All The Results From Independent Test Of Nissan LEAFs With Lost Capacity. Not All Instrument Failure

2 years ago by Tony Williams 81

Nissan LEAF Range Autonomy Demonstration

Nissan LEAF 'Fleet' At Dawn, Ready To Start Test

The Nissan LEAF electric car was introduced to the world as a mass production vehicle during December 2010. Almost 40,000 have been sold around the world in the short time since then, with well over 10,000 sold in the USA. Unfortunately, a percentage of those USA cars that are operated in hot climates, such as Phoenix, Arizona, and the state of Texas, have experienced accelerated losses of the vehicle’s range autonomy, when compared to its performance when new. The phenomenon is not relegated solely to areas of extreme heat; many LEAFs now in moderate temperature areas of California have also experienced significant range autonomy reduction, however not yet to the extent of those cars exposed to Arizona and Texas heat.

 

When customers have complained, thus far Nissan has claimed that any reduction in range is “normal”, regardless of how much that capacity loss is. Battery issues that are covered under the warranty include “power” to accelerate, or a specific battery failure or abrupt change in the battery performance. Nissan specifically claims that they do not warranty capacity. Nonetheless, in late 2011, Nissan did exchange at least one battery of an Arizona LEAF when its owner complained of reduced capacity. That replacement battery also began degrading recently, and the owner subsequently relinquished the car as a result.
UPDATE (Sept 22, 2012): Nissan has responded to capacity loss of LEAFs in heat affected areas, and this independent test. Read that story here.

Staging The Cars The Night Before The Test

In July 2012, with increasing numbers of LEAFs reporting battery capacity problems, Nissan took approximately one half dozen Phoenix area LEAFs whose owners had complained of reduced range and lowered battery capacity (as indicated by the vehicle’s dash mounted instrument) to its corporate testing facility in Casa Grande, Arizona.

 

All of those cars have since been returned to their owners, however none of those returned cars had reported any positive change in actual performance by their owners. One car’s battery capacity instrument was reset by Nissan to a “like new” battery indication of 12 of 12 instrument segments, from its previous 10 or 12 segments (10 segments indicates 72.5% – 78.74% battery capacity per Nissan documents). This same car once again lost the 12th capacity segment (with 11 of 12 remaining) on Sunday, September 16, 2012. Of the cars sent to Casa Grande, none have been reported to have been driven by Nissan more than a few dozen miles while at the testing facility.

 

One prominent Nissan executive is frequently quoted saying that the LEAF should have 80% capacity in 5 years, and 70% capacity in 10 years, and in fact, he specifically states during a Nissan produced YouTube video that those figures are considered “gradual” loss of capacity. Earlier this month, an Australian news agency reported that a Nissan Executive Vice President with specific experience with the LEAF, Mr. Andy Palmer, said that there is “no problem” with the LEAF battery, and that the any customer complaints were merely the result of instrument problems.

 

In response to this revelation, a group of twelve Nissan LEAFs were independently gathered on Saturday, September 15, 2012 in Phoenix to put this statement to an actual range test; driving a fully charged LEAF in controlled conditions to measure how far they could actually go. Any battery test (or allegation of good batteries) is meaningless if the car can’t actually do the job it was designed to do. In the USA, that job is advertised as traveling “100 miles” (161km), and even further, 200 kilometers (124 miles) in Japan. Clearly, if Nissan truly felt that the batteries were performing as designed for the customer cars they tested at Casa Grande in July, they could have simply verified that at the private, purpose built test track at their disposal there. The actual driving portion of the test would have taken about 90 minutes per car, but they chose not to. Four of the twelve cars in Saturday’s Phoenix area test were previously at the Casa Grande test facility in July.

2:44am, just 25 minutes before I launched my car, "Black782", on the test course. Five of us stayed up all night, and one of those pictured doesn't even own a LEAF anymore!

 

A staging area was selected at 7755 South Research Drive, Tempe, Arizona, which has one DC Chademo fast charger, and two J1772-2009 EVSE charging stations. Equipment was used to split the latter two stations into four total EVSE’s. This staging site was conveniently located within 0.3 miles (0.5 km) from the main highway. The route traveled was highway 101 north for 5.2 miles (8.3 km), then highway 202 west which becomes highway 10 west. Each car continued west until a predetermined course reversal point, and then returned to near the starting point. This route is largely level and with dry asphalt or concrete roadbed in excellent condition.

 

Turn around points were determined based on predicted range of each car after considering each car’s battery capacity meter and viewing the car’s report of stored watt-hours with additional equipment. The following round trip distances apply at these course reversal exits on highway 10. The total distance measured is from the staging area and ending on the 101 highway southbound at the East Elliot Road overpass at highway 101. The percentages are the battery’s stored available energy:

62% – 52.3 miles (83.7 km) – Exit 136, 75th Avenue
64% – 54.3 miles (87.4 km) – Exit 135, 83rd Avenue
67% – 56.3 miles (90.6 km) – Exit 134, 91st Avenue
69% – 58.3 miles (93.8 km) – Exit 133a, 99th Avenue
74% – 62.3 miles (100.3km) – Exit 131, 115th Ave / Avondale Boulevard
79% – 66.3 miles (106.7km) – Exit 129, Dysart Road
81% – 68.3 miles (109.9km) – Exit 128, Litchfield Road
85% – 72.3 miles (116.4km) – Exit 126, Pebble Beach Parkway / Estrella Parkway
91% – 76.3 miles (122.8km) – Exit 124, Cotton Lane / highway 303
98% – 82.3 miles (132.5km) – Exit 121, 195th Avenue / Jackrabbit Trail
101%- 85.1 miles (136.9km) – Exit 120, Airport Road / Verrado Way
109%- 91.5 miles (153.0km) – Exit 117, Watson Road

 

The dash display of Battery Capacities per Nissan documents are as follows:
53.75% – 59.99% – 7 segments of 12 illuminated
60.00% – 66.24% – 8 segments of 12 illuminated
66.25% – 72.49% – 9 segments of 12 illuminated
72.50% – 78.74% – 10 segments of 12 illuminated
78.75% – 84.99% – 11 segments of 12 illuminated
85.00% – 100.0% – 12 segments of 12 illuminated

 

The backup routes, in case of highway closures, crashes, etc., were either a 40.4 mile (64.6 km) “RIGHT LOOP” consisting of highway 101 North, 60 East, 202 South and then West, then 101 North again, or a 21.8 mile (34.9 km) “LEFT LOOP” via 101 North, 60 West, 10 South, 202 East and returning to 101 North. None of the cars took either of these latter routes. The only highway closure was Cotton Lane exit on highway 10.

 

The course was driven at 100 km/h as measured by the LEAF’s onboard GPS (62 mph ground speed, 64 mph indicated speed as displayed on the LEAF’s speedometer) with the cruise control engaged. It was estimated that this speed would yield a target energy usage rate of 4 miles (6.437 km) per kWh without climate control. Based on Nissan’s published official range data below (from Nissan Technical Bulletin NTB11-076a), it was determined that a new car would travel 84 miles (135 km) until “turtle” mode (a reduced power mode to safely get the vehicle off the road before the battery disengages power altogether). This data is consistent with extensive publically available independent testing.

The following is the official U.S. government weather reports, during the period of active vehicle testing, from nearby KPHX airport from 2:51am (0951Z) until 9:51am (1651Z):

Time (UTC – GMT – Zulu) Barometric Pressure (mbar) Temperature (degrees F/C) Dewpoint (degrees F) Relative Humidity (%) Wind direction (degrees magnetic) @ Wind speed (knots/meters per second)
0951Z 1018.29 78.8 / 26 46.4 31 080 @ 6/3
1151Z 1018.29 78.8 / 26 44.6 29 070 @ 8/4
1251Z 1018.29 78.8 / 26 44.6 29 060 @ 12/6
1351Z 1018.63 78.8 / 26 42.8 27 070 @ 15/8
1451Z 1019.96 78.8 / 26 44.6 29 070 @ 12/6
1551Z 1019.30 80.6 / 27 42.8 26 080 @ 13/7
1651Z 1019.98 82.4 / 28 42.8 24 070 @ 10/5
1751Z 1019.98 84.2 / 29 42.8 23 070 @ 10/5

 

Air Density Calculation
Elevation: 1135 feet (346 meters)
Air Temperature: 80F (26.6C)
Altimeter Setting: 30.09 inches Hg (1018.5 hPa)
Dew Point: 43F (6C)

Density Altitude: 2685 feet (819 meters)
Absolute Pressure: 28.864 inches Hg (977.46 hPa)
Air Density: 0.0706 lb/ft3 (1.132 kg/m3)
Relative Density: 92.38%

Some LEAFs (shrinks) Took Some Damage Over The Course Of The Test

All LEAFs in this test had the front bumper tow hook installed. All trip odometers, miles/kWh, average speed, timers, etc., were reset. Headlights were on, climate control off and tires set to 36 pounds per square inch (2.48 bars) pressure. All assigned routes were programmed into each navigation display.

 

Each car had a stored energy display meter (Gidmeter) installed. A new LEAF in optimum condition will show 281 units reported by the LEAF’s automation, for a total of 281 x 80 watt hours per unit = 22.48 kWh stored in the battery. This value, referred to in the LEAF community as “Gids”, is alternately displayed as a percentage of 281 (281 would equal 100%). The LEAF battery has an advertised capacity of 24 kWh.

 

To help keep track of each of the cars, the last three digits of the LEAF’s serial number were affixed on the right top front of the windshield and left rear top of the rear window. Stickers were added to the dash to remind the drivers not to use climate control (or even turn the fan on, as that powers the climate control) and for other safety related functions. Lighter weight driver’s cars had ballast added to match heaviest drivers. The front windows could be either closed, or up to 2 inches open. Rear windows were no to be opened. Most drivers were not the owner of the car they drove, but instead drove another car. Every car was charged the night before, and left outside to be exposed to ambient air for a minimum of 4 hours (most cars well exceeded this). A secondary goal to this was to allow time for the LEAF’s automation to properly balance the 96 cell pairs.

 

Keeping "Controls" On The Test

At the start of each car’s test, the driver recorded the starting position GPS coordinates, time from the GPS clock, battery pack voltage (typically 393.5), the “Gid” percentage, Fuel segments observed (in every case, 12), battery capacity segments (varied from 8 to 12, depending on which car) and battery temperature segments displayed (6 in every case, indicating temperatures between approximately 50F (10C) to 100F (38C) per Nissan documents).

 

Each car had a nine page comprehensive checklist and information package. Finally, the “Distance to Empty” meter readout was recorded. This is largely for entertainment value, as the meters are known to provide such wide variations from actual expected performance that it is affectionately known as the “Guess… Oh… meter”, or “GOM” amongst LEAF owners.

 

At the conclusion of each run, after the car was safely off the road, and awaiting one of five recovery vehicles used (four rental car dollies attached to gasoline tow vehicles, and one flatbed truck), GPS coordinates were once again recorded, the time from the GPS clock, battery pack voltage, Gid percent, fuel bar segments illuminated, battery capacity segments illuminated and temperature segments illuminated. Finally, the trip odometer mileage and the dash readout of miles/kWh were recorded.

 

Following is the performance of each car:

 

Conclusions and Opinions

My Car Is Loaded, Then Off To Brunch Off to Brunch And An Almost 400 Mile Drive Home

The Nissan LEAF has only been on the world stage for about 21 months. Many in the automotive battery world expressed concern over Nissan deploying this chemistry in hot climates without a means to regulate battery temperature long before a single LEAF was built. Only LEAFs in very stable and mostly cool places like the England, the San Francisco peninsula, Seattle, Portland (which this summer had unseasonably cooler temperatures, while the rest of the USA baked) have been largely immune from degradation. Even San Diego, where I live, has reported cases of battery degradation.

 

Both of the 2012 cars (my car was one of them) in the test were replacements for previous LEAFs that suffered battery degradation. Nissan offered no assistance or consideration for the previous cars shortcomings for these new leases. Battery reports issued by the dealers were consistently “5 of 5” stars.

 

One of the many challenges in this endeavor was finding a “control” car that could actually test out at 100% battery capacity. LEAFs sitting on dealer’s lots in Phoenix, and other hot places, usually with very high states of charge, are in a very difficult situation for the long life of the battery. None of the cars in our group could even come close to 100%, and that includes a car with both of the 2012 model cars, both built in April 2012; one with 2500 and the other 7000 miles.

 

I planned, and completed a promotional trip from Mexico to Canada, “BC2BC”, in June 2012 with my Nissan LEAF. However, my first car could not complete the trip as planned, due to its reduced range capability, so I leased my current LEAF, built in April 2012 and took delivery at the end of May. Now, with 7000 miles (11000 km), and only 3 months of actual use, this car could not complete the trip that it did in June. During the BC2BC trip, several times I arrived with 4%-5% capacity remaining, which means today, just a few months later, I would come up 4%-5% short. This car has never been exposed to the heat of Phoenix, although it was 104F (40C) in San Jose, California the one day that I was there.

 

My car, Black782 and the BC2BC car, tested at about 89% of available battery capacity, and drove to 91% of available capacity. That’s within 2% between the two figures and a reasonable error. Other cars had HUGE differences between the instruments and the actual range performance. 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. A California study showed that about half the owners have post-graduate degrees, and many of those are in technical fields. A significant percentage have owned electric vehicles prior to the LEAF, and many, if not most of those who have traded their faulty LEAF have gotten another electric powered car, like the GM Volt, and like me, another LEAF.

 

Nissan – Renault chairman Carlos Ghosn announced Friday that 2013 LEAFs would have a new battery design. One has to wonder if this is merely public relations move to deflect from the current battery woes, or if a real new battery will emerge. Then, we have to wonder if they employed the same testing that the current batteries were exposed to. Nissan really needed to get the LEAF right the first time, and they did an absolutely incredible job overall. I tell everybody know that it’s a fantastic car with one fatal flaw.

 

I would like to thank everybody who helped make this test a reality, and a fun experience. There are literally dozens who participated. Four of the cars were damaged during loading on the Uhaul rental tow dollies, and many folks have expressed interest in donating money to offset costs and damages from this event. You’re welcome to email me at DriveGreen@QuickChargePower.com and I will let you know how to send a donation. All monies will first reimburse the owners of damaged cars (I’m not going to fix mine, however, so I don’t need reimbursement), and then any donations above that will go into the non-profit company that I founded to provide electric vehicle charging in California. I won’t personally take any donations.

 

UPDATE (Sept 22, 2012):  Nissan has responded to capacity loss of LEAFs in heat affected areas, and this independent test.  Read that story here.

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81 responses to "All The Results From Independent Test Of Nissan LEAFs With Lost Capacity. Not All Instrument Failure"

  1. Jay Cole says:

    I just wanted to be the first to thank Tony for doing this, as well as all the people who volunteered their time and LEAFs. A ridiculous amount of effort and work went into this.

    Jay

  2. brg2290 says:

    Yes, a big thank you to Tony!!, the core group that undertook the testing!, and the mynissanleaf community at large. I’ve lurked on MNL, posted a few questions, and in general tried to become informed about the generalities and specifics of Leaf ownership, but a combination of relatively high prices and newness of the technology has kept me on the EV ownership sidelines. All I can say is thanks to all the early adaptors…those of us on the sidelines but interested in EV’s and EREV’s owe you a debt of gratitude. I’ll be watching closely to see if the claimed Nissan 2013 battery improvements withstand verification, but I’ll be watching even closer to see how Nissan treats their 2011-2012 Leaf customers as these test results become more widespread. In essence, it seems Nissan used them as beta testers, and I’d like to see the owner’s concerns address by Nissan, rather than disenfranchising their most stalwart supporters.

    1. Jay Cole says:

      Yes! I’d like to also add my thanks to the MNL community, and Mike who owns the forum for bringing everyone together so Tony could connect with so many like minded individuals.

      If anyone wants to read how all this came about from start to finish, here is the thread at MNL that got it all started (and is now about a bazillion posts long, lol)

      http://www.mynissanleaf.com/viewtopic.php?f=30&t=9917

      If you own a LEAF, or are thinking about a LEAF, you need to go there, sign up and get involved with the community…there is no better resource!

  3. Great job Tony. This is very unfortunate. I know Nissan hasn’t been very helpful, but I can only imagine at some point soon they will have to intervene and do something for the folks that have this problem. The scope of this problem is going to only grow as time goes on.

    I can tell you with certainty I have not seen any battery degradation nearly like this in my EV experience. I don’t live in such a hot climate as Arizona, but I did drive my MINI-E 73,000 miles and recharged it 1,390 times in 31 months. I have detailed data logs that recorded every mile I drove and at the end my range was diminished less than 10%. The MINI-E also had a primitive passive thermal management system and my battery temperature was above 110 degrees frequently in the summer and below 40 degrees all the time in the winter.
    So far my ActiveE has been great in the 9 months I’ve had it. I already have 25,000 miles on it and have charged it 545 times. The active thermal management has kept the battery below 105 even on the hottest days and with hard driving. actually I’ve only seen it break 100 degrees a couple times so the system is definitely working and should help fend off degradation like what seems to be going on with the LEAF.

  4. Stuart22 says:

    I’ve long been critical of Nissan and especially Ghosn, yet always felt admiration for the rugged devotion of LEAF owners. This article confirms my feelings. Nissan better quit trying out for the starring role in “Who Killed the Electric Car II” and start taking care of the people who put their faith and trust in them.

  5. Kelly Olsen says:

    This is sad to see and disappointing that Nissan has not taken the high road. I hope they change their attitude and realize that the early adopters need to be seen as leaders and should be treated with respect. You invested money in good faith into an unproven product and in return you deserve loyalty and cooperation.

    The people involved in replying to this should be removed from their job and located someplace else within the company. They need to take responsibility and work hard to fix the problem and make all of the owners completely happy and satisfied. Anything else is unacceptable.

    I plan on getting a 2013 LEAF, but this makes me a bit wary.

    1. Kelly, you should write Nissan and tell them you have been planning on buying a 2013 LEAF, but will base the decision on how they treat their existing customers that have been sold defective battery packs. If enough people let Nissan know they will lose future sales if they don’t act quickly and decisively to correct this issue, perhaps it will wake them up.

    2. Bonaire says:

      Kelly, At a minimum, wait for the Gen-2 batteries if you live in a warm climate. Also, a Leaf in a cold climate does have another shortfall – lower mileage in the winter (as all EVs do). Give it some time, maybe take a look at other offerings from other companies, etc. Could you use a Volt for longer drives? Maybe a Chevy Spark EV when they come out (similar mileage to the Leaf)? Ford Focus EV (An American-made EV versus the prior two I mentioned). Ford C-Max Energi perhaps? Lots of choices to come in this area.

    3. MrEnergyCzar says:

      The Ford Focus EV has greater EPA rated EV range and the batteries are liquid cooled….

      MrEnergyCzar

      1. JPWhite says:

        I trade as soon as the Focus EV comes on the market in TN except for one thing. No quick charge.

        1. MrEnergyCzar says:

          It’s on-board charger is 6.6KW which is 20 miles of charge per hour.

          MrEnergyCzar

  6. You're joking? says:

    You’ve got to be kidding don’t you….

    The ONLY instrumentation you’ve used is… the vehicles own dashboard and a GID meter that reads the same CAN data signals as the dash instruments?? Have you recorded any independently instrumented data at all? No attempt to identify any faulty cells? Have any of you independently measured any voltages either inside or outside the pack? No attempt to have a suitably qualified 3rd party remove a pack and actually cycle test it?

    The fact is none of this data is independently verifiable at all!

    If you claim to have recorded pack voltage at the end of each run, you conveniently haven’t included that data in your little chart! ..

    You’re trying to bring Nissan’s 100 miles range claim into question, yet you’ve chosen to drive the vehicles at a constant 100 km/h on a level road, hardly conducive to maximize EV range is it!

    This reminds me of that dope who bricked his Tesla then ran a smear campaign to try to shake down Tesla…. that really went well from memory!

    1. Hi Gary! I wondered how long before your “special” vitriol would surface here. Because you are a loose cannon with a trigger finger, I will offer a bit of advice; when you vitriol crosses the line to liable and slander, you just might be in for a rude surprise. Keep that thought in your back pocket.

      Since we already how thick your brain is, I won’t direct my comments for your consumption, but that of the general reader.

      First, no attempt was made to “maximize” the EV range. The test demonstration was COMPARING cars in like conditions, and that includes driving a uniform speed. That speed was 100kmh (about 62mph).

      Since this was a RANGE test, and not a battery test, we made no attempt to fix Nissan’s vehicles. Additional battery data was taken that wasn’t published, but again, that’s not what we were comparing. We won’t be having 3rd parties to test the pack, because we don’t know what the problem is. Maybe the brakes are locking up? Who knows? Maybe pixy dust got on all the roads in Phoenix? We’re not repairing cars, or sweeping away pixy dust, or quantifying a specific problem beyond the simple fact that they don’t drive as far as when new.

      Tony

    2. >>>>The ONLY instrumentation you’ve used is… the vehicles own dashboard and a GID meter that reads the same CAN data signals as the dash instruments?? Have you recorded any independently instrumented data at all? <<<<<

      Yes, we of course gathered data external to the cars instruments. The distances were measured with both the LEAF's trip odometer, GPS coordinates, and Google maps measurements.

      The Gid readings are only included in my report to help folks with a bit more brain matter upstairs to help them understand why. This wasn't a LEAF Gid comparison contest, and I knew that if I did include it, you'd bite like trout in a cool mountain stream… maybe it's time to go fishing?

      I'm surprised that you haven't commented on the fact that NO car went 84 miles. Honestly, that's a serious omission in the test… comments? (ya, that's fishing, folks!)

  7. MrEnergyCzar says:

    Wait a second… The Leaf battery isn’t warranted for battery loss beyond certain thresholds like the Volts? How can that be? Even my solar panels are warranteed to produce 80% of their original power after 25 years. Liquid cooled is the way to go.

    MrEnergyCzar

    1. No, there isn’t a warranty for battery capacity at all. For folks who want to own a LEAF today, I recommend leasing it and fully understanding that if you’re in a hot area, the range will more quickly decrease than it would in a cooler area. That’s just a fact. The battery has no cooling system at all, not even an internal recirculating fan as the prototypes had.

      If you need the car to go that mythical 100 miles that Nissan advertises, first know that it never really went 100 miles for the typical US consumer. When new, it can go down a level freeway with a battery at 70F temperature or above, at 60-65mph, with no heater or air conditioner, for a bit over 80 miles. That will give you an economy of about 4 miles per kWh stored in the battery.

      Should that battery be cold, the stored energy is significantly reduced. Over time, the battery will normally lose capacity, and the intense heat of places like Phoenix merely amplifies that degradation.

      EPA rating for the LEAF is 73 miles, but as you see in the test, the cars drove between 59 and 79 miles in like conditions, which included about 80F temperature of the batteries. We could conduct the same test at 30F, and lose another 10% in range. If you run the heater, the range will drop significantly more in addition.

      Like I said in the article, it is a GREAT first try at a mass production EV. There are just a bunch of limitations that the consumer needs to know, and a huge problem if you live in hot areas.

      Tony

      1. MrEnergyCzar says:

        Great test Tony. Thanks. Since there is no warranty for battery capacity, Nissan saying the battery should be at 80% after x years doesn’t mean anything. If all Leafs got 45 miles range, but normal power, they aren’t covered because it isn’t abrupt?

        MrEnergyCzar

        1. That’s right… they could say any number, and it’s still not covered for warranty. Now, that doesn’t mean some folks won’t be successful with tort claims, or their state’s attorney general, or Lemon Laws, etc.

          But, who wants to buy a car with a known issue that you’ll have to fight later? We will continue to pressure Nissan from every angle to turn this ship around, but there are no guarantees.

          1. MrEnergyCzar says:

            Hmm, pressure. Just have those Leaf owners make youtube videos showing what is going on with their Leaves….if they all did that, and got them up on youtube, one of the videos would probably get picked up by the major media outlets…. Nissan would spot them earlier is the point….

            MrEnergyCzar

            1. Marc Lee says:

              Yes the local News Channels have done stories, and apparently more are planned.

            2. Nehemiah Spencer says:

              The double-edged sword to this (unless very articulately handled) is that the Leaf’s poor design issue could be used to slander all EV’s …

              This risk must not be taken lightly. Again: it must be made (almost as a primary point) that other EVs like the Volt, etc, have active thermal management systems, are performing better than expected, and have warranties for a certain battery percentage after a certain number of years.

              1. Russ says:

                The Volt isn’t an electric car. It’s a plug-in hybrid.

                1. Stuart22 says:

                  Well, my Volt has been racking up all its miles on electricity for the past week and a half, so don’t tell me it isn’t an electric car.

  8. GeorgeS says:

    could one of you guys bring me up to speed.
    What is the warranty?
    Is this 80% in ? years just an empty promise with no warranty?
    I keep hearing there isn’t one yet it sounds like one of the guys got their car replaced.
    Why didn’t they just replace the pack.

    Thx,
    GSB

    1. MrEnergyCzar says:

      George, are our Volt batteries warranteed to meet certain pre-determined milestones based on mileage and age?

      Thanks
      MrEnergyCzar

    2. Nehemiah Spencer says:

      Leaf’s warranty is meaningless.

      1. Nehemiah Spencer says:

        Volt’s warranty actually is meaningful.

        1. The Volt warrantee is 80% capacity (I think) because it is an oil burner car, and if the battery degraded further, the oil burning engine would have to operate more, hence more pollution. The U.S. EPA won’t allow that.

          So, the Volt must comply with rules (like the 8 year battery warrantee) that the LEAF does not. Nissan exploits this lack of government oversight for pure battery cars to their advantage by excluding a capacity warrantee. Nissan does not have to offer an 8 year duration warrantee, but for marketing against Prius and Volt (that are both required to), Nissan offers it, too. The Nissan warrantee is just worthless, however.

  9. edatoakrun says:

    Anyone interested the usefulness and validity (or lack thereof) of this range test, and Tony Williams’ stated conclusions, should go directly to the Thread at MNL for the discussion on this topic.

    http://www.mynissanleaf.com/viewtopic.php?f=31&t=10040

    1. Marc Lee says:

      Actually there is no test more valid than actually running the car out in the wild. You can put a battery on a test bench, but that tells you nothing about the variables of running it as complete system out on the road.

      1. Marc, don’t worry about Ed up there^^^ He finds fault in just about anything I’ve done, related to the LEAF. I produce a range chart that he finds to be a total mess also. The other thousands of people who use it, however, seem to like it. It is the basis for the Apple App “LEAF Energy”, and an Android app, too.

        Both Gary and Ed have flocked to this like moths to a bright light.

  10. Josh says:

    Thanks for the test Tony. Great work.

    I am in Houston and can notionally confirm similar results to White272. I am showing 10/12 capacity bars and have roughly 80% of the range I had on Day 1.

    I am admittedly tough on the pack; 100% charge every night (needed for the 66 mile commute) and 1 – 2 DC QCs per week. I will hit 25k miles tomorrow in 15 months since my lease started.

    I have the same conclusion as you. I love my LEAF! It is a great car, but the battery cannot handle my climate or commute.

    I contacted Nissan about 3 months ago when my second capacity bar vanished. Still no response from them. For me I think the damage is done, my money will be going Tesla’s way after my lease ends.

  11. Arizona EV Pilot says:

    Tony Williams great job!

    Boo Nissan’s Ghosn, Perry and Palmer for lying to the reporters and frauding the Phoenix owners this whole time. Honesty and immediate action to make these owners whole could still save this program. It is time for Nissan’s board of directors to get involved (emergency session) and hold these individuals(Ghosn, Perry and Palmer) accountable.

    1. vdiv says:

      Boo indeed. I don’t care what Nissan does internally, but for the sake of all EVs they need to make this right. Hopefully they are, but not ready to announce it just yet.

  12. vdiv says:

    This is an exceptional effort. Thanks to all who made it possible and to Tony Williams for putting it together!

    The battery issue is very hard on the Leaf owners and your frustration, disappointment, sense of betrayal, and downright anger is unfortunate and understandable. But from a fellow Volt driver who has not always been happy with my car maker, please, please, please do not give up on EVs altogether!

    1. I don’t know very many folks (beyond those who had poor planning when they bought that first EV) who would want to go back to an oil burner.

      I may get any number of different cars in the future, but I think I bought my last new oil burner.

  13. JPWhite says:

    Very well run range test, thanks to Tony and the ‘donor’ leafers.

    Still got 12 capacity bars here in TN, but got caught short last weekend, the range is poor compared to new.I can’t get the 80 mile range I used to.

    My only hope is that Nissan are eagerly waiting for the second gen battery Goshen has vaguely hinted at and will install these in affected LEAF’s or offer great trades to a 2013. They know who those drivers/cars are thanks to their annual battery check data. It would make little financial sense to replace batteries with the gen 1 battery, the same fate will occur, I understand their wanting to wait, but the silence is doing irreparable harm to their reputation as a credible EV manufacturer.

    Legally they are on firm ground, we all signed acknowledgement that the battery would lose capacity and it isn’t warranted. However the court of public opinion will not favor Nissan if they continue to stonewall without hope for any voluntary recall for what is a clearly an inferior EV powertrain.

    1. Stuart22 says:

      Given their knowledge to date of this issue, Nissan would IMO be negligent not to mention to prospective LEAF buyers of possible heat problems with the battery. Question is – are buyers being informed?

      Perhaps Nissan fears sales will totally tank if they admit to the fact the LEAF battery has a design flaw, and they will be stuck with lemons rotting on dealer lots.

      Not informing LEAF buyers would simply be adding fuel to the fire. The time to cut losses is now, before they grow too large.

      I’ve long criticized Ghosn as being a narcissist, and what’s happening now with his company not taking responsibility for the obvious confirms my feeling. Narcissists will blame others for mistakes of their own creation, and feel little or no compassion for those affected. This whole fiasco more and more appears to be a case study.

      Isn’t there anyone else at that company with the courage to stand up to and push aside this tyrant who is on track to run the whole company into the ground?

  14. Marc Lee says:

    I also want to thank Tony and all of the folks over at MNL who are doing all of us a favor with the great discussion about all things EV and all the info that gets brought to light those discussions.

    I really can’t understand what Nissan is thinking. They have the opportunity to make these people, and their friends, and their relatives, and their children customers for life. All the good will they built up by being first to committ to 100% gas free is now being lost or least seriously diminished for want of an appropriate response to this issue.

    Tony, any theories on how Blue534 at 74% on GIDs produced 94.9% of the projected range of a new vehicle?

    1. No, I don’t. My first thought was somehow that car did not reach 100kmh for some reason (checked with GPS), but beyond that, the faulty instrumentation issue must be worse in this car than others.

      The coulomb counting, which is the basis for our Gid count data, is obvious not very accurate. But, it’s a tough job. I have physically met with the LEAF chief engineer (with 100+ others in San Francisco bay, Dec 3, 2011) and listen to him explain how they produce this data.

      First, is uses a relatively cheap “hall effect” device to make the measurement, and then it waits for the car to be turned off to get an Open Circuit Voltage (OCV) to make adjustments. Of course, we never let that adjustment take place, because the car was driving straight through to “Turtle mode”, so the entire calculation throughout the run was dependent on that hall effect device.

      There is most probably some actual cell degradation in any of the cars. It would not make sense that there would not be in that heat.

      Finally, I think there is a control, software, and/or algorithm issue with the BMS, which should be mostly uniform for all cars. Cell degradation and hall effect variations would most likely have the wider variation that we’re seeing.

      1. Chris Lynt says:

        I would not be surprised if when Nissan finally gets on the ball and solves the problem, that it resides in the charging circuitry. Perhaps that circuitry is not sufficiently heat-resistant? Hall effect sensors are subject to stray field interference – perhaps some manufacture/assembly problem resulted in inadequate shielding from stray magnetics? Heat has a tendency to have adverse effects on things like processors, too. Copper wire resistance goes up with temperature. Suppose due to a heat-induced measurement glitch, the battery packs are routinely over-charged, resulting ultimately in damaged cells and capacity loss? Or perhaps the sensing circuitry has been damaged and misreads battery capacity? If that’s the case, switcching batteries will not solve it. Could be a bad batch of circuits from China? Perhaps Phoenix has brown-outs and the AeroVironment chargers malfunction under these circumstances? (No info on what chargers folks are using, btw.) With so many possibilities, I can understand why Nissan is taking so long to find the answer. I also understand the frustration early-adopters are experiencing. I took delivery of a 2012 Leaf in Dec. 2011, but I reside in Northern Virginia, generally quite a bit cooler than Phoenix. This may take months to sort out, so be patient – easy for me to say, I guess? BTW, I have an MS in Computers and Electrical Engineering and still love my Leaf. Hope the story has a happy ending for all.

        1. Chris Lynt says:

          BTW, when a current flows in a conductor and generates a magnetic field, the Hall-effect device in proximity thereto produces an output voltage proportional to the current in the conductor. The only REAL way to accurately measure the energy that is stored in a battery is to fully charge it and then fully discharge it through a known load resistance while taking measurements of the voltage across the load resistance to derive instantaneous power until fully discharged over time. Determining how much energy remains is without discharging in that manner is problematic. I deduce that in the Leaf, the Hall-effect measurement is being used to calculate an estimate of the energy in the battery by measuring the current with the Hall-effect sensor, and then using a measurement of the battery/load terminal voltage to calculate an instantaneous power, then using the change in power wrt time to estimate the energy left on an energy curve. However, everyone of ordinary skill in the field knows estimating battery capacity in such a manner is not very accurate or satifactory. One battery may differ from another in internal resistance for example and have a difference energy curve and present a different output current profile. Differences in temperature affect resistances in any conductors, so calculations can be skewwed unless temperature is an included variable. Lithium cell discharge voltage curves are not linear, they have a ‘flat’ part, but towards the end fall off steeply between 80% and 100% discharged – 0% and 20% charged. Between 20% and 80% is the flatest part of the voltage curve. It seems to me, in the Leaf, much depends on knowing/estimating accurately the energy stored state of the battery, a very hard thing to know/estimate very precisely. Both charging and operating depend on the accuracy of the estimate, and if temeprature is NOT included in the estimate calculation, error increases. I suspect, therein lies the rub. If so, the solution may be better estimation software, sensors, processing, or all of the above. Not an easy fix, unless it’s aa failed/subpar component or software oversight.

  15. arlene says:

    Very nice testing protocol and writeup. Like Tom, I’ve been in the BMW program and had no experience with Leaf. Engineering-wise, most of the operational characteristics revolve around how the batteries are treated – ambient conditions, SOC, etc. and the actual battery chemistry and associated BMS. With three years of driving, my Mini had no measurable degradation. I live in a very moderate climate, but even so, one would expect measurable changes. The manufacturers play the battery management data very close to their vest. No surprise there, since there is considerable variance. The Mini had Lithium NMC type chemistry, and I’m personally convinced of its superior characteristics, although the titanate variations look promising. Before the Volt came out, the IEEE did a nice writeup on the battery research done inside of GM, and it clearly made the point this was new territory and extraordinary caution was needed. I have been a bit taken aback by Nissan’s (seeming) naivete in what they eventually sold to the public. Maybe the product cycle was so ambitious, this is the fallout. Too bad. Like any other bad publicity, this damages our movement forward into what I personally believe to be inevitable.

  16. SolarExec says:

    This is just total bs from Nissan. I was on the wait list for the leaf and cancelled because Nissan would not warranty the battery (as I posted about 20 months ago on MNL). But I really hoped I would be wrong. The leaf owners here have shown incredible loyalty to Nissan. They have spent time and money trying to help the company improve the car. Nissans reaction is inexcusable.

    I bought 2 Volts instead of a Leaf. I have 26k on mine, live in Houston, and periodically do a very similar battery test to see how it is holding up. Last week I drive my test route (I-45) at 63 mph with AC on Eco mode. The car went 46 miles before the range extender kicked in. That is 2 miles less than I got last year but a small enough difference that I have chalked it up to ambient conditions. And it is still 30% above EPA estimates so I probably cannot complain.

    I say that not to gloat. Far from it. The leaf community is awesome and this test is more proof of that. But Nissan needs to step up on this issue like GM did with the bogus battery fire risk (offering refunds to any who wanted one and doing a free enhancement for everyone). The gilt has proven at least in my experience that in a hit climate with proper thermal management a case battery can work fine without degradation. Nissan needs to get its acts together before they sully the entire EV category.

  17. evnow says:

    As I’ve written on MNL I don’t buy that the tests proved there is no instrumentation failure.

    Mainly because, the range after which Leaf shows turtle (or stops) depends on that same instrumentation.

    Ofcourse, the test also showed that a Leaf with 10 bars and another with 12 could have the same range. In my book, that clearly shows instrumentation problems.

    1. George Betak says:

      The tests have shown that there is an instrumentation error, but they have also demonstrated that battery voltage was very similar in packs that have reached turtle mode. This should be enough indication that the battery was fully discharged. Four of the cars were tested by Nissan in Casa Grande in July. The range test indicated loss of autonomy within a percentage point or two of the battery state of health determined weeks earlier in a bench test. While there is always the possibility that some sensor or software error caused the Leaf to deliver below spec performance, the more likely cause for the reduction of range is battery degradation.

  18. Russ says:

    From my owner’s manual:

    The capacity of the Li-ion battery in your vehicle to hold a charge will, like all such batteries, decrease with time and usage. As the battery ages and capacity decreases, this will result in a decrease from the vehicle’s initial mileage range. This is normal, expected,and not indicative of any defect in your Li-ion battery. NISSAN estimates that battery capacity will be approximately 80% of original capacity after five years, although this is only an estimate, and this percentage may vary (and could be significantly lower) depending on individual vehicle and Li-ion battery usage.

    Use of quick charge should be minimized in order to help prolong Li-ion battery life.

    NISSAN recommends charging the Li-ion battery using the long life mode to help maximize the Li-ion battery useful life.

    To prevent damage to the Li-ion battery do not expose a vehicle to ambient temperatures above 120 degrees F for over 24 hours.

    If the outside temperature is −13 degrees F or less, the Li-ion battery may freeze and it cannot be charged or provide power to run the vehicle. Move the vehicle to a warm location.

    Translation: Expect faster than normal battery degradation if you live where ambient temperatures one foot above a hot asphalt road will consistently exceed 120 degrees and/or you drive 30,000 miles annually.

    1. George Betak says:

      Russ, the owners manual is quite vague in many regards, and especially when it comes climatic conditions, and how they affects the lifecycle of the battery. I remember you stating on Green Car Reports that the battery operated in 70 F temperature for you in Seattle and at 120 F temperature in Phoenix. This not true, and a false assumption. While the battery in every Leaf sits at ambient temps most of the time, we must account for some variation there. Obviously, it’s hotter during the day, and cooler during the night. Then there are seasonal differences. I compiled a table with effective temperatures, and the corresponding aging factor for many locales across the US based on our discussion on MNL. It shows that the batteries age about twice as fast in Phoenix than in the rest of the country, and about three times as fast when compared to Seattle. Please have a look:

      http://bit.ly/QY16IG

    2. Duncan M. says:

      It does seem, from the excerpt from the owners manual, that the battery life is actually within normal parameters. I kinda have to wonder about the mentality of EV car users who buy an EV then expect to be able to drive it to 90+ % of rated range every day and/or use repeated quick charges, but then expect no range degradation in return even though the manufacturer has stated that a 20% drop in capacity over 5 years/60,000 miles was to be expected . It seems to me that at least part of problem is that the owners didn’t do their due diligence when deciding if the Leaf actually had enough range for their commute and/or driving style and then decided to put a figurative gun to Nissan’s head to get them buy back the vehicles. The owners, many of whom have a technical background, should have been able to understand they couldn’t expect new car performance for the entire life of the vehicle.

      1. >>>>> I kinda have to wonder about the mentality of EV car users who buy an EV then expect to be able to drive it to 90+ % of rated range every day and/or use repeated quick charges, <<<<>>>but then expect no range degradation in return even though the manufacturer has stated that a 20% drop in capacity over 5 years/60,000 miles was to be expected <<<<>>>The owners, many of whom have a technical background, should have been able to understand they couldn’t expect new car performance… <<<<

        And what of owners that aren't technically oriented? What should they expect? 100 miles that Nissan advertised? 80% in 5 years (of which dozens and dozens are reaching in about one year in Phoenix)? The 73 EPA miles?

        How about a 12,000 miles per year driver in Phoenix that will have 38.4% loss (61.6% remaining) in 5 real earth years (from Nissan's newly released "secret" data)?

        How about battery "End Of Life" (considered industry wide at 70%) of less than 4 years / 48,000 miles? (Nissan data for Phoenix).

        Or, the 73 mile EPA range LEAF in Phoenix that now has 45 miles of total range in 5 years with that 12,000 mile/year average driver, or only 33 miles until the Low Battery Warning comes on? (again, Nissan data, not mine).

        Clearly, nobody asked for, or expects new car performance forever. Unfortunately, in hot places like Phoenix, Hong Kong, Spain, Texas, and Southern California, these cars aren't keeping that new car performance very long. They are losing battery capacity, more every day.

        In the case of my car, "Black782" in the test, not even 5 months passed from the manufacturer's date before I lost 10% capacity.

        Tony

        1. Duncan M. says:

          “in the case of my car, “Black782″ in the test, not even 5 months passed from the manufacturer’s date before I lost 10% capacity.”

          Measured How? Did you run the car/cars on a cycle that duplicated and/or approximated the EPA test cycle? It appears that you ran them at a steady highway speed which is not the same as the EPA highway test:
          http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

          According to the EPA highway tests, a new Leaf should use 34kw to go 100 miles, so with a 24kw battery, this would indicate a highway range of 70.5 miles using their cycle with an average speed of 48.3 mph.

          1. Duncan, we were not trying to duplicate EPA data in any way. I only mention it as a published official range from the US government’s own tests.

            My own car, “Black782″, has in fact gone over the 84 mile range at 4.0 miles per kWh that Nissan publishes, and it met or exceeded that threshold numerous times over the 1800 mile course of the Baja California (Mexico) to British Columbia (Canada) trip that I took, June 12-20, 2012. “Black782″ was manufactured April 2012, and sold new with 5 miles on the odometer May 2012. It was leased specifically for that trip, and replaced my previous LEAF, “Red244″, that had experienced about 15% loss of range in the 25,000 miles / 1 year it was driven.

            Red244 was used to develop a range chart that I produce, which specifically has a column for 3.9 miles per kWh to equal 82 miles (21kWh useable new battery capacity at 70F/20C). Therefore, that same new battery equals 21kWh * 4mileskWh = 84 miles. This also matches Nissan’s technical service bulletin data mentioned in my paper. Yes, like Red244 before it, Black782 did in fact go 84 miles in those conditions.

            In addition, some crafty folks over at the “MyNissanLEAF” forum found a driver who carefully documented his drive this past April. He drove at 65mph indicated (1mph faster than our test) in slightly more dense air (94% versus our test at 92% air density) at almost exactly the same temperature of 80F, with nil wind, on very level Dallas freeways, and recorded 83 miles to the “Very Low Battery” warning. There is approximately 8.6% battery (about 1.8kWh) remaining at this point, and I estimate that he could have added 6 more miles until turtle mode for 89 total miles.

            So, the point is that the car can, and does travel 84 miles (or greater) with a new battery with those parameters.

            So, how do I know my car lost about 10% range? As I stated in the paper, Black782 only measured about 89% stored energy on the day of the test. It drove 76.6 miles, or about 91% of the 84 miles it was capable of driving and actually demonstrated when new. The fact that the measured stored energy and the demonstrated test range are within about 2% gives a strong correlation that the car is in fact 10% reduced in range.

            1. Duncan M, says:

              You’ve basically created your own vehicle performance metrics rather than using Nissan’s or the EPA’s. The fact that the car, could, apparently, exceed it’s stated range when new is not the same as stating that it has lost capacity when, after a year, it still meets it’s stated EPA range rather than exceeding it. A ~10% decline in the first year and gradual decline after that is within the stated battery pack performance envelope, and the manufacturer seems to have reduced it’s advertised range to take this into account. Nissan never guaranteed the performance you obtained when the car was new.

              1. Duncan, now you’re hindering your own argument. Losing range means just that. Don’t over think this. You state correctly that we used our performance metrics, and then try and compare that to a completely different metric (EPA data).

                Our metric, again, is indeed our own testing, tested many, many times in addition to this test. Our test’s specific performance is backed up with Nissan’s technical data. Not Nissan’s marketing data (100 miles) or EPA (73 miles).

                You seemed to be confused on a few things. First, firmly grasp that Black782 went about 10% less range autonomy on Sept 15, 2012 than it did with similar metrics in June 2012. That’s just a fact.

                Nowhere did I state, on insinuate, that was above or below any Nissan claimed normal or abnormal parameters. In fact, we intended this car to be one of two “control” cars for the test. So, we weren’t looking to “prove” it had reduced range. QUITE THE OPPOSITE!!! We intended that it would, in fact, drive the 84 miles we specified, per Nissan’s technical data.

                I hope I’m making this clear,

                Tony

              2. Oh, forgot to add, you are absolutely correct. Nissan does not guarantee any range ever, but they also don’t specify range in their warranty exclusions. That will get them in a bit of trouble in the upcoming lawsuits, since battery capacity is what the specifically exclude.

                To a consumer, range is the problem they are having. It’s a battery capacity issue for only Nissan.

        2. Mark H says:

          There are two issues that people are watching. The first is for Leaf owners and determining the battery degradation of the Leaf. The second is battery degradation of EV batteries in general. I am curious with so much detailed data if your group has gathered any data on other EVs for a point of comparison? Of the 20 odd EVs entering the market, the Leaf and Volt are the first out of the gate. The Volt actually carries the warranty many Leaf owners thought that they had. I have heard the statement that the government required such a warranty out of the Volt, but it appears that the Volt and other EVs with a liquid cooled battery system does not suffer these problems. I point this out not to pile on the Leaf, but to help new comers to the industry reading these feeds. The Leaf is an excellent EV. The battery technology for the industry is growing rapidly and most likely will not require a liquid cooled approach in the very near future. There is a lot of great data here. I am optimistic that Nissan will resolve this in the months to come.

          1. The third big thing they are watching is how Nissan handles this. We are currently waiting for a video interview with Andy Palmer to be released any day concerning these issues.

            It was to have already been released, but was held up because it was determined to be “corporate spin”.

            Tony

            1. Mark H says:

              Fare enough. We all want to aid in persuading Nissan to do the right thing, but at the same time make sure the industry is aware that there are current options available today that are viable. I think GM did a very smart thing not only with the liquid cooled but sizing/mileage of their battery as well. Just as one must deal with the degradation of a solar panel in sizing a PV system, 16kwh battery leaves a bit on the table to achieve only 38miles. The chemistry remains the same but that means nothing to the non technical buyer as you stated somewhere earlier. I personally applaud your efforts. I think you are spot on in your delivery.

  19. TropicalLEAF says:

    Hi Tony,

    Thank you for carrying out the experiment. I appreciate the thoroughness.

    What is the ideal temperature range for the battery?
    Is there a temperature vs rate-of-capacity-loss chart somewhere?
    Has Nissan ever published these?

    I have a 3-month old LEAF, here in sunny Singapore, where night time temperatures rarely ever go lower than 24 deg C (75 F). Daytime temperatures are usually between 30 and 34 deg C. (86 to 93 F)
    Of course, under direct sun-shine, I’m sure the the temperatures around the battery pack could exceed 50 deg C (122 F).

    1. Ideal temperature for the battery must be defined. Ideal long life is at a very cool temperature, and maximum range is at a very warm temperature. Obviously, the two extremes are not complimentary. 70F is a good compromise to long life and long range.

      Nissan has never published a heat – degradation table, but we have learned about how Nissan is able to claim that all the Phoenix cars are “normal”, regardless of measured battery performance or range.

      Nissan has recently announced what heretofore has been a state secret; a “Nissan-LEAF-Year”(TM) of battery degradation is 7500 miles in Phoenix. Sure, they never bothered to tell a single leasee (or owner) while they signed up for a normal lease of 12,000 miles per year. It’s not in advertising, pages of liability disclaimers, or statements from Nissan on degradation.

      So, in 5 real earth years, that normal 12,000 per year driver will drive 60,000 miles, or the equivalent of 8 of the Nissan-LEAF-Years(TM) of 7500 miles each.

      With reindexed data in the past few days of 76% battery capacity remaining (from the previous often quoted 80%) in 5 Nissan-LEAF-Years(TM), the average annual degradation is about 4.8% per year. Therefore, a 12,000 real world miles per year driver will have 4.8% of degradation multiplied by 8 NLY’s, or 38.4% loss (61.6% remaining).

      The 73 mile EPA range LEAF is now 45 miles of total range in 5 years with an average driver, or only 33 miles until the Low Battery Warning comes on.

      1. TropicalLEAF says:

        Thank you for the info.
        Really disappointing that Nissan isn’t being more transparent.

  20. Mike H. says:

    I develop battery chargers and battery managers for Li-ion and VRLA chemistry batteries. I’d like to thank the author for his good work in experiment definition, recording, and presentation. I hope the author is not put off by critics. The Leaf is a product containing a battery; not a battery. The experiment measures the product performance, which is what we all experience when we buy and use such a product. Independent testing of the battery itself isn’t useful unless users can modify or develop their own battery management systems and that isn’t going to happen; is it?

    I am not surprised by the abrupt drop in capacity early in the product life. All Li-ion cells show a substantial (10-20%) capacity drop within a few dozen cycles, then provide a shallow slope of capacity loss for most of their remaining charge cycle life (say, 80%), then drop again quickly near the end of their lives. Envia Systems; a promising Li-ion IP developer, shows a capacity vs. cycle graph which, while demonstrating great specific energy and energy density, shows the same ‘shape’ as every other Li-ion capacity/cycle life graph I’ve ever seen.

    1. Thank you for your sage words and compliements. There is a core group of deniers / haters that hit all the various internet sites, but the good news is that it’s generally the same tiny group of individuals.

      The sooner that we can get past this issue, the sooner we can continue to grow EV’s in the world. The battery will not change for 2013, as I reported skepticism in my paper about Carlos Ghosn’s Wall Street Journal comments. We have learned this recently from the Nissan engineers in Smyrna, Tennessee.

      So, with the same battery, we need a forthright presentation to new buyers about what the car can do, so that we eliminate these blow ups in the future. Sure, many would not buy the LEAF who might have otherwise bought if they thought it went 100 miles, or that it would go the EPA 73 miles in 5 years. But, those who do buy will have have a firm understanding of what to expect, and that will mitigate blow ups.

      The car can only grow to a global super power on par with Prius with honest data.

      Tony

  21. Yakob C. says:

    Tony,

    This might be already specified in your test, but I missed. I assume the testing was done at Normal mode and not the Economy mode?

    I have a Leaf with only 3000 miles (2012), I have noticed an abrupt a significant loss of capacity recently. While it will show the correct number of segments after a full charge (either 100% or the recommended 80%), the remaining miles and the number of segments come down at a faster pace after about 10 miles or so. I always have been driving the car in Eco mode, I used to get 95+ miles, but now it is about 75 or lower I think.

  22. Actually, the test was run in ECO mode, but not for any real performance purpose; they reason was purely for “show”.

    ECO mode does three things:

    1) Increases regeneration. We didn’t have regeneration at 100kmh on flat highways.

    2) Decreased heater / air conditioner output. We didn’t have any, since it was turned off.

    3) Reduces sensitivity of “gas” pedal. Not a factor in our test, as the car was run on cruise control.

    The reason we did it is because it left a simple “loophole” for the PR folks to simply say that the car could have gone XX miles further in ECO mode, so that’s what we ran. The reality is that our test cars would drive EXACTLY the same distance in either mode.

    As far an an experiment, either mode could be used interchangeably.

    Tony

  23. >>>> I always have been driving the car in Eco mode, I used to get 95+ miles, but now it is about 75 or lower I think. <<<<

    What you are referring to is the "Distance To Empty" gauge, or what I referred to in the paper as the "Guess-O-meter". Sadly, it's not a very good reference for determining absolute range, however many people find it useful in very level area with consistent driving techniques. If you are in Florida, Kansas, or similar flat areas, that is where it works best.

    I personally don't use it at all. I produce a "range chart" used in conjunction with the aftermarket "Gidmeter" to determine range.

    Tony

    1. Yacob C. says:

      Tony,

      I know it is not ‘that reliable’, but I have kept track of how consistent it has been in the last 3000 miles, and it has been fairly reliable for me. [I am an electrical engineer]. The guessOmeter and the number of segments left were coming down together well matched. After this changed in my ‘observed’ capacity, I had also ran the car pretty low in battery, but not low enough to reach the ‘battery low’ warning condition. Always the reading comes drastically (much more quicker than it used to be) during the first miles or so.

      In your test, was the number of segments ‘pretty much’ track the Gid meter readings also? It as not clear from your table of results.

      I am surprised to hear (I am assuming this from the various posts here), that Leaf does not have a voltage reading per ‘replacable module’ built into the battery system, which can be monitored at least by their service dept, so that when a module under-performs or fails they can replace it easily. The only way to know if the individual replaceable module performance without disconnecting the module, is to measure the voltage under load condition, after some discharge. So how do they find out which module might have failed now?

      Ideally, that voltage readings should be available on one of the readable interfaces (such as the CAN bus) , and when there are voltage differences between the modules, they should be saved for the service people to look at later

      1. We didn’t track the “fuel bar” segments, as they aren’t particularly useful for our test. The only “hard” data points are the Low Battery Warning at 14.7% and Very Low Battery warning at 8.6%. They are consistent even with degraded batteries so that a 50% degraded battery would still show 12 fuel bars when fully charged, however LBW would pop up with numerous fuel bars still showing. Check out the range chart we developed:

        http://www.mynissanleaf.com/viewtopic.php?p=101293#p101293

        Nissan has a test suite, “Consult III”, to identify bad cell pairs and modules. We did monitor the pack voltages on every car, as stated in the paper. A future consumer device, “LEAFscan” will give us many of the capabilities of Consult III.

  24. Yakob C. says:

    Tony,

    After re-reading your test results, I think the guessOmeter you refer to is the ‘mileage left in the battery’ indicator display? But not the number of segments, right? In your test, the remaining capacity by Gids and by the segments vary only by about 3% or so worst case. What I am experiencing is more than 20% drop with respect to what I used to have.

    What do you suggest is a more controlled test to estimate the current battery capacity without a Gids meter? Running it all the way down until ‘the low battery’ indicator comes on? I wish you had driven all the cars, after the current set of measurements was completed, all the way until the battery LOW came on. That might have been more ‘forceful’ message to Nissan, since they do not recommend one drive the car after reaching that stage.

    1. Yes, GOM equals “Distance to Empty”; the numerical display of range on the dash. There isn’t a direct correlation to fuel bars displayed.

      You have to be careful mentioning “segments”, because there are fuel bar segments and battery capacity bar segments. The Gids and capacity segments were close, but significantly off from actual store energy.

      You can get quite good range data by just driving the car to LBW or VLB. We didn’t need a Gidmeter to conduct this test; it was a convenience to estimate range (and calculate the turn around point on our course) and for the operator to estimate when they would hit turtle (and need a tow).

      1. Yakob C. says:

        Tony: “Yes, GOM equals “Distance to Empty”; the numerical display of range on the dash. There isn’t a direct correlation to fuel bars displayed.

        You have to be careful mentioning “segments”, because there are fuel bar segments and battery capacity bar segments. The Gids and capacity segments were close, but significantly off from actual store energy.”

        Tony, in the last sentence above does ‘actual store energy’ mean fuel bar segments?

        During your controlled test ‘the battery capacity bar segments’ would not have changed, since they change over longer periods only, right? You just recorded it once (unless it changed at the end of the test, very unlikely) So your testers recorded the Gids data and ‘the fuel bar segments’ during the tests? Is my understanding of the above correct? If not, then your test ending for each car must have been till battery exhaustion by LBW or VLB. Could you please clarity, for somebody just jumping in…

        IMO, the ‘fuel bar segments’ data is based on the voltage of the battery (with some time-averaging, perhaps). While the battery voltage could vary wildly for short periods when load on the battery changes (which does vary significantly in normal driving: acceleration vs regeneration), under a similar reasonably normal load, when discharging, the voltage has a real good correlation to the stored capacity for all LiIo batteries.

        1. “Tony, in the last sentence above does ‘actual store energy’ mean fuel bar segments?”

          No, it does not. If the battery were 50% reduced in capacity, those fuel bars would also be each 50% reduced in capacity. They do not have a uniform amount of energy.

          LEAF battery capacities

          New 70F/20C fully charged battery
          12 Fuel bars segments showing, each bar with about 1.5kWh – 1.8kWh:

          ——————-KWH——-Gid——SOC%
          Rated capacity: –24 ——- 300 —- 100
          Max possible. : —24 —— 150 —– 100
          Stored energy: –22.5 —– 281 —– 94
          Usable energy: –21.0 —– 281 —– 94
          Depleted cutoff: –0.5 —— 5 ——– 2 (zero fuel bars remaining)

          70F/20C fully charged, 50% dedraded battery
          12 Fuel bars showing, each bar with about 0.75kWh – 0.9kWh:

          ——————-KWH——-Gid——SOC%
          Rated capacity: –24 ——- 300 —- (not possible)
          Max possible. : — 12 —— 150 —– 100%
          Stored energy: –11.2 —– 140 —– 94
          Usable energy: –10.5 —– 140 —– 94
          Depleted cutoff: –0.5 —— 5 ——– 2 (no fuel bars remaining)

          “During your controlled test ‘the battery capacity bar segments’ would not have changed, since they change over longer periods only, right? ”

          None did change, but as noted in the paper, on car did the very next day, from 12 to 11. It had previously been at 10, and then “reset” by Nissan with a software upgrade.

          “If not, then your test ending for each car must have been till battery exhaustion by LBW or VLB. Could you please clarity, for somebody just jumping in…”

          10 of the 12 cars were run to “turtle mode”, and some to battery cut-off. The difference is less than 1/2 mile at 100kmh. Two of the cars were only run to Very Low Battery, as we had (at that point) 4 damaged cars from towing. I elected to have those two cars drive in, instead of being towed.

          “IMO, the ‘fuel bar segments’ data is based on the voltage of the battery (with some time-averaging, perhaps). While the battery voltage could vary wildly for short periods when load on the battery changes (which does vary significantly in normal driving: acceleration vs regeneration), under a similar reasonably normal load, when discharging, the voltage has a real good correlation to the stored capacity for all LiIo batteries.”

          Corrections to cacpacity are only made during “Open Circuit Voltage” periods. We didn’t have any during the test. The pack voltage does not “vary wildly” ever. Starting cell/pack voltages in ever case were 4.1/393.5, plus or minus a VERY small tolerance.

          Those voltages are a poor measure of capacity.

          1. I made at least one error in the above post:

            ——————-KWH——-Gid——SOC%
            Rated capacity: –24 ——- 300 —- 100
            Max possible. : —24 —— 150 —– 100

            That 150 Gid in the first table should read “300″. I used cut and paste !!!

  25. Yakob C. says:

    Tony,

    Is it possible to collect the following data from the great volunteer team?

    How many times had they charged (estimate) on a fast charger?

    And include that data in your results please!

    BTW, is there a class action law suit against Nissan on this issue?

    1. I don’t think many used DC chargers that much, because there just isn’t that many in Phoenix (3 or 4 in the whole region).

      Yes, there is one poorly written (both from a technical and legal perspective) class action, and several others that will be much more polished (and more likely to be successful).

  26. Yakob C. says:

    Tony,

    Thanks for the clarification about the ‘remaining charge’ value of each bar being approx. 1/12 of the max. capacity of the battery now. So I assume, even the capacity bars go down from 12 to say 10, after a full charge the remaining capacity bars will show 12 ? OK.

    In my case after 4 months (less than 3000 miles), my capacity bars (the shorter ones on the right) is still 12. But the other bars are going down considerably faster than in the first 3 months. I have not reached a battery low warning test yet, a little more to go (usually I have been charging when it reaches about 30 miles to go, and most of the times charging to 80%). I have been getting about 95 to 100 per charge in my normal careful driving in econ mode most all the times before. I have a feeling this one will get me only about 70 or less. Will see in a couple of days.

  27. George B says:

    Yakob, sorry to hear about diminished performance of your Leaf. Would you mind telling us what your approximate geographic location might be? Also, did you share your observations with your dealer and Nissan’s EV support line?

  28. Padraic says:

    Hi, did you use anything besides the instrumentation to measure the battery capacity?

    1. We recorded pack voltages, SOC %, Gid number and %, capacity bar segments and fuel bar segments (dash instruments). Also recorded was cell voltages (all well within 50 millivolt). All these are taken from the respective data busses using our own equipment, however all sensors are from the vehicles equipment. No external (laboratory grade) measurements were made of the batteries.

      However, two of the cars that we have data from were laboratory load tested at Nissan’s Casa Grande test facility in July / August. Those two cars were within about 2% of the lab test % to our road test performance.

  29. We drove a brand new LEAF (RedXXX) on Nov 4, 2012 in Phoenix with only 138 miles on the odometer (and a recent production date) to run the exact course and parameters in similar weather as the Sept 15, 2012 LEAF range autonomy demonstration. This was a shortcoming of our original test, with no “control” car that was capable of producing 84 miles of range autonomy at 4 miles/kWh.

    83.2 miles driven (with 21 Gids / 7.47% remaining)
    88.7 miles calculated range to turtle

    Start time: 12:58 pm, November 4, 2012
    Start battery stored energy: 265 Gids / 94.3%
    Start pack volts: 393.5 (4.1 per cell average)
    Start SOC: 91.4%
    Start GOM: 103
    Start temperature: 6 bar segments
    Economy: 0 miles/kWh (reset)

    End of test battery stored energy: 21 Gids / 7.47%
    End time: 2:21 pm

    TEST COMPLETE. The car was driven an additional 4 miles to a charger when these readings were recorded:

    Gids: 11 / 3.9% remaining
    Pack volts: 317.5 (3.3 volt average per cell)
    SOC: 4.3%
    GOM: “—” (normal for “Very Low Battery”)
    Battery temperature: 7 bar segments
    Economy: 4.3 miles/kWh

    [u]Time (MST) – Temp – Dew Point- Hum- Press – Visibility – Wind – Wind/Gust — Precip — Conditions[/u]
    12:51 PM 84.0 °F 30.9 °F 15% 30.00 in 10.0 mi WNW 3.5 mph - N/A Partly Cloudy
    1:51 PM 88.0 °F 30.0 °F 12% 29.97 in 10.0 mi Calm Calm - N/A Partly Cloudy
    2:51 PM 89.1 °F 28.9 °F 12% 29.96 in 10.0 mi Calm Calm - N/A Partly Cloudy

    1. Jay Cole says:

      Thanks for that date point Tony. That was a biggie.

      /good stuff