries and/or compensating existing owners in the short term while working on longer-term solutions back at the lab.

    • 0 avatar

      Agreed on this. I’m not an EVangelist, but I was seriously considering a Leaf as a replacement car someday, since I’m mostly a commuter.

      With my short commute (9 miles), I could tolerate a lot of battery degradation. But this test by knowledgeable owners puts Nissan in a very bad position, on a vehicle they’re already struggling to sell.

  • avatar

    Until The Miracle happens and someone stumbles across a robust, high energy density battery chemistry, a hybrid or high efficiency ICE is a better deal.

  • avatar

    Nissan really, really, screwed this up. You can’t change the law of physics. Battery capacity is impacted by ambient temperature. Nissan does not provide cooling for their batteries, and only provided heating optionally in the first model year. Great way to cut corners as the heating/cooling systems are expensive and add weight (which hurts range) but the impact is very clear. The batteries degrade quickly.

    Everyone else, from Ford, to Toyota, to GM, to Mitsubishi, to Tesla, to Fisker to…. got it right.

    There is no clean easy fix to this issue long term, Nissan is going to be buying customers a lot of batteries, and a Leaf with 80K to 100K miles is going to be worth – squat.

    Oh well, they are cheaper than a Volt.

    • 0 avatar

      With Nissans recent styling, the Juke, and their other blunders I’m starting to wonder why they’ve screwed up the way they have.

    • 0 avatar

      Nissan will be paying for a lot of batteries because they are supposed to come with an 8 year 80k warranty I think.

      • 0 avatar

        The warranty does not cover gradual loss of capacity.

      • 0 avatar

        No capacity warranty but the way some of these batteries are going (in Arizona) they will become warranty items with 3-4 years of use once the car refuses to accelerate.. even worse if the owner has a longer commute than normal and needs the full 80 mile range daily. There are 400 Leafs in Arizona and it costs $5000 for a new battery, you do the math. Nissan is probably waiting for the Tennessee battery factory to gear up in a couple of months, presently they are made in Japan.

        There is a Leaf in Washington at over 50k miles and estimated to be around 10% degradation.. battery capacity is hard to measure because anything affects range, including tire thread depth.

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