Sunday, May 1, 2016

April 2016 Drive Report; After 36,000 miles, My LEAF Battery Can Still Be Revived??

I have proof that a gasser can be cheaper than an EV because my Corolla only used $24.20 in gas last month while my LEAF cost me $24.43!!! Moral of the story; Spin goes both ways...

For the month, the Corolla traveled 468.2 mile for the above mentioned $24.20 in gas or 5.2 cents per mile and that is all there is to that.

The LEAF using twenty three more of my hard earned cents traveled 1489.3 miles with its costs escalating due to $2.02 in public charging fees along with PUD charges totaling $24.43 or 1.6 cents per mile. Thankfully, I was saved by the 90 day free fast charging Nissan gave us for putting up with the borderline battery chemistry in the 2011 LEAF and got over 100 kwh on that program.

Since I am nearing the halfway point of my free 90 day charging, I am still working on getting the $50 worth that I declined in exchange for the fast charge sessions. But at least 2 of the chargers I might use are out of order including AV's Tumwater location and this definitely qualifies as the longest downtime stretch for that location by far. The location has been out of order several times but frequently was back up and running within a few days. Its been over 2 weeks now... :(

Now this is not being debated nearly as much as a year ago simply because there are too many people out there proving it on a daily basis but just some more evidence that the 2013 pack is a definite improvement of the 2011-12s.  We have known for quite some time that battery stats reported by the LEAF  and logged with devices such as LEAF Spy can have some pretty wide swings based on recent driving and charging habits.  Put simply; Drive your LEAF a lot and charge it fully every day and your battery stats will probably reflect a status better than reality.  Drive it modestly,  partially charge it or go several days between full charges, etc. and you see just the opposite. Numbers lower than the true state of health in your battery pack.

Well this is what I just did and yes I purposely did not charge it for high numbers which meant a lot of shorter duration charges that did not complete AKA Nissan 80% long life charging mode. ;)  As expected my numbers took a dive from the 61-62ish range to 58.44 ahr, 88.62% Hx, and 19.6 kwh available on April 25th. On that day, I drove 58.7 miles which is really far enough to keep your battery fully balanced with daily full charges.

But from the 26th to yesterday, I had a large client (they do this on last week of the month for most of the year Tues-Sat) and decided I would LEAF it every day. This required fully charging at home every night, A fast charge in the morning at work before picking up my crew and a fast charge in the afternoon after dropping off the crew.  Now the morning charge was only needed 3 of the 5 days since Renton and Tukwila are close enough but on the other 3 days for the Seattle Stores, I averaged collecting 4½ kwh which doesn't seem like much but my degradation needed it.  In the 5 days, I traveled 626.2 miles, publicly charged for 93 kwh and ended up yesterday afternoon with this

 

As impressive as this looks... I pretty much rely on 265 GIDs, 61 ahr and 94% Hx.... but still VERY nice to look at.


Fast Charge Notes;  Twice I saw a better than 100% efficiency based on kwh remaining delta / Wh
Using the pix above it would be 21.5 - whatever the charge session started at/ 12.572 (which i always reset to zero for the charge session)  Now this did not happen during the past 5 days but earlier in the month and I have not been able to reproduce this phenomena so am writing it off as user error or LEAF Spy strangeness...or something.  Other than those two times; Fast charge efficiency seems to be running between 91.4 and 94.7% efficient and no brand of charger seems to be consistently outperforming any other but as always, I will track it to see if any vendor emerges or falls from the pack.

8 comments:

  1. I visited the Tumwater AV location at least four times when I was in Washington. It's in a critical spot and I feel for you that it's been down for so long.

    ReplyDelete
    Replies
    1. Amen Brother! Them and Tahoma Market in Fife were oases for a long time!

      Delete
  2. Good to know that my lowish AHr/SOH/Hx is likely a side-effect of never charging to full. Now I'm less worried :)

    Mine's currently showing:
    2016 SV (30kwh): 900 miles, 72.2AHr, 90% SOH, 87.02Hx.

    I guess that's what happened when the car has only been charged to 100% once; the first day after we bought it.

    ReplyDelete
    Replies
    1. Thanks for the info Karlen and unless you need the maximum range, I highly doubt you are doing your battery pack any harm. Nissan BMS actively balances cells all the time and your best method for longest life is likely keeping your SOC in the middle range between 20 and 80% SOC!

      Delete
  3. Ahr SOH Hx L1/L2 QC Gids
    81.32 100% 96.91 2 5 363
    74.91 94% 89.91 29 5 340

    Here is what I'm seeing after 1 month of a new 2016 SV. Pack looked good at the dealer but the Hx has dropped liked a stone. I'm keeping my eye on this.

    ReplyDelete
    Replies
    1. Kinda suspect but not really too far out of parameters if not using a charging profile designed for distance. Keep in mind, my example inflated my stats over 10% and at least 5-7% above reality. The same can work in reverse. Poor top end balancing will do this. Keep in mind, good top end balancing is only needed if you need every extra mile you can get out of a charge. If you don't have that extreme need, then you are better off staying away from a 100% charge as much as possible. Best for long term is staying between 20 and 90% SOC. problem is the reduction in range is something I cannot do even if I had your extra capacity

      Delete
    2. I have similar LeafSpy numbers in my 2016 SV. It sat on the dealer lot over the Seattle winter, and I purchased it at the end of May. Here are my entries from picking up the car, a low spot after it sat in my garage at 70% while I was away for a week, vs just yesterday:

      6/3/16 AHr: 78.645 SOH: 98% L1/L2: 6 QC: 5
      6/15/16 AHr: 74.457 SOH: 93% L1/L2: 17 QC: 5
      7/8/16 AHr: 74.943 SOH: 95% L1/L2: 47 QC: 9

      Just goes to show the internal numbers do fluctuate, and in reality, they are just a software estimation of the battery capacity and charge level. The battery doesn't care what the software concludes, so you have to take it with a grain of salt. The real test is a full charge followed by driving to VLBW, then a full recharge. From that I did will over the rated miles due to much city driving, and the car consumed 28.4 kWh from the wall to recharge. Seems about right.

      I suspect the LeafSpy reported numbers for the 30 kWh pack are not directly comparable to the vast experiences people have had with the previous packs. Nobody outside of Nissan really knows what SOH or Hx is intended to represent.

      Delete
    3. Agreed; the only thing that matters is getting to where you need to go!

      Delete