DaveinOlyWA
Posts: 14164
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: L1/L2 counter increases by 2 to 4 each charge

Mon Feb 08, 2016 7:48 am

QueenBee wrote:
DaveinOlyWA wrote:ya, one (and only) mark against LEAF Spy is its inability to only record charging sessions and ignore circuit checks.
That's not a mark against LEAFSpy it's a mark against Nissan as LEAFSpy is just displaying what Nissan stores.
Ok, I can go that way.

yep and the one thing I wish LEAF Spy could do is "some" thinking on its own... which it does so I guess I wish it would expand its thinking...
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 25,185 miles SOH 92.23%
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

valem
Posts: 46
Joined: Thu Apr 26, 2018 6:24 pm
Delivery Date: 24 Sep 2018
Leaf Number: 405151

Re: L1/L2 counter increases by 2 to 4 each charge

Mon Aug 12, 2019 5:43 pm

cwerdna wrote:
Sun Feb 07, 2016 1:48 am
Orbiter2006 wrote: Located in Netherlands I drive a leaf bought new in January 2015. ( 24 KWH battery)
...
I drive 5 times a week around 22 miles a day and charge at night using standard EVSE cable on a 240 Volt 16 Amp outlet in my garage.
...
I use the timer to start charge after midnight ( not in the weekend) and use the 80% option to extend battery life. Charging is stopped at 7 am and I have always had normal range after a charge.
Only used 100 % charge a couple of times to handle a longer journey.
In a year I have now 5900 miles on my Odo and all looks fine.
...
Another thing is the SOH readout, it is at 88% after just one year and 5900 miles.
Temperature in Netherlands in summer rarely gets above 80 F and winters are mild, not below 23 F .
I have heard that SOH lowers faster in the first year but I had not expected this rapid decrease.
I have a yearly check-up at my dealer scheduled next week, should I raise this issue ? A "normal" user ( without OBDII dongle and Leafspy) would not notice anything unusual !!
Your SOH values might be artificially low due short drives and charging only to 80% most of the time. What about Hx?

I can't speak to your climate at all as I've only been the the Netherlands once, during December 2010.

Here are some semi-recent stats from my 2013 Leaf (built 5/2013) that's resided in the SF Bay Area:
viewtopic.php?p=449846#p449846

I don't follow my stats that closely, but yesterday (2/6/16) they worse than I remember seeing before.
Miles: 29,943
Ahr=58.13
SOH=88%
Hx=87.93%

Except for the final charge on Friday, all my charges earlier in the week were only to 80%.
"SOH values artificially low due short drives and charging only to 80% ?"

This is a very old post, but is this for real?
Does that mean that you can "artificially" lose capacity bars because of frequent partial charges rather than charging to 100% ?

So if you charge to 100% you lose SOH because you charge too high, and if you do partial charges and short drives you lose SOH because you do partial charges ?

Wait what ?
2013 Silver SL 35,800 mi
Tinted windows.
Battery replaced 05/15/17 @ 29,677 mi

cwerdna
Posts: 9765
Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: L1/L2 counter increases by 2 to 4 each charge

Mon Aug 12, 2019 10:42 pm

valem wrote:
Mon Aug 12, 2019 5:43 pm
"SOH values artificially low due short drives and charging only to 80% ?"

This is a very old post, but is this for real?
Does that mean that you can "artificially" lose capacity bars because of frequent partial charges rather than charging to 100% ?

So if you charge to 100% you lose SOH because you charge too high, and if you do partial charges and short drives you lose SOH because you do partial charges ?

Wait what ?
No. I'm talking about the behavior of the value SOH that Leaf Spy can render if charged only to 80% or less and run down partially vs. charging to 100% and doing deeper discharge cycles. To me, the deflation vs. inflation is just an instrumentation quirk.

Please see https://www.mynissanleaf.com/viewtopic. ... 11#p516611 for background about SOH and Hx.

AFAIK, Nissan has never acknowledged nor released any documentation on anything that Leaf Spy can render along with its caveats (e.g. precision, what conditions it's accurate/more or less accurate in, etc.)

Does SOH corresponding with battery capacity? Maybe... probably? We know it starts out high and tends to go down over the long term as the battery degrades. We know there's some rough correspondence between a given SOH value (or other values like AHr) vs. capacity bars but it is unknown exactly what criteria are used for a capacity bar to go away.

How accurate is SOH (or AHr or Hx)? How much of a fluctuation should we be concerned about? What about the above quirk? Who knows? Nissan hasn't told us. For all we know, they might have some internal procedure that says battery must be between x and y temps, must be charged to 100% and discharged to x% y # of times, etc. and that the accuracy is +/- n%.

'19 Bolt Premier
'13 Leaf SV w/premium package (owned)
'13 Leaf SV w/QC + LED & premium packages (lease over, car returned)

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

LeftieBiker
Moderator
Posts: 13308
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: L1/L2 counter increases by 2 to 4 each charge

Mon Aug 12, 2019 11:44 pm

I think that the 80% charging regime SOH drop is just the result of cells being unbalanced, making the overall capacity of the pack a bit less - temporarily.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

DaveinOlyWA
Posts: 14164
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: L1/L2 counter increases by 2 to 4 each charge

Tue Aug 13, 2019 6:48 am

valem wrote:
Mon Aug 12, 2019 5:43 pm
cwerdna wrote:
Sun Feb 07, 2016 1:48 am
Orbiter2006 wrote: Located in Netherlands I drive a leaf bought new in January 2015. ( 24 KWH battery)
...
I drive 5 times a week around 22 miles a day and charge at night using standard EVSE cable on a 240 Volt 16 Amp outlet in my garage.
...
I use the timer to start charge after midnight ( not in the weekend) and use the 80% option to extend battery life. Charging is stopped at 7 am and I have always had normal range after a charge.
Only used 100 % charge a couple of times to handle a longer journey.
In a year I have now 5900 miles on my Odo and all looks fine.
...
Another thing is the SOH readout, it is at 88% after just one year and 5900 miles.
Temperature in Netherlands in summer rarely gets above 80 F and winters are mild, not below 23 F .
I have heard that SOH lowers faster in the first year but I had not expected this rapid decrease.
I have a yearly check-up at my dealer scheduled next week, should I raise this issue ? A "normal" user ( without OBDII dongle and Leafspy) would not notice anything unusual !!
Your SOH values might be artificially low due short drives and charging only to 80% most of the time. What about Hx?

I can't speak to your climate at all as I've only been the the Netherlands once, during December 2010.

Here are some semi-recent stats from my 2013 Leaf (built 5/2013) that's resided in the SF Bay Area:
viewtopic.php?p=449846#p449846

I don't follow my stats that closely, but yesterday (2/6/16) they worse than I remember seeing before.
Miles: 29,943
Ahr=58.13
SOH=88%
Hx=87.93%

Except for the final charge on Friday, all my charges earlier in the week were only to 80%.
"SOH values artificially low due short drives and charging only to 80% ?"

This is a very old post, but is this for real?
Does that mean that you can "artificially" lose capacity bars because of frequent partial charges rather than charging to 100% ?

So if you charge to 100% you lose SOH because you charge too high, and if you do partial charges and short drives you lose SOH because you do partial charges ?

Wait what ?
This is true but its a limitation of Nissan's system. Personally I think its just simply a poor calculation of capacity but this is a challenge facing all automakers and the reason Nissan did not make this public info. Realize LEAF Spy shows us stuff Nissan did not want us to see. No automaker provides this level of detail

The other thing to consider is top end balancing. The charge/discharge is voltage controlled. So charging to "full" stops when the first cell hits the "full" voltage. In a "perfectly" balanced pack you actually end up with "100%" usable capacity but your pack is not perfectly balanced so you will have cells at 98%, 99%, etc. This is normal and NOTHING TO BE CONCERNED WITH

You are much better off continuing to charge to 80% ALL the time if the resulting range is sufficient. the cells balance all the time so you are not in any real danger of a cell "wandering" away from the pack. Now cell failure does happen but that is pretty rare and is not caused by unbalanced packs.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 25,185 miles SOH 92.23%
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

goldbrick
Posts: 624
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: L1/L2 counter increases by 2 to 4 each charge

Tue Aug 13, 2019 10:17 am

The SOH is just an estimate from the firmware, much like the GOM is an estimate. The only true measure of battery capacity is to charge it to 100% and then drain it to 0% while monitoring and integrating the power (voltage * current) coming out of it during that process. That would be a direct measurement of the battery's capacity under those conditions (temperature, discharge rate, etc).

Since this usually isn't possible, the BMS has to calculate capacity based on a more limited data set, eg the power consumed between x and y volts and then extrapolate from that data to calculate capacity (SOH). Repeatedly doing this extrapolation could result in errors that accumulate over time yielding an inaccurate assessment of capacity/SOH. It is not true degradation but just accumulated measurement error.

What is a known fact is that Li batteries degrade faster at high SOC, high temperature or very low SOC. Hence the advice to charge to only 80% unless the extra range is needed. Lower SOC's will reduce degradation regardless of whether the car measures it correctly or not.

valem
Posts: 46
Joined: Thu Apr 26, 2018 6:24 pm
Delivery Date: 24 Sep 2018
Leaf Number: 405151

Re: L1/L2 counter increases by 2 to 4 each charge

Tue Aug 27, 2019 6:34 pm

goldbrick wrote:
Tue Aug 13, 2019 10:17 am
The SOH is just an estimate from the firmware, much like the GOM is an estimate. The only true measure of battery capacity is to charge it to 100% and then drain it to 0% while monitoring and integrating the power (voltage * current) coming out of it during that process. That would be a direct measurement of the battery's capacity under those conditions (temperature, discharge rate, etc).

Since this usually isn't possible, the BMS has to calculate capacity based on a more limited data set, eg the power consumed between x and y volts and then extrapolate from that data to calculate capacity (SOH). Repeatedly doing this extrapolation could result in errors that accumulate over time yielding an inaccurate assessment of capacity/SOH. It is not true degradation but just accumulated measurement error.

What is a known fact is that Li batteries degrade faster at high SOC, high temperature or very low SOC. Hence the advice to charge to only 80% unless the extra range is needed. Lower SOC's will reduce degradation regardless of whether the car measures it correctly or not.
"Lower SOC's will reduce degradation regardless of whether the car measures it correctly or not."

I agree, however less capacity bars will reduce resale value, whether it is real or not.
2013 Silver SL 35,800 mi
Tinted windows.
Battery replaced 05/15/17 @ 29,677 mi

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