Nissan LEAF Gets Replacement Battery After Mysterious 4-Bar Loss In 4 Months


Jennifer Bradbury posted this on the ‎Seattle Nissan LEAF Owners Facebook group:

“Seriously! ANOTHER one bites the dust!!! Bought used in July with 12 bars… I have now lost 3 bars in about 4 months!!!!! Starting to get upset…. I knew 1 was going soon… Sad that a second went but okay.. A third. In such a short time.. That’s ridiculous! At this rate I’ll have no bars in a year!”

Along with this image showing 9 capacity bars remaining on her newly purchased Nissan LEAF:

Nissan LEAF With 9 Bars...Soon To Be 8.

Nissan LEAF With 9 Bars…Soon To Be 8.

That Facebook post now has 193 comments and counting, including several from Seattle LEAF owner David Laur.

Laur took it upon himself to hunt down information on this particular LEAF (based on a VIN search of #222, the LEAF purchased as certified used by Jennifer) and his findings (via My Nissan LEAF) were shocking.


LEAF VIN #222 Now Owned By Jennifer Bradbury – Image Via David Laur

So, this particular LEAF was down 3 bars back on November 19, 2013, but when Jennifer purchased it in July of 2014, the same LEAF magically had all 12 battery capacity bars.

We’re not going to place blame on any party here, as nobody seems to know exactly who tampered with the LEAF’s lithium-ion battery controller (LBC), but it’s evident that some foul play was in place.  From a Nissan dealer tech who shall remain nameless:

“If you PM me your vin number I can run it thru DCS (Nissan Warranty Tracking program) You might have some legs to stand on. In order for a LEAF to be sold as a certified car it has to have 11 bars at minimum. A dealer with a somewhat knowledgeable tech would be the only one’s that could reset a degradation meter like that. All the battery info is stored within the battery controller and it uses long term readings to decide what is illuminated on the dash. Something funny is going on.”

That tech did indeed stick to his word, discovering something funky went down:

“The certified safety inspection should of shown the LBC had been reset by not allowing a battery report to be printed.”

Why would the LEAF need a certified safety inspection? was sold as a certified used car, which guidelines set forth by Nissan state that the LEAF must be inspected and that a minimum of 11 battery capacity bars must be present or the vehicle can’t be sold as certified used.

LEAF With VIN #222 - Image via Jennifer Bradbury

LEAF With VIN #222 – Image via Jennifer Bradbury

Have we confused you yet?  If so, here’s a overview of the situation:

A certified used Nissan LEAF was purchased by Jennifer with 12 battery capacity bars displayed.  The LEAF then lost 3 bars rapidly (4 months).  A Nissan service tech investigated the background of this particular LEAF and discovered evidence of tampering with the lithium-ion battery controller, but couldn’t figure out with whom the tampering occurred, so proving guilt would be near impossible.

Okay…let’s move on

Current LEAF owner Jennifer was deciding on whether or not to seek out legal assistance, but as she was in the process of contemplating contacting a lawyer, the unnamed Nissan service tech advised her to bring the LEAF in for a diagnostic check.  During that check, the LEAF lost its fourth bar and we all know what that means…

Replacement Time

Back to David Laur.  It was Laur who first published these accounts (here) and it was he who broke the news of Jennifer’s LEAF losing its fourth bar and being eligible for battery replacement (here).  Here’s a snippet from Laur’s most recent article on the now-famous VIN #222 LEAF:

A while back I wrote about a neighbor, Jennifer who purchased a used LEAF last Summer. It has 12 capacity bars and was a good deal. Not a great deal, mind you. Just a good deal. She soon lost her first bar which we told her was likely to happen in the first year. Now keeping in mind the first bar represents a capacity nearly three times larger than the next several bars, it would not be extremely unusual for only a short period of time to pass before losing bar #2.

But the Pacific Northwest’s weather is nearly tailor-made for battery health. Our climate is tempered by Puget Sound so its rarely very cold or very hot. My first LEAF, VIN 258 built nearly the same time but having the advantage of living in the Pacific Northwest went 44,958 miles with all 12 capacity bars intact. At 57.11 ahr, it probably would have lasted all Winter before losing its first bar in mid Spring. So it had at least a few thousand miles to go.

But Jennifer’s bars continued to disappear at the rate of nearly one per month! Something was not right. Further digging found that this EXACT same car was reported as a 3 bar loser by its original owner in Southern CA back in November of 2013.

Obviously, someone was trying to pull a fast one here. She posted her dilemma on Facebook and we encouraged her to get the car inspected and research its history. When the history of the car was reviewed it was immediately obvious that all was not as it was represented to be.

She was able to get it tested and guess what?? During the test, she LOST ANOTHER BAR!!

Jennifer’s replacement battery is reportedly being shipped in from Tennessee and won’t be the so-called “lizard” pack (no…we don’t know why she isn’t getting the more durable pack).  The battery’s install date is a few weeks off (due to some fitment brackets on backorder), so until then she’ll be driving a loaner LEAF from Nissan of Eastside in Bellevue, Washington.

Giving credit where it’s due, Laur concludes:

“Kudos to Nissan Motor Corporation for having the insight to create the paper trail that allows us to know the true nature of the battery’s health. It was the warranty history on the car that provided the proof to warrant the test needed to complete the escalation process.”

*For those interested in more background on this particular Nissan LEAF, VIN #222 was delivered to Los Angeles, California resident Omkar on January 1, 2011.  Here are two links that provide more detail on LEAF #222:

Driving Electric Blog – Omkar visits friend’s house in Nissan LEAF

My Nissan LEAF – VIN #222 Delivery Day

Omkar Plugs In LEAF #222

Omkar Plugs In LEAF #222

Source: Dave In OlyWA

Categories: Nissan

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73 Comments on "Nissan LEAF Gets Replacement Battery After Mysterious 4-Bar Loss In 4 Months"

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Ehh – I’d NEVER trust a “certified” used car. I bought a Prius years ago that was under one of those certified programs. I knew right up front that it would never have passed the certification process for several reasons. I still bought it because the price was right. But yeah, car dealers pass off cars all of the time as certified when they really don’t qualify. So no surprises here at all.


To be fair this is the first such documented occurrence, out of hundreds and possibly thousands of certified used Leafs sold. Since tampering with the LBC is arguably criminal, it’s hard to believe the Tacoma Nissan (where Jennifer got the car) did it, more likely some in-between person, or at the very most a rogue individual working at Nissan.

That said, they clearly didn’t do enough due diligence – if a handful of Leafers on the FB page could figure out the car’s history, so could the dealership.

First documented case, maybe. But I’ll bet you there have been plenty of cases that went undocumented. Not everyone even knows what those bars mean on their dash. Even if they do, lots of people don’t go to online forums. My point is, this sort of thing happens ALL of the time on gasoline cars. But 99% of the time it goes unnoticed and the dealerships get away with it. The customers just aren’t educated enough about cars to spot it. And most of the time it isn’t a big deal anyway. For example the Prius I bought wouldn’t have passed because of previous impact damage. I was able to locate most of the damage because I knew what to look for. But even though it wouldn’t have technically passed as a “certified toyota used car” I could also tell that the damage was repaired properly and thus I didn’t care. And sure enough, the car served me fine for many years. However, dealers play all sorts of tricks to sell used cars. If the check-engine light is on, they’ll just unplug the battery so it will reset the light for a few days – long enough to sell the… Read more »

When you sue, you have to prove damages. Proving a specific party committed a fraud against you (difficult in this case) is only half the suit. The other half is proving that you are out of pocket because of the fraud.

With loaner cars and a new battery being installed, it becomes hard to prove damages that can be compensated by a court.

What she should do is wait until the new battery is installed, and she’s had a chance to drive it around and make sure the new battery solved 100% of the problems. Then if everything is working, file a complaint with whatever regulatory agency licenses dealerships in her state (if any).

Ooops!! this was supposed to be a response to Mike. My bad!

The “out of pocket” is the cost of a new battery because if everything goes against her, she will have to buy a new one with her own money.

This is what gives car dealers a bad name.
With this battery conditions, Jenn clearly paid Too Much for the Car, and should SUE.

Litigation is the last course of action rather than the first.

Jennifer wrote to a Seattle Leaf FB forum, and within the day a Nissan tech who participates in the forum offered her a positive way out. Bottom line, she’s driving a better loaner than her 2011 right now, and will get a free new battery.

Whether the deal includes a non-litigation commitment I do not know at present.

Since the replacement is at a different dealership from the one that was negligent in both the sale and the initial treatment of her problem, suing the individual dealership might be justified. However, the deal might be a blanket one that protects all Nissan entities. In any case, barring new information Nissan corporate cannot be seen as culpable here.

Even though 12 bars were indicated, the car had a limited range from the day she bought it. A simple test would have borne this out — drive until the “Very Low Battery Warning” comes on, then plug it in and see how long it takes to charge. Obviously it is unreasonable to expect a new EV owner to know to try this. It would be great if we could put together a network of LEAF owners who understand how all this works to help prospective buyers of used LEAFs assess battery health. There are also ways to read battery health information directly out of the car, bypassing the dash display, but directly testing charge capacity by timing a charge at a well-known charge rate seems most fool-proof.

Haha, that’s exactly that the Seattle FB Leaf forum is, and quite possibly other similar forums.

There’s also, even though in my experience the discourse there tends to be less friendly and more disparaging towards newbies and non-hobbyists.

Simply put, on FB there participation is not anonymous, and more mixed-gender. This tends to keep the boys closer to their best behavior 🙂

For knowledgeable and friendly (in general) LEAF owners, I must plug the SF Bay LEAFs Facebook. There are a lot of early adopters mixed in with “normal” LEAF drivers (less hobbyist, more pragmatic).

Yes, Jeff, absolutely. The SF BayLEAFs were instrumental in developing LeafSpy and popularizing it within the LEAF community.

This tool is very useful, and has given owners an additional insight into the LEAF and its subsystems, which includes the battery. Obviously, this project was based on prior work, and Jim Pollock, the developer behind LeafSpy, has leveraged the community to a great degree.

The Seattle Facebook community is quite active and has excellent energy. That’s how Jennifer was able to draw attention to her plight, and the LEAF VIN #222 she just acquired after it provided its original owner, Omkar in La Cañada, CA, three years of faithful service.

Jenn probably should sue, but the reality is she’s getting a brand new battery, so she’s actually getting a better deal than most purchasers of 2011 LEAFs. I guess the moral of the story is, buy a used LEAF with excellent capacity retention, or one with really bad retention. But not one somewhere in the middle, where the warranty won’t kick in!

Your “moral of the story ” made me smile! So true! I was incredibly fortunate to have some truly special people on my side. When I made my original post I was just venting as buyers remorse was kicking in and never imagined I’d be getting a new battery for my car. Amazingly I will be better off. Had Nissan refused to replace my battery at 9 bars I probably would have looked into legal action, however as luck had it dropping that 9th bar worked out To my advantage in the approval process. It’s possible the dealership I purchased the car from was unaware the capacity bars had been reset, however I had communication issues with them after they lost my cars sd card and they wanted to charge a 110 diagnostic fee when I called the service dept and expressed concern over my rapid battery loss . I didn’t have the warm and fuzzier with them and I honestly don’t feel I’d be having the same results if I had taken the car back to them. That being said when I get my car back I will be going there. If they we’re truly unaware, they need to… Read more »

I’m very happy to hear you are being taken care of. This is not the kind of thing we need while we’re trying to push EV adoption. A big thanks to Dave for his help here. He’s a good guy. 🙂

Jenn, sorry to hear about the trouble with your LEAF. Great to see that Nissan of the Eastside and the LEAF community have come through for you! Also kudos to Nissan for providing the retroactive capacity warranty for 2011 LEAFs.


Congrats on the good news in this saga!

Who knows? Maybe in ~15 years’ time this Leaf will be a precious collectors’ item. It’s now got both the VIN (000222) and the riveting story to go along with it 🙂

Ooo, and 1st Leaf in Orange County, delivered New Years’ Day 2011.

Oh, this one’s a keeper if it behaves nice from now on Jenn!

I agree ! I am looking foward to getting my car back, I love the car , through all this I am glad I got to did find it’s history as it’s very interesting and is getting “more” interesting, I love that it’s 222 🙂 I am very hopeful that it will fair much better in The northwests cooler climate and last me many years 😉 I have never picked out my own new car before ( I know it’s used but “new to me”. And so the experience was getting me down, in the end I am coming out on top thanks to the Seattle leaf FB group being very supportive. I am especially pleased with Eastside Nissan as they saw something was up and were willing to look even though I didn’t buy the car from them… I just can’t say enough good things about them.

It’s really sad to see this kind of thing happen.

It’s why I won’t buy a used electric vehicle (other than a Volt) until affordable replacement batteries are widely available.

I don’t think Nissan was nearly conservative enough with the way the battery is treated, both in depth of discharge, or temperature control.

I can’t afford a Tesla, even used…

The Volt is the only other that inspires full confidence in the way the battery is used.

I can’t afford a Tesla, and I’m not sure about any other makers, so I’m not buying any used EVs until replacements are common.

I’m currently OK with leasing a new EV, though.

The fade is due to not controlling the temperature. Since I think all EVs other than the Leaf have a thermal management system which will control the temperature, the dramatic battery fade you’re seeing is more a Leaf problem than an EV problem.

The Volt will probably show the least fade, it reserves a big chunk of the SOC, but I don’t think fade will be a big issue in the vast majority of EVs.

Leasing an EV is a no brainer if the mileage works for you.

So you won’t be locked into a “new” technology until it gets better.

I imagine Nissan would address it better as well. You can already see it in the LEAF based NV200 electric van where they at least added a fan to the cooling of the battery (similarly to Prius).

The main reason leasing isn’t quite a no brain decision for me is that I tend to keep my vehicles for about ten years, on average, and really enjoy six of those years without a car payment.

A lease takes that away. I won’t give that up without careful calculation. 🙂

If you down payment and lease payment end up cost you less than 1% of the vehicle then leasing is a good deal. So, effectively you can get 100 month of ownership of new cars every 3 years for about the same value of buying a new car.

That is assuming that your mileage limit works for you.

You need to stop all this complicated crap around the simple process of replacing a worn battery. Hear me, you are losing sales with all this nonsense and you need to clean up your act. If your goal is to control the maintenance activity of the cars you sell, you better start by making the dealers responsible for their actions.

Who was the dealer who sold this fraudulent certified used Leaf? Did I miss this?

They might lose “sales”, but they certainly aren’t losing entire “leases”.

For people who lease the car, it really doesn’t matter.

I can’t imagine that with $5K free leasing cash toward 3 years leasing deal in Georgia that most of the LEAF aren’t leased there…

“Wanted: Leaf battery technician to fill recently and suddenly vacated position. Must have good ethics.”

I wouldn’t put this on the technician. Since the technician has no inventive to change the battery health indicator, my guess is that it was an honest mistake or the dealership instructed him to change it.

The moral of the story is: until Nissan puts a thermal management system in the Leaf don’t bother with it.

The Volt uses a similar chemistry. It has a TMS and its battery shows almost no fade. The Leaf battery fade is horrendous. Hopefully Nissan will either change the chemistry dramatically (not likely) or use a TMS.

Are your assessments “almost no fade” and “horrendous” based on some objective data, or just a reflection of your own bias and preconceptions?

I’m especially interested to know how you (and ModernMarvelFan below) assessed the Volt’s average, overall capacity loss. Please enlighten us.

Note that we’re talking here about the capacity of the whole pack, not merely the fraction made available to the driver (~60% in the case of the Volt), which can be increased as the pack ages. Thanks in advance.

Volt displays the kWh consumed.

If Volt loses more than 30% capacity, then the Volt won’t be able to allow regen when the battery is “full” b/c it won’t have enough buffers on top. So far, no Volt displayed that.

We know plenty of LEAF that has lost more than 30% of its capacity.

“which can be increased as the pack ages.”

How do you manage to do that while still keeping a proper buffer on the bottom and the top? I am curious.

The LEAF can do that by charging it “full” thus measuring the full pack voltage vs. charging current.

Since the Volt pack is “never charged to full” technically, it would have to be measured against a pre-determined characteristic of the pack. How does the computer manage that “accurately” without fully characterize the battery?

Please “educate” me about the ways of doing that since it sounds so easy to you.

The Leaf doesn’t charge to “full” either (nor over-discharges, for that matter). Like the Volt, it only uses part of its battery, just a higher percentage, close to 90%. Li-ion has this interesting property that cell voltage directly reflects SoC; unlike e.g. nickel chemistries, it’s monotonic (although not very linear esp at low SoC). Charge and discharge end with cells reaching a predetermined, but not necessarily fixed, voltage. The amount of “buffer” is usually simply how close to the maximum/minimum safe voltages the battery is allowed to go, and this results in more or less of the total capacity being available, in a predictable, reproducible way. Li-ion such as LiCo or LMN must not exceed 4.3 V/cell. Consumer electronics commonly charge at 4.2 V. With “100% charge” selected, the Leaf stops at 4.1, or “only” 90-some real %, and apparently this doesn’t change with age (there wouldn’t be much room to go higher anyway). Does anyone has data about the Volt? If I’m not mistaken, due to California emissions regulations, the battery of PHVs must be warrantied for 10 years and 150k miles, This is challenging, because for current Li-ion, degradation while slow is unavoidable and unstoppable. It’s therefore highly… Read more »

There have been studied showing no degradation. A story of one such study was even run here on InsideEVs.

There have been no reported instances of battery degradation, and even the highest mileage (EV and total) Volts have reported none. Combined with the studies, it is hard to refute that the thermal management system and added buffer is doing its job well.

This is in stark contrast to all the Leaf battery degradation stories we’ve heard, though it appears Nissan is improving their pack to address some of the issues.

Active thermal management, like the Volt, would go a long way to advancing battery life for the Leaf. Obviously the trade-off there is added weight, cost, and complexity.

Edit: Here’s the past story from here that I was referring to:

Thanks for the link ClarksonCote. Relevant bits: “[B]ased on a General Motors’ study of more than 300 Volts in service in California for more than 30 months, many owners are exceeding the EPA-rated label of 35 miles of EV range per full charge, with about 15 percent surpassing 40 miles of range.” “[M]ost of the folks who purchased the Volt at launch are still enjoying EV range performance on target with when they took delivery” This is a GM press release, so it’s certainly not biased against them. First, it seems super-generic. You could replace Volt with Leaf or any other plug-in, and those statements would be just as true. Now, even just in California, what about the remaining drivers, those not included in the “many”, “15%” or “most” above? Corollary: “After 30 months, many owners can’t reach the EPA-rated range, with about 85% failing to go 40 miles” “Many of the folks who purchased the Volt at launch aren’t enjoying on-target (whatever that means) EV range performance anymore” I find this discomforting, especially with the Volt only making about 60% of its battery capacity available when new. It should be solid, especially after only 2.5 years. The Volt only… Read more »

“With “100% charge” selected, the Leaf stops at 4.1, or “only” 90-some real %, and apparently this doesn’t change with age (there wouldn’t be much room to go higher anyway). Does anyone has data about the Volt?”

So, you are saying that you can measure the capacity by correlates to the pre-determined Voltage curve.

Perfect. Explain to me how you can determine the total capacity “loss” if Volt never charges beyond ~65% of the capacity? The charging voltage will never exceed that voltage unless the range is degraded beyond the buffer zone.

So, doesn’t that blow a big hole in your theory that GM engineer would slowly open up the range to compensate for the loss. How do they do that if they never charge beyond the pre-determined voltage?

I am waiting for your reasoning.

You misunderstood. Li-ion is charged at constant voltage, with a cap on current. The higher this voltage, the higher the usable capacity.
Same thing on the other end of the discharge curve: you can sip a little more energy by setting the cut-off voltage lower.

Using only a portion of the total battery capacity is done by charging at a voltage less than the maximum allowed, and/or setting cut-off more conservatively.
This percentage can be trivially changed at anytime by selecting other voltage(s). For example, when set to charge to “80%”, the Leaf stops at a lower 4V/cell.

In the case of the Volt, those end-of-charge / end-of-discharge thresholds are set closer together from the start, making only ~60% of the new battery available.
Simply raising the charging voltage and/or allowing deeper discharges would give access to the remaining 40%. The BMS can be programmed to do this very progressively,
as needed to keep the user-visible capacity constant.

Checking cell voltage at the end of charge and discharge would reveal if and when this takes place, and how much of the reserve capacity was tapped into.

“This percentage can be trivially changed at anytime by selecting other voltage(s). ”

What you said still has NOT explained when the car would open up more capacity or when that threshold is determined as needed.

By measuring the final charge voltage or lowering charging volt does NOT tell anything about how much capacity is lost. So, the computer wouldn’t know how much more capacity to open up unless you can measure the exactly amount lost to compensate. If you don’t, then you could potentially more capacity than otherwise measured.

How does the computer measure the capacity lost without fully charge the battery?

You still haven’t answer that key question.

“The BMS can be programmed to do this very progressively,
as needed to keep the user-visible capacity constant.”

By claiming this, you are saying that GM just “assumes” a curve and starts to open up the capacity without knowing the actual capacity lost. So, if the battery performs better, then you actually get slightly more range as the car ages?

I haven’t seen any evidence to show that. Doesn’t that sound silly that GM is just going to open up slowly without knowing the amount of lost?

No, the BMS doesn’t have to “assume” any specific degradation profile. The car already keeps track of the amount of energy which went in and out of the pack during the last cycle, if only for informational purposes: this data is shown on the dashboard.

Voltage thresholds adjustments can therefore be tailored accordingly, to keep the average available, user-visible capacity within a preset window.

Re active thermal management: yes I’m sure it helps, but only to a point. Remember it only works when the car is running or charging.

The most heat is ONLY generated when the car is on or running.

When the car is off, the heat is only as bad as ambient which is still far lower than the state when the battery is powered on.

That is the biggest issue here.

Perfect, that settles it then: the Leaf doesn’t need active cooling. Thank you, we’re done.

Not convinced? Let me explain. You’re saying that by far the biggest issue is heat generated while the car is running, right?

One of the most demanding yet realistic uses would be to drain the whole battery while continuously driving at highway speed.
The Leaf draws ~20 kW in those conditions, or ~50 A. Nissan used low-impedance cells, the internal resistance of the whole pack is about 0.1 ohm, so losses would total 250 W.

The Leaf’s battery weight about 300 kg. Going with a conservative specific heat estimate of 0.5 J/g/K, ignoring any heat transfered to the surrounding air, the above internal losses would cause at most a 6°C rise by the time the pack is fully depleted.


My guess is that Nissan engineers went through the same considerations, and decided against TMS.

A number of batteries later turned out to degrade much faster than designed/anticipated in hotter climates. Given how little temperature difference driving the car makes, I don’t think cooling those batteries down only during use would have significantly changed their fate.

“Perfect, that settles it then: the Leaf doesn’t need active cooling. Thank you, we’re done.” Is that what you got from my reply? Don’t you know anything about cooling? If you don’t, then we are done here for sure. “Not convinced? Let me explain. You’re saying that by far the biggest issue is heat generated while the car is running, right?” You are so wrong about this, it is almost comical to start correcting all your wrong assumptions. 1. Heat can be generated thru DCFC and high demanding charging and discharging. The amount of heat dissipated is directly correlates to its ambient. In the case of LEAF, if the ambient is already 50 deg C, then the packs itself will NEVER be cooler than 50 deg C. That is a key point of which you are completely missing. In an actively cooled car like the Volt, the battery can be cooled far below its ambient by using A/C compressor. 2. Your assumption of 20kW draw is false b/c it is average draw which doesn’t account for varying loads. The peaking of the current draw is what generates majority of the heat. That heat has very little chance of getting to… Read more »
“”You’re saying that by far the biggest issue is heat generated while the car is running, right?” You are so wrong about this, it is almost comical to start correcting all your wrong assumptions.” You were the one making that claim buddy, you forgot already? 😉 Up to a certain temperature, which you say is 60°C (plausible), heat merely accelerates capacity fade, well following an Arrhenius model [1.6~1.7x for every 10°C increase according to studies like this one ] Exposure therefore needs to be repeated or sustained to cause measurable degradation. I found the long highway drive, dissipating 900 kJ into the pack, to be the most demanding yet believable thing people would do on a regular basis. You’re welcome to come up with better numbers. But ok, “what if” we go with your crazy fairytale instead, with conditions worse than Phoenix record heat (as of 2010 at least) and somehow it was 50°C ambient for long enough for the battery to soak that heat then for someone to be racing and QC’ing (never mind some early-degradation Leafs didn’t even have QC), like SIX TIMES? Could that expose the battery to those dreaded 60+°C, or whatever is the… Read more »
Since I can’t reply to your comment anymore, I have to reply to my own to keep the thread going. I mentioned the 60deg C as the threadhold of which the battery pack will age signficantly faster or catstrophic. But it doesn’t mean at 58 deg C, it doesn’t accelerate aging. And you agree that fade capacity increases following the Arrhenius model. So, even if the battery packs sustains at 50deg C, it would have accelerated aging. By NOT having a cooling system, it means that battery pack is at the mercy of the ambient AND even after it is ON when it generates heat, it still can’t lower the overall temperature. That is why the LEAF packs ages faster b/c it sustains at higher temperature much longer than the system that has active cooling. Yes, the LEAF does cut back power to reduce “additional” heat added to the system when the battery pack is measured at high temperature (this just concludes that it does add significant heat when it is being charged or during driving. LEAF protects it by reducing the heat generated thru cutting power). Other system reduces the overall temperature regardless of ambient. The difference means two… Read more »

Again, numbers matter.

Imagine this pretty bad situation: 35°C ambient (Phoenix AZ average), 2 x 30-minute drive (harsher than highway driving, raising pack temp by 5°C if not cooled) and 3h charging per day (L2).

Let’s also assume the Volt always keep its pack to 25°C, which is likely optimistic, and that in both vehicles’ packs return to ambient in a few hours, like remaining 1h at constant temp after running.

Volt: 6h at 25°C, 18h at 35°C.
=> Following the Arrhenius model shown in the SAE study I linked earlier, cooling slows down aging by 14%.

Leaf: 3h at 40°C, 21h at 35°C.
(charging at 3~6kW generates negligible heat)
=> Self-heating accelerates aging by 3.3%.

Yes, TMS absolutely makes a difference, just not as much as you seem to believe.

Extremely Interesting ! Everyone is crying Foul – Fraud – Someone must have tampered with the LEAF’s Lithium-ion Battery Controller ! This presumes there is way to ‘set’ the bars – a very troublesome concept to me. Doesn’t the battery system display battery capacity bars based on real-time measurements on the battery pack? The idea that there is a way to manipulate information about the battery status is very upsetting to me. Please, if someone knows more about how it works, please share. Any chance this may just be a failure of the battery monitoring system? I’m not saying it was, just raising the possibility.

You can’t set the bars to an arbitrary value (the only choice is current or max, you can’t set it from 9 to 10). But you can reset them back to full 12. Every time you drive the car the system evaluates and updates the bar status. This will in time return to the true value if it was set to 12 for any reason. Unfortunately under normal use this will take months. So to recap 1 Car starts at 12 bars at factory 2 Car degrades to less than 12 bars in use 3 Car can be reset to 12 bars temporarily 4 Car will always return to correct value eventually The key is not to buy the car between #3 and #4 unless you are getting it for the same price you would get one of a known lower bar status. Target used options are modified if the car is near or above the 60,000 mile mark or the 5 year mark. 12 bars (never trust, even if not reset it should be treated as 11 bars, but might be lower) 11 bars (treat as 11 or 10 but know it might be as low as 8, treat… Read more »

Great Info.


DonC–I won’t argue against the early Leafs (2011 & 2012 models) having a cell chemistry that degraded much too quickly in hot climates, but there is also a very subtantial difference in the way Nissan and Chevy present the information. Nissan shows capacity loss on the dash display, whereas the Volt’s capacity loss is hidden. As I understand it, as the battery degrades in the Volt, it just uses more and more of that hidden capacity. There is nothing on the dash display that shows you this like it does on the Nissan.

“As I understand it, as the battery degrades in the Volt, it just uses more and more of that hidden capacity”

Can you explain your “understanding” again on how that is achieved?

BTW, do you know that Volt has both the buffer on top to allow “full charge” regen and buffer at the bottom.

So, if a Volt battery has lost more than 20% like some of the LEAF, then you would have no more “buffer” zone at the top. NO Volt has seen that.

So, we know for sure that NO Volt has lost nearly as much SOC as a LEAF in %. That statement is absolutely true.

The Volt battery is rated 16 kW*h (or a little more on younger model years) when new, and the driver can access the center 10 kW*h or so (again depending on MY).

As far as I know, there is no visible indication, on the dash or elsewhere, about the actual, current total capacity, or how much buffer remains on either top or bottom SoC, so drivers have no way to assess those.

As I very much doubt you have documentation showing how much of those 6+ kW*h of reserve are indeed still there after several years, let alone on a large-enough sample of cars, please tell us on what data your claims are based on.

Volt allows a hybrid buffer after the 10kWh is drained. It is ~1kWh. You can figure it out by draining the gasoline tank and drive with with battery until it is drained. It will cut back performance, but still tracks the total kWh consumed. Volt allows the full regen (up to 1kWh) even when the battery is full charged (unlike LEAF and other BEVs). So, even if Volt battery degrades, it still maintains the two buffer. That is 12kWh out of 16kWh usable range. Let us say that Volt battery degrades. But we don’t know how much, but we do that once it loses more than 4kWh out of 16kWh, we will start to notice. 4 out of 16 is 25%. We know plenty of LEAF that has lost more than 25% capacity. Is there any evidence to show that Volt lost more than 25%? We know that at least one Volt has over 70K electric miles by now, right? Now, let me ask you this, how does the Volt open up the capacity over time without “properly” measure the entire pack capacity? Is it by measureing voltage? Does it just shove 10kWh into the pack regardless? If that is… Read more »

Not overcharging Li-ion only implies keeping voltage below what is safe for the specific chemistry used, irrespective of capacity or age. It’s completely straightforward, much simpler than other chemistries.
See also my other reply above.

io, DashDAQ readers allow owners to read their true state of charge without the buffer factored in, if they choose to do so.

The most avid Volt owners (i.e. the ones that use their batteries the most) have done this and no degradation issues have been reported.

The greater buffer and active thermal management is doing the job of protecting the Volt’s battery quite well.

What makes you think that she isn’t getting the lizard pack? As far as Nissan has stated, all 2015 replacement packs and packs going into 2015 LEAFs are the same.

Now I really don’t understand the Leaf’s battery display!. Mine has lost 2 bars, but if I plug it in and allow it to, it charges to 12!, past the 10 bars it shows on the battery capacity… Anyone can explain please

Regardless of the bar, do you actually have the total range when you charge up to 12 bars?

I don’t often use all the range, except my favorite beach is 100 miles away over two 2000 ft climbs, which, as you can imagine, takes hypermiling ultra, but it has done that 4 times. Another trip is indicated, hopefully over the Christmas season, so I will report. My sense is that the range hasn’t fallen, certainly not 2 bars worth. Some great discussion here.

The small bars is the battery’s capacity. The larger bars are showing state of charge of that capacity. 12 bars is a full charge, full is as full as the battery can hold. If your 12 gallon tank has been reduced to 10 gallons the gauge still shows full, but now full is only 10 gallons.

So, here is another fact that at least anther 2011 LEAF has lost 4 bars out of 12 bars in just a little over 3 years… 1/3 of its capacity in Southern California condition.

Yes, it is great that it is covered under Nissan Warranty (after all the early adopters fought Nissan about it). The fact still illustrates that the problem is still there depsite all the early LEAF fan’s denial.

Granted, everyone has claimed the 2013 and 2014 batteries are better. Are there any real world studies to back that up? There were plenty of various owner studies and government studies on the LEAF packs from 2011 and 2012 models.

Are there any studies ongoing on the 2013 and 2014 LEAF?

My 2 cents? Nissan produced a great car, but I don’t think they were thinking long term.

They chose to cut costs at the expense of a properly managed battery over all temperature conditions, and many bars of degradation are the result.

In the short term, they’re selling more EVs due to the lower price. I just hope that this doesn’t substantially affect the reputation of EV’s in a negative way.

There’s already enough misinformation out there, it would be sad to have the best selling EV cause everyone to believe that the batteries lose too much capacity over the life of the car to maintain utility.

And yet Mitsubishi i-MiEVs in the same climates are not losing capacity. VW also chose not to use active cooling in their batteries, finding it was unnecessary. We’ll see if that’s true, but to put a blanket statement out there about active cooling isn’t necessarily accurate.

That could be due to few things.

1. I-MiEV is at least air cooled. Nissan is adding that to its e-200 and e-Golf is air cooled as well.

2. Power demand and DCFC. The lower the output requirement, the less heat it generates. The slower it charges, then less heat it generates. So far, we have no data on E-Golf yet and I-MiEV has very few data point to be conclusive…

3. This can be observed by the fact almost all PHEV/ERVE/BEVx and higher power BEVs have liquid cooling due to high C discharge and charge (regen) rate. That generates a lot of heat for short period of time. Thus require higher cooling.

Didn’t the 2013 LEAF get a performance “downgrade” over the 2011/2012 models? That would reduce heat generation. LEAF also changed something around the pack area that caused the 2013 model to lose the 5-star NHTSA gov safety rating that 2011/2012 had.

I think there were stories here, citing inside info about Nissan upper brass rushing the Leaf to market over the engineering teams’ protests. They wanted a bit more time to stabilize it.

It seems that with the 2013 model, the engineers got what they could/wished to add into the Leaf. Sure, too early to tell about battery longevity for the 2013+ cars, but it adds up.

Any business decision is a tradeoff. As long as they don’t put lives at risk, teething problems for a new technology are all but inevitable. Environmentally and economically, if they manage to pull off a resilient battery-pack without active cooling, it’s definitely a winner.

All that being said…I would not trade my beautifully fugly Leaf for anything….until the model 3 comes out…then I am dropping her like a hot rock on Carmax…

Almost 50,000 miles on mine and it still has all 12 capacity bars, no complaints here.

I wouldn’t be so quick to congratulate Nissan for their handling of the situation. Remember, only a Nissan-trained tech could have reset the battery counter in the first place.

And they didn’t even provide Jennifer with the latest battery version. It’s probably a refurbished unit they had sitting on a shelf that will die prematurely anyway.

I’m sure Nissan could track down where it was tampered with if they really wanted to. There’s a record of it having three bars gone and then… it didn’t. How many service centres could it have visited between the two periods?

However, if Nissan were to discover this occurred at one of their dealerships, they might be liable for any other people they’re ripping off.

As much as I criticize Nissan, the Nissan dealers are independently owned. This is why Tesla doesn’t want dealers.

It would certainly damage Nissan image though.

As far as the cells go, Nissan warranty only guarantee to fix the battery so it meets the minimum of the capacity, NOT a 100% full capacity. So, it is true the replacement deal isn’t all that great but it is certainly better than NOT having a capacity warranty.

It’s my understanding that the replacement is a new battery , regardless , Im not upset with Nissan , however I do think they need to be aware that this resetting of bars is a potential problem and for me it was a very real problem, there are risks she buying a used car , but this to me is the equivalent of rolling back the odometer . Not sure if it was the dealer or a previous owner , etc.. But there needs to be a way show true battery capacity in the used EV markets.

I am looking for A new battery (brand new) for nissan leaf 2015 but the dealership is very expensive if anyone know where to get a brand new battery write me thank you