Battery Degradation of a high mileage Leaf

[Oostenrijker]

Hello there,

I recently bought a second hand Nissan Leaf Tekna from 2019 and now it almost has 180.000km's on the odometer. In the beginning I didn't wanna bother with Leaf Spy, and still I don't use it actively.

However I have found out some interesting things: the degradation with a Nissan Leaf is mostly time based, so no matter if your Nissan Leaf from 2018/2019 has driven 180.000km or 50.000km totally. The degradation is atleast going be 11% after 4 years.



Mine however has a degradation of 15% roughly: a month ago it was still 16% but now the SOH is all of a sudden higher, which I kinda expected. The previous owner was a leasing costumer, who drove a lot.

That didn't scare me off buying a high mileage Nissan Leaf: because it saves quite some money, and the state of the car is almost as new. It also has no issues at all, and I still manage to drive more than 200km on a full battery.



The only think I found out today is: when the SOC gets below 10% it often would start dropping very quickly, in comparison to the drop from 100% to 10% which goes normal.

Basically it's a bit unstable: 8 out of the 96 battery cells, that are displayed in Leaf Spy are supposedly "Weak Cells" and I did some searching about this.

It seems to be quite common with high mileage EV's: and I have already driven the Leaf to 0% several times. Where I witnessed, that the SOC would drop first from 8% to 5% for example. And finally to 0% which increases the range anxiety. But then all of a sudden, it would jump back to 3% for example.

The explanation would most likely be: below 20% SOC the battery cells aren't that balanced anymore, and the BMS might try to balance it more. But in the end it's the weakest battery cell, which will activate turtle mode when one of the cells gets below 3volt?

I'm not sure about it: but just searching on Google, I can see it's not something unique for only Nissan Leaf. It does occur at Ioniq's as well, despite those EV's having a higher SOH usually.

So getting a highly mileage Nissan Leaf is totally fine: but don't trust blindly on Leaf Spy. Because according to Leafspy, I still had 16.9% SOC left. But I have no idea, when Turtle Mode will actually kick in?

But I still had 6kWh left in my battery, which should be in theory enough for another 50km's. Because my average consumption is 12.3kWh/100km.



Today I actually did 11.7kWh/100km and from 100% until 0% I drove 227.7km. But it includes some city driving of the last few days, as I charged to 98% on Monday.

 

[LeftieBiker]

Welcome.

But in the end it's the weakest battery cell, which will activate turtle mode when one of the cells gets below 3volt?

Yes, it's the weakest cell that determines both the range, and how much of that range you can use. For this reason I'd advise against getting a Leaf with weak cells, unless the worst case range projection suits your needs well. I also would not get one with weak cells with the expectation of driving it for many years.

 

[Oostenrijker]

Welcome.

But in the end it's the weakest battery cell, which will activate turtle mode when one of the cells gets below 3volt?

Yes, it's the weakest cell that determines both the range, and how much of that range you can use. For this reason I'd advise against getting a Leaf with weak cells, unless the worst case range projection suits your needs well. I also would not get one with weak cells with the expectation of driving it for many years.

After I charged until 56% the cells get balanced, so it isn't a big deal.



Just I'm not sure how long I can keep driving, when the car reports 0% but Leafspy says 16.9% and 6kWh left. I simply won't risk it. Although I know there is definitely some reserve and today, I still had to go about 6 a 10km when the car showed 0% battery.



I don't frequently charge until 100% but last time when I did, the battery cells where nicely balanced and I found out that my battery pack contains 32.5kWh totally.

And I still get more than 200km of range, so I'm totally happy with it.

 

[cwerdna]

However I have found out some interesting things: the degradation with a Nissan Leaf is mostly time based, so

Yes, but also climate and high state of charge can also have an effect.

See my pointer near the end of https://mynissanleaf.com/viewtopic.php?p=632690#p632690. From your graph, it seems likely your rear stack is much more degraded than the rest for exactly the reasons described there.

 

[Oostenrijker]

However I have found out some interesting things: the degradation with a Nissan Leaf is mostly time based, so

Yes, but also climate and high state of charge can also have an effect.

See my pointer near the end of https://mynissanleaf.com/viewtopic.php?p=632690#p632690. From your graph, it seems likely your rear stack is much more degraded than the rest for exactly the reasons described there.

I read something like that already: it had about 300 something QC's, but I don't consider that extremely a lot. 4 years have 1460 days, so it wasn't daily fast charged.

As long the battery still performs well, than I'm not to worried. The car has a year warranty. But personally, I tried to avoid fast charging as much as possible. Or use the free ones, which are limited at 20kw.

I would consider replacing the battery in the future, if prices drop and perhaps better aftermarket batteries get on the market. But as long as it does the job, I won't be replacing it.

 

[Oostenrijker]

They dealer gave me today an Nissan Micra to borrow, while they are replacing the windshield. What a sh*t car it is, compared to the Nissan Leaf.

Also there is a recall now on the Nissan Leaf: which all of a sudden, I start wondering if I can still get the recall done. Even though the warranty is already over.

 

[goldbrick]

The last recall on my Leaf was an errata sheet for the owner's manual. If that's the case for you, Nissan will mail it to you if you don't take the car to the dealer.

 

[knightmb]

Also there is a recall now on the Nissan Leaf: which all of a sudden, I start wondering if I can still get the recall done. Even though the warranty is already over.

Recalls always override warranty because if the recall was for something that could hurt or kill someone and the dealer refused to do the work because of warranty and then said person got hurt or killed because of lack of recall work, you see where that legal mess would end up court wise.

 

[Oostenrijker]

Also there is a recall now on the Nissan Leaf: which all of a sudden, I start wondering if I can still get the recall done. Even though the warranty is already over.

Recalls always override warranty because if the recall was for something that could hurt or kill someone and the dealer refused to do the work because of warranty and then said person got hurt or killed because of lack of recall work, you see where that legal mess would end up court wise.

Yeah I read something like that: basically they try to protect there image. But what I don't really like, is the difficulty to get this appointment for the recall.

One staff member of the Nissan dealership suggested: it could be done during regular maintenance. But I have no wish or plan to bring a bag of money yearly to the dealership.

I rather do the maintenance myself, or just go to the tire garage for replacing tires. Much more I don't need to care about: I'm sure they would be able to replace brake fluid as well. That's not something, I need to go to the dealership for.

Also because of sloppynish of some of the workers nowadays: after the windshield replacement, there was rubber dirt from the windshield replacement on my dashboard. Which I had to clean away by myself, because obviously they are sloppy.

But I rather have this recall done this year: because it makes me feel uncomfortable, to basically tell them I don't plan to follow their maintenance. If I wanted to do something like that, then I would have stuck with an ICE.

That money, I wanna keep for a potential battery replacement: touch wood, I hope it will never been needed as long as I own it.

 

[kaiat]

My Leaf has only been to the local Nissan-dealer twice during my years with the car. Once for a recall and once for bodywork after another car hit it while parked at a shopping mall. I do all the maintenance and most repairs myself. There was no problem when booking an appointment for the recall. Didn't have to pay anything and the car was well out of warranty.

 

[Oostenrijker]

My Leaf has only been to the local Nissan-dealer twice during my years with the car. Once for a recall and once for bodywork after another car hit it while parked at a shopping mall. I do all the maintenance and most repairs myself. There was no problem when booking an appointment for the recall. Didn't have to pay anything and the car was well out of warranty.

I'm in the autism spectrum, and I do find the visits to the dealership troublesome: now they replaced my windshield. However they did a bad job....

It turned out my windshield already had a scratch on the outside: first I thought, it's just a dirt. But when I couldn't wipe it away, then I discovered it's a scratch. So now I'm waiting on their reply, because I have told them I'm very unhappy about this.

They didn't clean the car of the mess they created, while replacing the windshield: I had black fingerprint on my startbutton and in the end, I found out that the windshield has a stratch. Perhaps caused with a tool, by one of the working people?

I don't know, but I'm guessing: now they probably going do it all over again? So then they can do that recall as well. Because I feel really uncomfortable, telling them straightforward I have no plans to follow the maintenance.

Because when I sold them my old car to them, which I had just given for € 400 maintenance. It didn't get me a penny extra and I honestly believe, it won't make a difference either when in three or five years I'm going sell the Nissan Leaf. It has run more than 180.000km and in 3 years, it surely going have about 215.000km's.

So I will do any maintenance myself, of just go to another garage. No need to go yearly to the dealership: those cost for the little maintenance they do, is really ridiculous. Most of the inspection is done during the MOT anyway ( APK in the Netherlands)

 

[Oostenrijker]

I'm starting to get a little bit more concerned about the battery pack of my Nissan Leaf: on purpose, and because I enjoy driving the Nissan Leaf. I have been driving a lot.

Now 10.000km's and no big issues: the SOC just gets really unstable, once I go below 8% SOC. But I have only once seen this EV Engine light go one, that was after trying to use a not working Shell Fast Charger.

But sometimes I wonder: would it be a good idea, to try and drive the battery as empty as possible with Leafspy? The weak cell's only showed up, after I drove it down to 17.9% real SOC as reported by Leaf Spy.

Some time ago though, the battery percentage dropped very fast after accelerating full speed, but afterwards the battery percentage went back up like more then 5%. I usually drive very conservative, and do not accelerate fast at all.



At 66% SOC ( Leaf Spy shows 67.6% ) nothing seems wrong: although at 50mV I can still see, that rear pack of cells have a lower voltage. But it's only reported as 18mV difference, so that isn't to bad.

The reason I'm all of a sudden more concerned, is because of some other issues I'm having with this Leaf. During replacing the windshield, the workers made the dashboard all dirty. And yesterday I discovered, my roof textile is slightly damage. With also the black rubber showing, the proof that it was caused during changing the windshield.

So I'm unhappy with this and in the meantime, I have expressed my other findings as well. It had damage at front bumper, which I found out. Because the licence plate has damage, and they didn't replace the licence plate.

I honestly hope nothing is wrong with the battery: but I should perhaps drop my conservative, and hypermiling driving style. Because only under heavy load, will the battery show if anything is wrong. I reported my findings anyway: up to the dealership if they wanna do something with it.

The point being: if the battery dies within the warranty period, then no matter if the factory warranty has expired. They will have to deal with it anyway, as I bought the warranty pack for more then € 500.

 

[Oostenrijker]

This is how the battery looks at 100% dash SoC.




This is how it looked the other day, when I drove the battery down to almost 12% Leafspy SoC: but not under full load, but only city driving.



And this was, when I purposely was driving like an German: I went on the Autobahn as well, and floored the pedal. But it went over 600mV voltage difference, before the car at 12.4% decided to activate Turtle Mode. My conclusion is, that with this high mileage leaf. I might only be able to go as low to 12% Leafspy SoC, because of the weaker cells.

I don't think I can go down to 5% Leafspy SoC. Dealership going to a battery test when I have the recall done, so I will drop it with an low as possible SoC. Around 14 or 15% Leafspy I guess.

But I have no high expectations: Nissan doesn't stand for it products, and the sale persons are stupid. If I argue that I can't use 12% of the remaining capacity, while they told me the battery pack was stil in a good state.

And also the capacity bars showing it: then I would argue, they sold me Leaf with an not so good battery pack anymore. It might have an 85% SoH, but not if I count in not being able to use 4kWh of reserve.

So if you ask me: it should already actually have lost a bar, if the SoH also took into account the weak cell's that show at the bottom SoC. Starting to show up at 17.9% Leafspy SoC.

 

[Astral]

My friend, I read most of your comments but you should be aware that you should use the battery in the 80-20% range as much as possible. What you are doing, driving to below 10% and to 0% is not good for the longevity of your batter. You should never go below 20ish%, and definitely not below 10%.

On the up side you should not charge to more than 80% as much as possible and only charge to 100% when you are about to go to a longer trip. Quick charging is also not advised, especially not more than 2 times on a longer trip since this will really heat up the battery a lot. When you quick charge try to do it in the 30-70% range if possible as that will give you the fastest charge and the lowest heat possible. If really needed then go for 20-80% also on quick charge. To go beyond this is much more time consuming and much more intense for the battery.

If you want any longevity from this already degraded battery, you need to treat it much nicer. And yes, most of the degradation comes with time and not with miles/kilometers you do. And this is if you treat it nicely. If you treat it poorly you will degrade it faster.

Such is the life of a Leaf owner. If you want to not think about the battery, get a Tesla or something with active battery management.
Good luck.

 

[Oostenrijker]

That might be all true and I agree with those statements: however the range of an degraded 40kWh is to small, to stay between 20% and 80% SoC. I actually tried it, and found out it's not doable.

So there are times I need to go below 20% and I can't go lower then 12% because, then the weak cells get a to hig difference in voltage. Which means I haven't even been below 10% SoC, as it's impossible with my Leaf....

Also the Leaf charges to slow with AC charging: only max 6kW, and only when I can find a 22kW public charger. Which means, after driving about 200km and staying somewhere for more than 5 hours. My battery still won't be full, because mostly it only charges with 3kW.

 

[Astral]

I am sorry but if this is the case, you got yourself a wrong car. Using it this way is only going to increase the degradation and longterm it will have the same outcome - you will get another car. So if I were you, if the range is not enough, at least trade up to a 62kw Leaf. Or get the Bolt which is eaqually as cheap if money is the issue, if not just go for a Model 3 or any other modern EV and you will have a much nicer time.

 

[Oostenrijker]

When I don't need the range, I generally only charge until 60% a 65% totally. But when I need the range, then I will use it. Life is to short, to put yourself so many limitations.

In the end I will probably just trade the car in for another EV: be it in a year or maybe 3 years? It's not worth to put so many limitations, on how you should use the car.

I did it with the Airco of my previous car, and it broke anyway..... so no, I won't baby it. And if it breaks within the first year of my ownership, then I got the warranty anyway.

 

[Astral]

Battery warranty will only cause you headaches, check other threads on that for more info. I agree with you that it's not good to have such limitations, but you are driving a Nissan Leaf. If you don't accept the limitations then in my opinion you should not drive this car. But of course you can do what you like and I wish you good luck and many happy kilometers.

 

[Oostenrijker]

As I said before: I tried staying within these limitations, but that gave me way more stress. Then every now and then going below 20% SoC. The thing being is, there aren't enough CHAdeMO chargers.

And also they are expensive.... for example I was only charging until 90% and afterwards, that got me into trouble. Because charging it on the destination is to slow, so I better charge to 100% whenever needed.

So if I need to drive 230km, then I can make it on a full charge: last time I had 30% left, and then I charge like an hour at 3kW, after which I went to the next destination. An Chinese restaurant, about 15km drive.

There I charge again, for like another 1.5 hour. Which wasn't enough to get home, and then I put the airco on. And in the end I got stranded with 13% SoC, because I couldn't make it to the fast charger. So another AC charging for an hour.....

All because I also try to avoid using fast charging: ofcourse if I did fast charging, at the second stop. Instead of AC charging, then I would have been able to drive in one go. But I try to avoid fast charging.

Currently I'm running a third party battery test: it's from an Austrian company. I'm going run it down as much as possible again: actually I don't care, if it does damage? I would rather go through the hassle, of getting this battery fixed/replaced. Then babying it, because it's only postponing things.

But I consider trading this Leaf in for an 62/59kWh Leaf: only I don't wanna do it yet, and perhaps the next EV might not even be an Leaf? I found that MG4 are also really interesting, but I purposefully wait with buying an next one. On this point, I would lose to much money....

 

[Astral]

What you described, you don't need to avoid fast charging, you need to avoid fast charging to 100%. You could have fast charged once 30-70% and then again 30-70%, no need to do AC on trips. Keeping the fast charge in 20-80% range will help keep the battery cool. You will actually do more damage going once from 20 to 100% then two times from 20 do 80%. Also speed increases battery temp, if you can drive not faster than 100-110 km/h that will also help.