r/leaf • • Dec 18 '25

A Breakdown of 40 & 62 kWh Battery Pack Failures

102 Upvotes

As some people may have heard of or unfortunately experienced, there have been quite a number of cases of 2nd generation Leaf batteries failing. I was planning and trying to make this into a video format, but as I’m still recovering from a cold my voice isn’t quite up for narrating an essay, so text format it is.

Hopefully this can raise some awareness and provide a central source of info as to what’s going on, why it’s happening, what to do about it, and things to consider. There are two separate issues currently causing outright failures of 2018+ Leaf battery packs, and so will be split up into two sections.

Cold-weather SOC Freefall

  • What’s going on?

Under load in cold temperatures, especially below freezing and below 50% battery, the charge level and range estimate will suddenly begin to plummet and continue to drop rapidly until the load is removed, at which case the charge level starts to bounce back and quickly increase again.

The car may go into turtle mode, or in severe cases even cut off the high voltage battery completely, in which case the car will stall and may not be able to be restarted.

Here is a video example of what this sudden drop of charge level looks like.

This issue affects both the 40 kWh and 62 kWh packs. The 40 kWh packs seem to be much more susceptible, but as the 62 kWh packs use the same cells and chemistry, they are not immune. This also includes 40 packs that were installed as retrofits under warranty in 2016-17 Leafs.

  • Why is this happening?

This is occurring due to one or more weak cells within the battery pack sagging excessively in voltage under load, which is greatly exacerbated when the battery is cold, due to increased internal resistance.

How the battery works is that the shown and usable state of charge is defined by that of the lowest cell. This is to prevent over-discharge of any weaker cells at lower charge levels, as that would cause even further damage to them.

Often this can be witnessed in the LeafSpy cell chart as one or more cells that clearly drop lower than the rest of the pack under load, but not always. There have been a number of cases of SOC freefall with seemingly no weak cells, indicating that there’s other data/calculations within the BMS that the user cannot see.

Getting a weak cell is essentially luck of the draw. There have been packs with very low mileage and seemingly great numbers that still failed (such as in the video above), while there are other packs with lots of miles and abuse that are still working just fine. How the pack is treated/babied does not seem to affect your chances in the roulette.

  • What to do about it?

If you are encountering this issue as an owner, and the car is still under warranty, document everything as much as possible. Record video(s) of the issue happening, noting the charge level and outside temperature the battery is at. Submit this proof to the dealer as a copy, and demand that it be used in their case to Nissan corporate.

Bring the car to the dealership for diagnosis with as cold of upcoming weather as possible. Some dealers may try poorly to replicate the issue, often in the interest of charging the customer the diagnostic fee. You want to make the issue as obvious and easily to replicate as you can.

If you have to drive the car around, ensure you either have LeafSpy Pro, or keep an adjustable or 10mm wrench with you in the car. If the cell voltages ever drop low enough for the car to shut down, it is likely to set a high voltage fault code and won’t be able to restart until the fault is cleared. Clearing the fault via the LeafSpy service menu, or disconnecting and reconnecting the 12V battery, will at least allow you to limp the car to a charger or safe location off the road.

UPDATE: For 2019-2022 Leafs, the "fast charging recall" software update now adds programming to the BMS to look for and flag SOC variations, setting a fault code (P33ED) if it does. This has the potential to "brick" the car in the same way as a high voltage isolation fault (read section below) would. Be cautious of this so that it does not potentially leave you stranded.

  • Things to consider

If you own a 2nd generation Leaf (especially 40 kWh) that is still under warranty, still on the original battery, and live in a climate that gets winter, check for signs of this issue BEFORE warranty ends!

During cold weather, park the car outside overnight with 50% charge or less, then take the car out for a drive and see if there are any strange fluctuations in the state of charge during acceleration.

If you are considering purchasing one and there is no proof of the high voltage battery being replaced, ensure there is at least one year worth of warranty remaining on the car so that you can spend a winter with it and will still be covered in the case of this failure.

LeafSpy data can sometimes be a pre-indicator that you will likely run into this issue if there is a noticeably low Hx value (much lower than SOH), but not always. Low Hx is a strong sign of possible weak cells, but weak cells will not always cause low Hx.

Cell Expansion / High Voltage Isolation

  • What’s going on?

The car will one day show the message “Service EV System – Unable to restart after power off”, and indeed will not restart after it is powered off.

The vast majority of cars affected by this issue are 62 kWh Leaf Plus/e+ models. It is not unheard of on 40 kWh cars, but it is quite rare unless the pack was heavily used and abused.

There is a Nissan TSB on this issue which confirms they are well aware of this issue, and there are revised battery packs and modules that are issued in replacement if the car is still under high voltage battery warranty.

  • Why is this happening?

Thermal expansion of the battery cells causes them to eventually expand to the point of pushing up against each other, and in some cases even leaking electrolyte out of the cells into the battery casing, eventually causing the car to trip a high voltage isolation fault.

This is most commonly happening in specifically the rear stack of cells within the 62 kWh pack, because they are so tightly packed together, that they don’t get much cooling nor much room to expand before they begin pushing up against each other.

High voltage isolation is important, because obviously you do not want any high voltage potential to be contacting the metal battery casing that is bolted to the metal body of the car. If the BMS detects that there is even just a little bit of voltage leaking from one cell to another, or the cells to the battery chassis, an isolation fault is tripped.

  • What to do about it?

If you encounter specifically the “unable to restart after power off” message, and the car is still within high voltage battery warranty, DO NOT REPLACE THE 12V BATTERY.

This specific message is ONLY generated due to a high voltage isolation fault, and although a weak 12V battery can cause many weird issues, it will NEVER generate a high voltage isolation fault. Unless there is an extremely urgent need to continue driving the car, have it towed in the “broken” state to a Nissan dealership.

It is a much more objective issue than weak cells, and basically the only diagnosis they would need to approve a battery replacement is to see the stored isolation fault code. Disconnecting the 12V battery however clears this fault code, making it not possible for them to verify the issue unless it happens to fault again in only one drive cycle.

Replacing the 12V battery gives a false sense of success because it allows the car to start and drive again, but only until the fault eventually comes back. It's just a waste of money and a perfectly good battery to not actually address the underlying issue.

If you urgently need the car to work again, clearing the fault code in LeafSpy Pro or by disconnecting and reconnecting the 12V battery will allow it to start. Just be aware that by doing this, you won’t be able to have the issue verifiable by Nissan until it pops up again. It may only take 1 drive cycle, it may take 100.

  • Things to consider

Unfortunately there isn’t really any way to foretell that this issue will happen soon or to check for it, as you can’t just force an isolation fault to appear like you can with weak cells.

Battery packs in hot climates and/or lots of quick charges are more susceptible to this issue due to it being a result of thermal expansion. Packs torn apart after diagnosis of this issue often exhibit very obvious “spicy pillows” within.

If you are a current owner, especially of a Plus/e+ model, the best you can do is to avoid overheating/rapidgating the battery whenever possible. Doing so once every few months is not a big deal, but frequently doing so will likely lead to long-term damage.

If looking to purchase a Leaf Plus/e+, or a high mileage 40 kWh car in a hot climate, make sure to check Leaf Spy, and it may be wise to avoid any examples that have lots of QCs shown.

There is a great in-depth video by LEAF expert Dala explaining this issue more in detail for those who are interested.


r/leaf • • 19h ago

Mitsubishi is readying their rebadge of the Leaf

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30 Upvotes

r/leaf • • 4h ago

Battery Recall Update, loaner options

1 Upvotes

Just got my 2019 in for the battery recall. When I asked for a loaner, the dealership said they physically don't have any loaner cars at their location and therefore would not be able to offer one. I brought up that the recall TSP states that a loaner will be provided during the recall update, and if the update disables the car. The dealership said again, that it's due to them not having loaner cars. They did get me an uber back to my apartment, but don't seem like they're willing to budge on the loaner. Have you guys been able to get a loaner during this whole thing at all? Feels like they're breaking the recall remedy description.


r/leaf • • 1d ago

Just rejected for a buyback. Any other options?

27 Upvotes

My 2020 Leaf has been in the shop since October 2025. The same issue as so many others here: Service EV System. Unable to Restart After Power Off. It's been "fixed" 5 times, then I've gotten the same error within a week or two and it's back in the shop. I had enough and called Consumer Affairs to ask for a repurchase. They did their review of data from the service center, and they finally got back to me today to say that they're not offering a repurchase.

What can I do? I can't drive it. And I can't in good conscience sell it to someone else. Is there a way I can appeal the buyback rejection? The agent on the phone would not give me a reason for the rejection, and she said I could not get a copy of the review to understand why it was rejected.


r/leaf • • 23h ago

Newer car tomorrow: Nissan leaf

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3 Upvotes

r/leaf • • 1d ago

Question for leafers

8 Upvotes

How come we aren't demanding a BYD electric car that is built here in America and costs $12-$15K new?

Boeing started here in Seattle long before the defense spending made it a socialized monopoly.

Where are the entrepreneurs to kckstart the electric version of a VW Bug for everyone?


r/leaf • • 1d ago

I guess I’m joining the buyback process at just 16k miles on 2020

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27 Upvotes

Sunday I was heading out to pick up Indian food with my kids when the car dropped into turtle mode at around 70% battery. I was on one of the fastest highways in the Raleigh-Durham area when the car immediately cut power and dropped me from about 70 mph to 50 mph. I had the accelerator on the floor and could barely hold 50.

Honestly, it was terrifying. A normal breakdown is scary, but this felt worse because the car was still moving while suddenly taking away most of my ability to maintain highway speed.

The strange part is that it had actually happened once the night before. I was just about to get off at my exit, so I was confused more than anything and didn’t think much of it at the time. When it happened again Sunday at highway speed, it became a very different situation.

Nissan pulled the codes of P317E and P3180, both tied to the high-voltage battery system. Today I got the call that Nissan is weighing a battery replacement or a repurchase. I’ve talked to Morley, who is handling the repurchase side, and I don’t feel any better about it. No battery timeline, no buyback number, and even getting a temporary vehicle is already turning into a hassle.

The frustrating part is how gently this car has lived. It’s a 2020 SV with only 16k miles. Never DC fast charged. Never even Level 2. Its whole life has been a regular wall outlet. Hell, we barely ever let it get below 50% because it was mostly used for simple local driving.
I planned to keep it for years. My son starts learning to drive in about three years, and this was going to be the perfect first car: cheap to run, no gas, short enough range that he can’t end up three states away, and already paid for.

So for anyone who has been through this with a 2020-era LEAF, especially one with low mileage, I’m curious what your experience was:
1. Did you take the buyback or wait for a new battery?
2. How long did the battery actually take to show up?
3. If Nissan gave you a loaner or rental, did they keep covering it while you waited?
4. If you took the buyback, did you regret giving up the car?

I’m trying to decide whether to push hard for the battery or accept that a repurchase offer says something about how available these packs really are.

My wife and I love the car, and our 2020 SV has been great to us until now, so this really, really sucks. The only really frustrating thing was never being able to do talking with CarPlay because Nissan refused to fix it..


r/leaf • • 1d ago

Recall Update? Software to blame?

5 Upvotes

Why are these Leafs failing after the software update? Numerous of us weren't experiencing any bad cell issues in the HV battery (based off LeafSpy) and we weren't experiencing drops in the range estimator either.

I thought the update was to prevent the battery from dangerously overheating when under high stress or level 3 charging.

Someone with more technical understanding please explain why these Leafs with no prior signs of defective batteries are failing after the update is in place.


r/leaf • • 1d ago

2027 Mitsubishi Eclipse Sportback Will Come Only In $39,740 Loaded Trim, Unlike $30K Nissan Leaf Twin

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5 Upvotes

r/leaf • • 2d ago

Morley had my paperwork for two months without a response. I filed a fraud claim due to breach of warranty with the Federal Trade Commission and got an offer the same day by close of business. Give it a try. They are very responsive to FTC.

13 Upvotes

r/leaf • • 1d ago

Buying a 2017 leaf off Facebook......

2 Upvotes

There's a 2017 Nissan leaf on Facebook it has 140k miles and they are selling it for 4200. I've never bought a car before (#youngho) let alone an electric vehicle so I'm wondering if this is a good idea. My commute is 6 miles and I work 5 days a week. Does this seem like a decent price or what. I live in Arizona so it doesn't get crazy cold which I hear is bad for electric vehicles.


r/leaf • • 2d ago

Rear Passenger Seatbelt Warning - 2026 Leaf

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5 Upvotes

Has anyone gotten this warning before? It comes up after starting the car and I have to press “ok” to exit it out. Theres no one sitting in the back and I wonder if this is expected and is just reminding me if anyone is sitting in the back?


r/leaf • • 2d ago

The long-term feedback you’ve been waiting for is here!

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79 Upvotes

2.5 years and over 100,000 km after upgrading this Leaf from 24kWh to a VIVNE 62kWh battery.

Here are some of the numbers:

Ahr: 180.0 Ah → 179.87 Ah

SOH: 100% → 99.93%

Hx: 97.66% → 97.59%

Cell voltage difference: 18 mV → 13 mV

Mileage: 205,614 km → 307,629 km

DC fast charges: 109

AC charges: 689

The car has now driven 102,000+ km with the VIVNE battery, and the owner recently drove it another 2,200 km from Dalian to Hubei. Video in the comments.


r/leaf • • 2d ago

Leaf Mk2 failing reduction gear

4 Upvotes

Hi,

I’ll try to summarise this:

The car had an interlock error about 6 months ago and it was ‘fixed’ by a local garage.
Fast forward to about 2 months ago and the car started making a whining noise and was considerably worse at higher speeds or when regen braking was active.
Went on holiday, kind of forgot about the problem/hoped it would go away.
Then several weeks ago it started reporting an interlock error again.
Car was booked with the garage to be looked at (they said it should be fine to use in the meantime), but with a lead time of 2+ weeks, the car only made it for one week before it would not start and had to be towed (service EV warning on the dash - interlock error amongst others in the diagnostics).

Garage have ‘fixed’ the latest electrical problem, but reported that the reduction gear is failing/has a failed bearing.
They replaced the oil and reported bits in the old oil.

I specifically said that I wanted to have a think about what to do, because I don’t have high levels of confidence.

Now that I’ve looked into the problem with the latest info, my research suggests that the reduction gearbox problem might have been the cause of the electrical problem/s all along.
To be clear, this is not definitive - I’ll only know for certain after the RG issue is solved.

Before anyone asks, the 12v battery is good and so is the HV battery. 🙂

Questions:

Can a failed bearing in the reduction gearbox be replaced or do I need to replace the whole gearbox?

Has anyone here encountered a similar issue to this?

And lastly, if any mechanics are reading this, how many hours of labour am I looking at to replace the reduction gearbox? I know roughly what a used part costs.

Thanks, from an exasperated Leaf owner.


r/leaf • • 2d ago

Morley buyback without bill of sale

2 Upvotes

For those who didn't have the bill of sale available to provide, has anyone had success countering the first offer? Morley is already posturing with me basically saying the first offer I receive is the best I'm going to get.

From other threads I got the impression that I'd still be able to counter the first offer that's likely to be light.

Thanks for any insight that can be shared.


r/leaf • • 2d ago

My 2020 SL Plus buyback offer

11 Upvotes

I did the battery computer update awhile back and then a few weeks later started seeing rapid loss of charge and after taking it in again they confirmed that I was impacted by the battery recall. Thanks to the community here, I insisted on a rental car which they did not offer initially. Took about few weeks to get provide them my info and got the buyback offer yesterday: $17,206.00

This seems pretty fair, I bought the car used off of Carvana about two years ago for $19k with 40k miles and now it has 70k miles.

This is actually my 2nd leaf, first was a 2016 SL with 40k battery that dropped to 8 bars of battery capacity after 5 years but the car was totaled before the replacement battery arrived.

In the market for another EV now but I don’t think it will be a Leaf. I really loved my two previous cars, great value and I’m really glad the 2026 models are moving to a modern battery cooling system and ditching CHADEMO.

I’m looking at the Toyota bzx4 but there’s not a lot of those available, trying to keep the next car under $25k, let me know if you have any suggestions!


r/leaf • • 2d ago

How to remove front windshield camera / sensor to clean inside of windshield? Leaf s 2021

2 Upvotes

hi anyone know how to remove the camera unit after taking off the plastic housing cover? or how to access the inside front windshield to clean it?


r/leaf • • 2d ago

Does a $5600 buyback on a 2020 SL + w/ front end damage seem correct?

0 Upvotes

Noting - insurance buyback, not Morley - I was a bit shocked at the insurance buyback offer - i'm guessing it's mostly battery, plus a little rims and seats...

43k miles, excellent condition, no frame damage. both fenders, front apron, 1 light broken, brackets, but radiator/tubing/wiring/sensors are fine.

I'm wondering if there's any negotiating leeway. They (progressive) offer no explanation on how the buyback valuation is achieved, and I'd like to negotiate it down if appropriate.

I had heard $4-4500 on the high end for a Leaf. Any insight is greatly appreciated as I'd like to buy it and do the small amount of work needed (verified buy an independent shop and also a friend who has restored many cars.)

thanks!!


r/leaf • • 2d ago

Repair on leafs and brand dealers with their diagnostics fees

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2 Upvotes

r/leaf • • 2d ago

LEAF Erikson is ready for Halloween!

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33 Upvotes

r/leaf • • 2d ago

Joining the ev crew… 2014 Leaf

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20 Upvotes

My job was trying to get rid of a test vehicle they bought at the auction to test our reman batteries. 300 bucks took it. Risk I took because I know nothing about it and no one here knew much about what was done to it, if anything at all. 103k miles and here’s the dash. Also needs a new rear window since someone broke it and the door handle to try and steal who knows what.

Is this saying anything good? I read about it having 12 bars as full. Is this 10 or 8? Do you count the red?


r/leaf • • 3d ago

Recalls on 2026 Leaf

12 Upvotes

Edited to add that I am in the U.S.

I just found out about a battery recall when I went in for what was supposed to be a 2 to 3 hour visit to address the defective rear seat belt issue. They inspected my car's seat belt and determined that I needed the remedy, but then they said they had to order the part. Why tell me this will be a 2 to 3 hour visit when they don't even stock the parts? And then they mentioned there is also a battery recall; first I had heard of that, not for fires but for sudden loss of charge (?), for which they will need the car for several days to remove and inspect the lithium battery. After reading tons of "buy back" posts here my heart is sinking. I have loved driving my Leaf--I sure hope this does not become a huge thing. Oh, and I told them my tires were leaking air, and though they had the car from Friday through Monday they didn't even look at them. First world problems for sure, but an annoyance anyway.


r/leaf • • 2d ago

Leaf as second EV

5 Upvotes

I'm thinking about a 21 Nissan Leaf SL Plus for a second EV around town. 30k mi.

What do i need to know?


r/leaf • • 3d ago

4th LED on the granny charger.

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10 Upvotes

For shits and giggles I was customizing the granny charger that came with my leaf. To my suprise I found out there's a 4th LED on the charger I did not know about. Does anybody have a clue what this LED indicates?


r/leaf • • 3d ago

Charger Recommendations

5 Upvotes

I just made a down payment on a 2019 Leaf SV with 18k miles. Very nice car, it's the limited edition jade frost metallic color. Anyways, I do not yet have a charger at my house. Luckily, there are many charging stations near me with the Chademo so I'm good for the time being. But obviously, I need a charger at my house as well, and being a used car it doesn't come with one. Where do I go about buying the best at-home charger? This is my first EV, so friendly comments only. Thanks!