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I did not say there was a trickle charge.
You might not have said so but what you said implied that. Li-ion isn't designed with continuous self discharge in mind. Can't read your post any other way.


Trickle charging means charging a fully charged battery at a rate equal to its self-discharge rate, thus enabling the battery to remain at its fully charged level;

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

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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.
Are you implying that user is sitting in car at 100% draining traction battery?

Every morning my car even when plugged in after preheat shows car at 98-99% and never charging even though it should and could add a bit of juice. Must be faulty

- Leaf 30 kWh
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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?
SoH is such an inaccurate statement of of battery condition, it really provides no little more guidance than the capacity bar display.

Unless you plan on replacing the pack (or the car) in the next few years, I'd suggest you focus your search on LEAFs with lower miles (and/or a known history of efficient use, easy on the charge/discharge cycles) and 10 or more capacity bars.

The incremental cost will probably be worth it, given your relatively high-mile daily requirements
 

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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.
No EV does this. The final phase of charging is constant voltage mode so by the time the battery reaches 100% the charge current has tapered to an extremely low level. Typically tapering to less than 1/10th of the charge rate is used as the threshold to stop charging, (so about 600 watts here) once it reaches this it stops charging and doesn't charge again.

Even if it were to start charging again if it had dropped to say 98%, at that high SoC and cell voltage it would not be able to charge at more than that dictated in the constant voltage phase so well under 6kW, probably barely 1kW.
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.
There's absolutely no reason why charging at 6kW would be harmful vs 3kW per se, as 6kW is still only a 0.25C charge rate, which is nothing. Anything up to about 1C is considered a "slow" and easy charge for a Lithium Ion battery with no lifetime penalties.

If there is a correlation (and I'm not convinced there is) the only possibility would be the increased temperature rise of the faster charge rate. So if you did a long trip on the motorway that got the cells fairly hot, say 40C, and then plugged it in to charge as soon as you got home, 3kW charging may cause an additional temperature rise of say 3C to peak at 43C while the 6kW charge rate might cause a temperature rise peaking at 6C resulting in the cells going to 46C for a while.

Once you go past a certain temperature (approx 40C) every few extra degrees causes quite a bit of additional degradation. So in a driving cycle where the car arrives home frequently with a fairly hot battery and then is put immediately on charge I could see some temperature related additional degradation on the model with faster charging. However you can thank Nissan for that by not adding any active thermal management - it's not the higher C rate that's harmful its the higher temperature that results when there is no cooling system.

In that situation I would probably advise setting a charge timer so that the battery has several hours rest after coming home before starting charging. (Or buy a car with active thermal management for the battery then the problem wouldn't exist!)
 

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£7,000, 2014 Acenta model, 63k miles 24kWh battery with a 6KW charger.

Bit late to the party but I have same model, year, mileage etc and paid similar but with a SoH of 96%, only 8 rapid charges & over a 1,000 slow charges <- LeafSpy tells you that too!

AFAIK constantly rapid charging degrades the battery the most. Fortunately for me the previous owner only ever home charged, had a 50 commute, slow charged in the work day then drove home and slow charged overnight, essentially exercising the battery 20-80% on a daily basis.
 
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