Battery degradation in a used Nissan Leaf

DrEskimo

vampireechidna said:

My first Nissan Leaf was a 24Kwh with a realistic range of 90 miles in the summer and about 80 miles in the winter. I know from a previous family member who owned a 30Kwh they could get a realistic 120 miles in summer and about 110 miles in winter. Indeed it's how it's driven and battery care.

OK, so with you're own driving style and journey types, you know to expect 3.75mi/kWh (90miles/24kWh) in the summer and 3.3mi/kWh in the winter (80mi/24kWh). What other people get is largely irrelevant. I know people who have got 250miles from a single charge in my Zoe 41kWh....but they were crawling at 4mph in London traffic.....I rarely expect to see above 160miles.
The fact you were expecting a 33% increase in mileage with only a 25% increase in battery capacity when the car was in all other respects identical was a bit optimistic. 100 to 110 is what you should have been expecting.

vampireechidna said:

If the dealership offer to bring the battery up to say 95% capacity, inline with it's age and mileage, that would have been reasonable outcome. Alternatively an exchange for one that had a better capacity. My annoyance comes from the lack of resolution. It appears to be a case of, "Well it's normal and you should continue to drive it". At this stage I don't know how quickly the next bar will drop, losing further range. 

I agree with the suggestion on obtaining a more independent inspection of the battery state of health. Like most people who would buy one of these cars, I don't know if this kind of degradation is normal. From what I've seen and read, it appear it's not so normal. My question to the dealership was, is there a fault with the battery pack? again I get the answer  what I've experienced is normal behaviour. Yet not what what I was told when initially buying the car and parting with a lot money to do so.  Thanks to those that have responded, I appropriate the suggestions and time. 

We know that the battery drops a bar at 92%. So when you bought the car 6-weeks ago, the lowest it could be (notwithstanding gzooms comment of underhanded fiddling...) was 93%. You really expect a dealership to go through the entire process of battery refurbishment and exchange to gain just 2%? That would give you just 0.6kWh more, which in the summer translates to an additional 2.25miles in range....This is well within the margin of error from driving behaviour, wind direction, AC temp, etc etc.

I feel like you are placing undue importance on having a 'lost bar' rather than thinking more clearly about what it actually means. Had you no battery health indicator and asked for the SoH from the dealer before you bought it (something my dealer gave me from the service report) you would have seen 93%, probably suggested that was OK and been none of the wiser about the small drop of 1-2% in SoH in the last 6-weeks.

Herzlos

vampireechidna said:

The battery gave full 12 bars suggesting good health for the first six weeks.

I think that's the crux of it and why you are stuck - when it was sold, the battery appeared to be healthy and there's nothing the dealer could do. It sucks that it dropped in the 6 weeks of ownership but it's hard to prove if it's just wear or if something happened.

Whilst not helpful, it's worth getting a proper diagnostic done *before* buying the car. Hopefully the range is sufficient for you, since you had a 24kwh Leaf previously. If it drops under 80%, Nissan will replace it.

If it's a deal breaker for you, can you see if a batter specialist can replace the bad cells?

DoaM

Whilst your posts are readable, you can offset the impact of dyslexia by slowing down and re-reading what you've posted prior to hitting Post Comment. (That's what <name deleted as I haven't asked them if I can say about their disability, although they've mentioned it themself previously> in the Parking board does, I believe). This isn't Instant Messaging where fast typing and instant responses are required.

AdrianC

Herzlos said:
If it drops under 80%, Nissan will replace it.

A lot lower than that... Nissan say "less than 9 bars" - so 8 bars out of 12. 66.7%, nominal.

DrEskimo

AdrianC said:

Herzlos said:
If it drops under 80%, Nissan will replace it.

A lot lower than that... Nissan say "less than 9 bars" - so 8 bars out of 12. 66.7%, nominal.

 Yea that's the same as my Zoe. 8yrs/100k miles with replacement if it drops below 66%.

The good news for the OP is that 30kWh packs appear to be in short supply, so if they did reach below 66% in the warranty period, they might get a 40kWh battery replacement....sweetsand said:

Great posts DrE
We have thought about an eltric car in a couple of years time when batteries get even better but weary about them
not doing what the maker suggests well not for long.
Would you recoomed the OP gets an independt report once they have given the dealer a chance as I suggested but the OP needs to know what they need from the report that will have an impact on the dealer, a positive one.
Thanks

It's only the Leaf's that have the reputation for large degradation due largely to the lack of active cooling. Admittedly mine has only just ticked over 10,000 miles, but at 3.5years old my battery is still sitting at 98%.

No need for an independent report. Any dealer can scan the car quickly and give you the state of health. I even bought a cheap OBD dongle off Amazon and that can give you all the information you need.

@vampireechidna have you checked to see whether it might need a BMS update? I know the 22kWh Zoe's had an issue where it would report a much lower SoH than reality, and after a BMS update it would give a more realistic range and battery health status.

vampireechidna

gzoom said:

vampireechidna said:
lMy question to the dealership was, is there a fault with the battery pack? 

You're not the first to experience this. I've seen similar reports of people buying a Leaf from a Nissan dealer with 12 bars only to find within a few hundred miles the actual range/battery state is far worse.

Nissan dealers have access to a 'reset' tool which I believe essentially wipes the BMS memory, and makes the BMS think its brand new, by default the brand new range/battery state is than reported. But clearly with a degraded battery after a few charge cycles the BMS will recalibrate to the ture battery status.

Am not saying this is what your dealer did, but car dealers are car dealers....

Only over the past few days have I now become aware of this BMS resting. It's very possible they could have done this, however I cannot accuse without evidence. What I do think is a good idea, is to contact the previous owner. I'm fortunate that the person who part exchanged this vehicle lives in my town. If they wish to provide me the information of the bars, then that would give me some indication of this very much happening. Say they part exchanged on 11 bars. It's a long shot, might be worth a try. 

Herzlos

gzoom said:

vampireechidna said:
lMy question to the dealership was, is there a fault with the battery pack? 

You're not the first to experience this. I've seen similar reports of people buying a Leaf from a Nissan dealer with 12 bars only to find within a few hundred miles the actual range/battery state is far worse.

Nissan dealers have access to a 'reset' tool which I believe essentially wipes the BMS memory, and makes the BMS think its brand new, by default the brand new range/battery state is than reported. But clearly with a degraded battery after a few charge cycles the BMS will recalibrate to the ture battery status.

Am not saying this is what your dealer did, but car dealers are car dealers....

Is there any way to prove it? Such as the car reporting that the battery is only a few weeks old when it obviously isn't?

DrEskimo

vampireechidna said:

gzoom said:

vampireechidna said:
lMy question to the dealership was, is there a fault with the battery pack? 

You're not the first to experience this. I've seen similar reports of people buying a Leaf from a Nissan dealer with 12 bars only to find within a few hundred miles the actual range/battery state is far worse.

Nissan dealers have access to a 'reset' tool which I believe essentially wipes the BMS memory, and makes the BMS think its brand new, by default the brand new range/battery state is than reported. But clearly with a degraded battery after a few charge cycles the BMS will recalibrate to the ture battery status.

Am not saying this is what your dealer did, but car dealers are car dealers....

Only over the past few days have I now become aware of this BMS resting. It's very possible they could have done this, however I cannot accuse without evidence. What I do think is a good idea, is to contact the previous owner. I'm fortunate that the person who part exchanged this vehicle lives in my town. If they wish to provide me the information of the bars, then that would give me some indication of this very much happening. Say they part exchanged on 11 bars. It's a long shot, might be worth a try. 

When were the services done? Did it have one from the dealer before you bought it?

I'm sure if you ring up a different dealer and give the reg then can look at the servicing reports and tell you what the SoH was at each date?

vampireechidna

AdrianC said:

vampireechidna said:

At this moment in time it's not a requirement by law to state the battery capacity of a used EV. Going forward I think they should. 

Even if it was a legal requirement, you said...

The battery gave full 12 bars suggesting good health for the first six weeks.

So what would they have said? "The battery shows full strength, 12 bars"

In your ownership, it's dipped to 11 bars - 11/12 = 91.7% - after 3yrs from new.
The Nissan warranty replaces it if it drops to 8 bars - 8/12 = 66.7% - after 8yrs.
Assuming that's a linear curve, you will not reach 66.7% by 8yrs. You'll reach about 75% (9/12?) when the warranty expires. And, AIUI, there's some evidence that initial degradation can be steeper than later, so it's more likely to be around 85% after 8yrs.

Everybody who's ever owned a laptop or mobile knows that LiIon batteries lose capacity over time. We just don't normally keep the same laptop or phone for 8yrs. EV batteries are the same basic chemistry as laptops or mobiles.

Laptops and Cell phones are not the same price as a used vehicle. People pay a lot more money for them. Yes I believe to make a more informed choice, they should state the current battery health, for example 93.2%. That way the customer can choose to buy that vehicle or another. Imagine not being able to see the millage? I understand fully the Nissan warranty terms, having had them given to me by the dealership.  Not all vehicles will have the same level of degradation, it does depend on it's past treatment.  

vampireechidna

DrEskimo said:

AdrianC said:

Herzlos said:
If it drops under 80%, Nissan will replace it.

A lot lower than that... Nissan say "less than 9 bars" - so 8 bars out of 12. 66.7%, nominal.

 Yea that's the same as my Zoe. 8yrs/100k miles with replacement if it drops below 66%.

The good news for the OP is that 30kWh packs appear to be in short supply, so if they did reach below 66% in the warranty period, they might get a 40kWh battery replacement....sweetsand said:

Great posts DrE
We have thought about an eltric car in a couple of years time when batteries get even better but weary about them
not doing what the maker suggests well not for long.
Would you recoomed the OP gets an independt report once they have given the dealer a chance as I suggested but the OP needs to know what they need from the report that will have an impact on the dealer, a positive one.
Thanks

It's only the Leaf's that have the reputation for large degradation due largely to the lack of active cooling. Admittedly mine has only just ticked over 10,000 miles, but at 3.5years old my battery is still sitting at 98%.

No need for an independent report. Any dealer can scan the car quickly and give you the state of health. I even bought a cheap OBD dongle off Amazon and that can give you all the information you need.

@vampireechidna have you checked to see whether it might need a BMS update? I know the 22kWh Zoe's had an issue where it would report a much lower SoH than reality, and after a BMS update it would give a more realistic range and battery health status.

I was aware there is a BMS update for the 30kwh Leaf's. The dealership has told me, all updates have been done. 
The only way to conclude if this hasn't been applied, is if the state of health doesn't match the number of bars illuminated or the range is better than the expected  for the state of health. I have now invested in the kit for LeafSpy, to look at the battery health. The dealership told me the loss was 6%, however that would suggest the 12th bar is lost at around 94%. My 24kwh Leaf dropped at 90.2 % (Had that verified before I sold the vehicle)