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I'd love to borrow the collective knowledge of the crowd here, when I bought my leaf in Feb (65 plate, 24kw, with 51k, 1797 L1/2 charges, 2 QC's). SOH was consistently 92.6%, which I felt was exceptional. So I purchased the car, and have been very happy. I regularly QC for 10/15 mins here and there. Never toward the top end or from empty. Usually just to extend a 65 mile round trip to my parent with some comfort.

March, Apr, May the SOH was 92.1, 91.8, 91.7. So it was pretty consistent reduction, inline with the charges and use. Then last month, as the car had not really been used since march the SOH dropped to 83.8, a huge fall for only 73 miles of use. Over the period of no use, i never bothered charging it at all, as it was bout 65% charged, and over the next month of just running 2 miles to the shops and back, ran it down to 22%, then charged it to 80.

Making sure it was never left empty or full for long periods, I was super surprised to see a drop of 6% SOH in just 2 weeks. It has remained steady ever since. Has there been any reports of lack of use during lock-down resulting in huge drops in SOH?

133416


Any anecdotal information is appreciated*

*sorry if this has been covered and I missed it!
 

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Try running it down to about 20% charge and then giving it a full 100% charge (until it completely stops charging) and see if it goes up a bit.

I've had my 30kWh for less than two weeks and after predominately charging it to only around 80% it gradually dropped about 0.2% a day from 92.4% down to about 91%. After doing a couple of 100% charges it is climbing back up and is now at 91.8% - 0.8% higher than it was just 3 days ago...

In reality the battery is not getting better or worse over such a short time, it is only what the BMS is reporting it is. It looks like the BMS has an algorithm that gradually ticks the SoH down over time if it can't measure it, which it can't do unless you charge to near 100% and use the battery over a reasonable range of charge periodically.

So if the car goes for a long time with little use and not going near 100% charge perhaps the SoH figure has ticked down over that time. If the battery was around 65% SoC for most of that time I can't imagine there would be any real degradation over that time, and all your cells look balanced so it's not going to be a faulty cell.

I'd try using the battery over a wider range and giving it a few full charges and see what happens. I don't think the BMS in the Leaf is particularly clever...
 

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BTW just noticed your car is reporting 48.6% SoC with cell voltages of over 4 volts. That isn't right at all. 4 volts should be around 80% SoC, and 100% SoC is around 4.12 volts.

Looks like the BMS has somehow lost track of the true SoC of the battery over the time the car has sat idle. You may need to run it down to the low battery warning and charge it back up to 100% a few times and see if it re-learns the capacity and SoC correctly.

Just checked a couple of my Leafspy screenshots and mine indicates 69.2% SoC at a lower cell voltage of 3.93 volts and 77% SoC at 3.98 volts. This is about what I would expect.
 

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Try running it down to about 20% charge and then giving it a full 100% charge (until it completely stops charging) and see if it goes up a bit.

I've had my 30kWh for less than two weeks and after predominately charging it to only around 80% it gradually dropped about 0.2% a day from 92.4% down to about 91%. After doing a couple of 100% charges it is climbing back up and is now at 91.8% - 0.8% higher than it was just 3 days ago...

In reality the battery is not getting better or worse over such a short time, it is only what the BMS is reporting it is. It looks like the BMS has an algorithm that gradually ticks the SoH down over time if it can't measure it, which it can't do unless you charge to near 100% and use the battery over a reasonable range of charge periodically.

So if the car goes for a long time with little use and not going near 100% charge perhaps the SoH figure has ticked down over that time. If the battery was around 65% for most of that time I can't imagine there would be any real degradation over that time, and all your cells look balanced so it's not going to be a faulty cell.

I'd try using the battery over a wider range and giving it a few full charges and see what happens. I don't think the BMS in the Leaf is particularly clever...
That's great feedback, thank you. I never realised it would continue to click down regardless. But as you say, one it can take some good measurements the number may change.
 

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That's great feedback, thank you. I never realised it would continue to click down regardless. But as you say, one it can take some good measurements the number may change.
This sounds messed up. I'd go as low as possible and then for charge it. It that means driving around the neighborhood until you get turtle mode so be it

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