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Sudden fall in SoH

6K views 16 replies 8 participants last post by  GOSPORT DAVE 
#1 ·
I got my new 40kWh Leaf at the beginning of March when it had 12 miles on the clock, SoH of 99.24% AHR 114.56 and Hx of 97.66%. (Although the car was brand new I found out it was built in August 2019.)

Up until Saturday it had covered 920 miles and the SoH had progressively dropped by about 0.02% per week to 99.03%, AHr 114.32 and Hx was up to 105.24%.

Today (Monday) at 3pm I went to the car and saw the SoH had suddenly dropped to 98.60%, AHr 113.82 and Hx up to 105.24. I have heard that on the 40kwh (unlike the 30 I had previously owned) SoH only goes down and can drop suddenly so while I knew it would fall at some stage it was a bit of a shock to see how much.

I then went for a 14.3 mile drive and when I got back the SoH was down to 98.53% and AHr had also fallen to 113.72 and the Hx had dropped to 105.21%. (First time I have come across an Hx drop on a 40). I had been expecting after the big drop it would settle down to small drops.

I have just been out to the car again (8.30pm) and SoH is now down to 98.46%, AHr 113.66 and HX is still at 105.21%.

Has any one else experienced the continuing fall like this in SoH and AHr after the periodic big step?

Meanwhile I am seeing exceptionally low energy consumption. The dash display today showed 5.2 kwh but Leafspy showed a consumption of just 2kwh over 14.3 miles and 26 Gids used. (The journey was out and back on the same roads so not in any way distorted by gradient.) At that rate the range would be about 275 miles.

Something funny is going on with the data LeafSpy is showing methinks.
 
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#2 ·
The reason the car doesn't show this number is that it's not some precise measure of the battery pack's state on a molecular level, it's an approximation using a number of indicators.

In other words I wouldn't worry about it unless it keeps falling fast and you start to lose range. Nissan won't do anything based on it anyway so there isn't much the can do.
 
#8 ·
I have compression checked a few cars over the years but it isn’t as easy as looking at an app on a phone. I would have been worried though if I had been losing compression at a rate of 1.5% per 1000 miles.

This is my third Leaf and I expect SoH to go down over time so not worrying as a such; more curious. I was anticipating a big step but was more interested in the fact that it was continuing to drop at 0.1% every few hours (another 0.1% disappeared today) and wondered if any one else had seen this patter.

I also check my ISA and my SIPP daily as again it is only a couple of clicks on a screen. I don’t do that because I am worried my money is disappearing but because I like numbers.


I hope I don’t offend anyone by saying this but people do post questions because they have an enquiring mind and hope for some technical comment (thanks to those who have given that) rather than a patronising dismissal.

I will now get back to worrying that I appear to only have a 275 mile range 😀
 
#6 ·
I had my 40Kwh LEAF for 2 years and covered 24K miles before PX for a 62Kwh Leaf..

Took delivery on 21-03-2018 - didn't get LEAFSPY until Aug 2018 so can only assume that the Battery SOH was 99.5% when new
21-08- 2018 - SOH = 97.23% at 5.5K miles
31-12- 2018 - SOH = 96.37% at 10K miles
21-03- 2019 - SOH = 95.96% at 12K miles
27-08- 2019 - SOH = 94.26% at 17K miles
31-12- 2019 - SOH = 93.96% at 21K miles
10-03- 2020 - SOH = 93.57% at 24K miles
After 24 months the Battery SOH seemed to Plateau out

I would charge to 100% and check what battery capacity remained as this determines what the winter range is.

After 2 years and 24K mile the Battery capacity remaining on an 100% charge was 35.5Kwh so lost 2 Kwh's or about 8 miles of range.

No point is being obsessive and continuing to check the SOH (ignorance is bliss) it only causes anxiety just relax, accept that the battery will loose capacity and enjoy the car. - Worst case scenario when the Battery is 8 years old it could have lost 30% capacity so just keep that in mind with regards to future usage.
 
#7 ·
it’s just this geeky group on mynissanleaf.com that tried to guess as to what is driving the algorithm at the 90 intervals. Some have even seen their SOH go up after the interval (in second year), which makes us think it is managing SOH against a schedule and the behind the scenes actual capacity.
 
#11 ·
For those of us who enjoy statistics I have set out the movement in SoH, AHr and Hx since acquiring the car. (For those who think LeafSpy should be ignored please ignore this post). This may also be of interest to others who have recently taken delivery of new cars
130506
 
#15 ·
That absolutely spot on, that will give you a reliable 160 miles summer range, expect the battery to loose 1 KWh of range per year. My 40Kwh had 35.5Kwh remaining on a 100% charge, after 2 years and 24K miles.

In comparison, the battery degradation on my 62KWh has been so far, horrendous, after 2 months and 1K miles, it has lost 2Kwh’s of range and 4% in SOH.
 
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