Thursday, February 6, 2020

January 2020 Drive Report; The Adjustment!

In keeping with my policy of mostly DC charging only and to no more than 80%, I felt this was my best bet for long term battery health.  Yes, when my NCTC runs out mid month, so there will be less DCing and more home charging.   Now, I did get a bit of a reprieve when Nissan added a $250 perk from EVGO for any new LEAF purchases starting November 1st.   Now, I can't help  but feel personally responsible for bringing this tidbit of good news to the EV community as I picked up my E Plus November 16th and the promotion was announced a week later and retro'd back to November 1st so I would be included despite actually getting my LEAF before the promotion was available.  No Thank yous needed, I get my thanks from seeing another converted EVer!

So my GREAT battery stats thru the first 3,000 miles were not a surprise. I had lost a mere few 10th of one percent on both the ahr and SOH fronts and all was golden.  So I did not hesitate when I heard there was a HUGE storm that would cover the entire Western Olympic Peninsula which sounded like a chance for a great road trip challenge of driving the Highway 101 loop where no DC chargers exist.  So I plugged my E Plus in to my home EVSE for the first time, charged to 98%.  This was the first time over 82% (done on the Volta level 2 while at Star Wars...) since bringing the car home, then took off.  It was a fun trip albeit a rather wet one.  I did DC 3 times (once in town at the end of the trip to check on Rapidgate effects) plus a handful of short level 2 stints. IOW, nothing major or unusual.

The next day was errand day so bunch of short in town trips. I had enough range to cover it w/o charging and thought nothing of it.  Then Saturday came, 2 days after my Highway 101 trip, and it happened.

The Adjustment

As we know, starting in 2018, the LEAF pack stopped doing its random ups and downs loosely based on the distance drove and fast charges collected.  The stats actually never went up.  It was just a slow steady drop. Some days, no drop as much as 3,4,5 days.  Or a drop of .01- .02% here and there.  Nothing major.  But then, every 90 days a big drop as much as one percent or more. This went on like clockwork for 12 to 18 months all over the World and then all but stopped. In fact on my LEAF; month 15 my stats went UP! First time the numbers went up at all. Before not even a single .01% increase.  But that also signaled the start of a degradation rate that dropped even lower than the 89 days between adjustments.

So I went from expecting an SOH under 90% before the 4th of July to thinking I would be at 92 something % forever!  As we know, I traded up for the E Plus in Nov (which means two more adjustments that never happened) with SOH still around 92.23% or something having lost .08% the previous 6 weeks.

The Expectation

Now a few early E Plussers including ones who had the 40 kwh like me stated that they didn't see the adjustments and.... well, I should have known better since they were all in the 97's and 98's% SOH and I was still over 99½%.  Guessing with all that range, they simply didn't care and I don't blame them.  Either way, I felt that since I lost 7% in 1¾ years on the 40 kwh, the bigger E Plus would lose less because it was a bigger pack. I didn't expect my driving to change much so the average 16,000 miles a year wouldn't change. So I was looking at 4-5% initial drop then settling into a much slower degradation pattern.


That Saturday,  I lost .68% dropping to 98.97% SOH and thought..."Well, Ok, I guess I knew this was coming.  But then I lost .18% the next day, .21% the next day and .74% the next!  I thought it would never stop!  Finally, it settled on 96.97%.  In one week, I went from having the highest SOH of any E Plusser to having the next to lowest.  (The only one lower than me has over 50,000 miles on his car and he is just "barely" below me)

The Numbers

Miles driven;  1329.3
DC received; 292.909 kwh
AC received; 31.166 kwh
Home Charging; 27 kwh
Public fees; $1.63
Home fees;  $2.28  (8.44 cents per kwh)

The Plan

Before anyone thinks that my process didn't work, I have to interject by saying all EVs experience a large capacity (as in ~4-7% more or less) drop initially then they settle down.  Granted, earlier LEAFs had undersized batteries which greatly hampered their ability to hold up. This along with Nissan instrumentation; created range anxiety and charging to a higher SOC than was likely needed. This obviously made it worse.

Other than less DC charging day to day, I won't be changing any charging habits.  I will still keep it no more than 60-70% most of the time only charging higher for longer excursions.  I know I had said this many times but too many people who charge to 100% and haven't lost a bar are on Facebook and other social media sites saying it doesn't matter and that is simply wrong.  It does matter. How much it matters all depends on what you plan to do with the car but for maximum longevity, its best to keep the pack around 50%.   Oh course, this won't be possible but you get the idea.  So yeah 80-20% is good but 70-30% is better.

For validation, one need look no farther than their phone. Battery management apps abound and all are chalked full of advice. Many will even give you predictions of screen time and battery longevity based on your actual usage history (Hopefully doing a better job than Nissan did on the GOM...)

So if you are the "plug it in and forget" type, then skip this sec... Oh too late, you already read most of it.  But if you want to stretch that battery (and keep the phone a bit longer)  here is a couple pix to digest. This is my phone's battery app.  (Notice where my SOC is?  With a wireless charging pad, its easy to do multiple charging sessions without worrying about wearing out the charging port)

So how inconvenient is charging to 60%? Well, its not.  Obviously the public charging thing can be inconvenient especially if you are doing nothing but watching the station run but I do have things to do which is mostly wants and rarely needs but it takes up all my time at the station.  Although I get 30 mins of charging free at EVgo, I frequently unplug at 20 mins give or take when I don't feel like waiting the extra 10 minutes which is the norm.

But soon, it will be nearly all home charging which means no real compromise. As far as making 60% work? I will find a way!

Finally for those who think my degradation rate will continue at the "current" pace, my extrapolated SOH @ 100,000 miles based on my current mileage and loss would be... 16.26%.


  1. Interesting food for thought as always David, sounds like Nissan need not worry too much about a the likelihood of you costing them a warranty claim.

    I hear/read so much criticism of Nissan and its choice to not include active battery temperature management and it probably would slow some battery degradation, especially for those exposed regularly to hot temperatures, but I do not have a sense that they are having to replace very many batteries for folks with 2015 and newer Leafs and for the other manufacturers, they should be able to offer superior warranty coverage and yet I see no evidence of that happening. Hmmm

    1. The rate of battery replacement has plummeted as expected. Technology has simply moved forward. Does this mean Nissan is doing a good job? I say no. They are definitely improving and the car is more "buyable" but due to other tech added along with "enough battery to burn" I expect to have over 200 miles of range when I get rid of the car in 5-7 years. I won't keep it longer than that. Automotive technology is moving faster now than any point in my life so I will be upgrading.

  2. My Leaf+ SL has 94.59 SOH @ 14,968 miles. I haven't been tracking it at all. Hopefully this means I've finished the 4-7% initial drop and will now level off. I usually charge to 70% very rarely above 92%. Hottest battery temp Leaf Spy showed last summer was 109F.
    Thanks for your blog.

    1. What is your build date? As mentioned; my 40 kwh pack stopped adjusting after 15 months. Well 18 months if you count the one increase. Granted I only had it 21 months but still past the point of the 21 month adjustment (which lagged ownership by just over two weeks)

      Either way, you would be the lowest E Plus car so far. What is your location?

    2. I live in Albuquerque. Sequential #8647 Build date Jan 2019.

  3. More on battery management here

    1. Chart #3 illustrates my point PERFECTLY. Even at near optimum temps of 25º, the degradation rate at 100% SOC is 5X greater than 40% SOC. Now, realize this is not charging to 40% SOC. This can also mean (in my case) charging to 60-70% SOC and recharging at 20-30% SOC which means the pack spends a lot of time "around" the target SOC.

      This is a sliding scale where 90% is better but 80% is better than 90% and so on. IOW, the ONLY rule you need to follow is not charging beyond what you actually need.

      In my case as it would be for many others; I have way more range than I need 95% of the time so "living in the middle" is the 2nd rule. That is why I charge to 60%. FYI; I will add a pix which I should have done initially anyway but it shows the GOM estimate of 150 miles @ 61% SOC.

  4. My plan is to murder my 62 kWh battery and have Nissan replace it on warranty. I DC fast charge 90% of the time. Current status:

    92.33 SOH @ 8,5648 miles

    1. Hmmm... That could be a tough challenge unless you live in Phoenix or something. Let me know how it goes

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