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Hi,


First time EV buyer here, looking for a second hand leaf for my wife who has a 40-45mile commute each day. We've found a car locally to us in the UK, for £7,000, 2014 Acenta model, 63k miles 24kWh battery with a 6KW charger. I've been doing some reading up on what to look for avoid in the leaf, and have used Leaf Spy to interrogate the battery/DTC codes. I can see it has a a 69.8% healthy battery, but having only had leaf spy for an hour I'm still trying to make sense of it all. The battery had a 92% SoC, and Leaf Spy reported a 53 mile range, and it was quite a cold evening so I reckon it would do her commute, but maybe not very comfortably.

Basically if anyone with a bit more 'leaf spy' knowledge can tell me if this is a good buy or not it would be really appreciated. I have first refusal on the car until noon tomorrow, and I'm in two minds about it.


Flikr album with all the screenshots:
 

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SoH 69.8% on 24kWh Leaf. Walk away. I wouldn't. You'll barely make it every day especially in winter.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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7k! For 55 miles off range.
Who says evs depricate badly.
 

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Discussion Starter #6
Thanks for the quick replies ;)

I think I've gotten some of the leaf spy info confused, in some of the screenshots that show all the cells, the SoH is 73.5%. It's the GIDs on the main screen that show 69.8%. Make any difference. Also, what's all the red about on the page that shows individual cell voltages?
 

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Thanks for the quick replies ;)

I think I've gotten some of the leaf spy info confused, in some of the screenshots that show all the cells, the SoH is 73.5%. It's the GIDs on the main screen that show 69.8%. Make any difference. Also, what's all the red about on the page that shows individual cell voltages?
LeafSpy should hold the data off last session post it here.

Nope 73.5% isn't much better either. Might give you a couple of additional miles but this isn't worth the money.

Would you consider driving at max 50 without any heating?

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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You don't tell us anything about her commute journey, road types, speeds, traffic density, altitudes/gradients, nor her driving style, or whether there'll be charging facilities at home and work.
But car's quoted headline 24kWh is a gross capacity, really just 22kWh usable WHEN BRAND NEW.
73.5% of 22 is a mere 16.17kWh, that ain't much at all.
It's a NO from me, I'm out.
Is this a main dealer, independent dealer, used-only place, or private sale? At £7,000 you'll be getting a car that will cause both of you a lot of stress, don't buy it, waste of money!
 

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Agree, run away from this one. The clue is the 6kW charger. It is known that the 6 kW charger causes faster battery decay than the standard 3.3 kW. I had personal experience of losing 13% of LEAF (24 kWh) battery capacity in 14k miles with a 6.6 kW charger. Look for a car with the standard 3.3 kW charger and I would expect the battery to be in better shape.
 

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Agree, run away from this one. The clue is the 6kW charger. It is known that the 6 kW charger causes faster battery decay than the standard 3.3 kW. I had personal experience of losing 13% of LEAF (24 kWh) battery capacity in 14k miles with a 6.6 kW charger. Look for a car with the standard 3.3 kW charger and I would expect the battery to be in better shape.
If love to know how you arrived at this conclusion. If you know the C rating of Li-ion cell AESC use then sure.

Leaf Pack is 80Ahr when new so pack C rating is 80A.
Since packs is 2P, each cell has 40A C rating.

3.3kW really pushes 8.25A to the pack. That's 4.125A per cell.
That's just over 0.11C.
6.6kW would be 0.22C.

Compare this to rapid that used 100A. That's 1.25C and that warms the battery up.

Additional heat generated isn't substantial.
You are likely to generate more heat by actually using the car.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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That car is close to fully valued without the battery issue, so you can find another if you look.
Well done on doing your due diligence with LeafSpy. It says run away or accept a hefty bill to repair the battery. Don't let your heart rule. :unsure:
The interesting screen on LeafSpy is the one with the red bars which shows the difference between the battery modules in mV. It should be around 10-15, maybe 20. I would expect that you have one or more cell that has a significantly lower reading causing the rest to be pulled down by the battery balancing. The module containing that cell will need to be replaced which involves dropping the battery pack and digging around inside it. This is specialist work, most Nissan dealers cannot do it although some specialists such as Indra can do it cheaper. Expect to spend at least £1k and possibly a lot more if the modules are at the bottom of the stack. An offer of £2k less would be sensible if you want to take the risk and organise the work, but even then the other modules may be damaged.
 

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If love to know how you arrived at this conclusion. If you know the C rating of Li-ion cell AESC use then sure.

Leaf Pack is 80Ahr when new so pack C rating is 80A.
Since packs is 2P, each cell has 40A C rating.

3.3kW really pushes 8.25A to the pack. That's 4.125A per cell.
That's just over 0.11C.
6.6kW would be 0.22C.

Compare this to rapid that used 100A. That's 1.25C and that warms the battery up.

Additional heat generated isn't substantial.
You are likely to generate more heat by actually using the car.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
When I sold my 24 kWh LEAF into the trade to a specialist EV dealer, he told me that. This was back n 2018 that he was finding that the 24 kWh LEAFs with 6.6 kW chargers were showing more battery capacity loss than standard 3.3 kW ones. I guess the jury is out on that one but it was the reported experience of a trustworthy EV dealer who had had a large number of 2nd hand LEAFs through his hands.

It is not heat alone that will cause problems but how the electrodes expand and contract as they charge or discharge. There are something like 43 different ways (and counting) a Lithium Ion battery can decay. And most of them beyond the top three are not at all well understood,. Compounded by the use of secret sauce additives by each of the manufacturers so one across brands is not comparing like with like.
 

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When I sold my 24 kWh LEAF into the trade to a specialist EV dealer, he told me that. This was back n 2018 that he was finding that the 24 kWh LEAFs with 6.6 kW chargers were showing more battery capacity loss than standard 3.3 kW ones. I guess the jury is out on that one but it was the reported experience of a trustworthy EV dealer who had had a large number of 2nd hand LEAFs through his hands.

It is not heat alone that will cause problems but how the electrodes expand and contract as they charge or discharge. There are something like 43 different ways (and counting) a Lithium Ion battery can decay. And most of them beyond the top three are not at all well understood,. Compounded by the use of secret sauce additives by each of the manufacturers so one across brands is not comparing like with like.
So you were selling your 24kWh Leaf to a dealer who told you this. Would I be right in thinking yours had the 6.6 charger?
 
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So you were selling your 24kWh Leaf to a dealer who told you this. Would I be right in thinking yours had the 6.6 charger?
Typical cynical response - you took the bait. :)

Yes is the answer, but you would be wrong to think it had any influence on the price achieved, because it was a conversation post deal when money had already changed hands.

Ask Ghosn, if you can, why Nissan really sold the Sunderland battery factory. I think they might know that their batteries may not be as robust as others and it may not just be down to the lack of active cooling.

I would like to know if the battery balancing phase of a 6.6 kW charger runs with higher currents than a 3.3 kW since the cells would be more vulnerable when close to maximum permitted voltage at the end of a recharge to 100%.
 

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Typical cynical response - you took the bait. :)

Yes is the answer, but you would be wrong to think it had any influence on the price achieved, because it was a conversation post deal when money had already changed hands.

Ask Ghosn, if you can, why Nissan really sold the Sunderland battery factory. I think they might know that their batteries may not be as robust as others and it may not just be down to the lack of active cooling.

I would like to know if the battery balancing phase of a 6.6 kW charger runs with higher currents than a 3.3 kW since the cells would be more vulnerable when close to maximum permitted voltage at the end of a recharge to 100%.
Look Nissan are shite at batteries. Gen 1 batteries were bad. Gen 2 batteries aka lizard chemistry aren't any better. They blamed BMS software but programmers fixing this reminds me of programmers fixing VW emissions

Leaf battery has bigger issue heat than charging. I hope you never consciously drive with more than 2 bubbles on throttle or regen cause that would have exceeded 7k.

US consumers who use EVSE there by on L1 charging should have the best battery health? As they'd be doing 0.05C charging?

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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I think Mr G is onto something. Imagine someone leaving their leaf on the 7kw charger. Once fully charged, the batteries will get a short boost at 7kw every time the voltage drops slightly. I can't see this is going to do a cell any good.

Regarding the point about driving charging & discharging at a much higher rate than charging, that is correct. However, I would rather have 90% of charging at a slow rate, and just 10% at an unavoidably high rate.
 

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I think Mr G is onto something. Imagine someone leaving their leaf on the 7kw charger. Once fully charged, the batteries will get a short boost at 7kw every time the voltage drops slightly. I can't see this is going to do a cell any good.

Regarding the point about driving charging & discharging at a much higher rate than charging, that is correct. However, I would rather have 90% of charging at a slow rate, and just 10% at an unavoidably high rate.
Just shows you know nothing about Li-ion charging.
Leaf cells are charged at 4.1v.
Li-ion charging is constant current followed by constant voltage.

The charger will keep current constant until cells hit 4.1v at this point the charger switches to constant voltage until amperage drops to a certain level.
The BMS tends to kick in at same time as CV.

There is no trickle charge like lead acid batteries. Once charged, the charger disconnects the pack.


- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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Just shows you know nothing about Li-ion charging.
Leaf cells are charged at 4.1v.
Li-ion charging is constant current followed by constant voltage.

The charger will keep current constant until cells hit 4.1v at this point the charger switches to constant voltage until amperage drops to a certain level.
The BMS tends to kick in at same time as CV.

There is no trickle charge like lead acid batteries. Once charged, the charger disconnects the pack.


- Leaf 30 kWh
Sent from mobile phone so please mind the typos
I did not say there was a trickle charge.
 
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