lorenfb
Posts: 2467
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: The 40KWH Battery Topic

Sat Sep 12, 2020 8:52 am

DaveinOlyWA wrote:
Sat Sep 12, 2020 8:47 am
lorenfb wrote:
Sat Sep 12, 2020 8:18 am
DaveinOlyWA wrote:
Fri Sep 11, 2020 7:39 pm


Interesting theory but there are a handful that would seem to counter that. The 40 likely to lose the first bar is only in the high 90's. Not sure what Hx history was previously. He has piled on the miles quite rapidly though. IIRC, he is averaging well over 20,000 miles a year
And your references for this statement are?
His LEAF Spy screenshot on Facebook
Some of us don't waste time with Facebook, so provide the actual data you're referring to.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

jmurtagh13
Posts: 23
Joined: Sun Nov 01, 2015 4:54 am
Delivery Date: 10 Mar 2018
Leaf Number: 300844
Location: Atlanta GA

Re: The 40KWH Battery Topic

Sun Sep 13, 2020 9:34 am

cwerdna wrote:
Fri Sep 11, 2020 5:49 pm
jmurtagh13 wrote:
Fri Sep 11, 2020 5:31 pm
Also my understanding is that charging at a high temperature does the most damage.
I don't think that's correct at all. I pointed to https://www.nec.com/en/global/techrep/j ... 120112.pdf when I was trying to educate Powersurge at viewtopic.php?p=508974#p508974. Page 3, section 3.1 makes no mention of charging.

Table 3 at https://batteryuniversity.com/learn/art ... _batteries talks about capacity remaining after storage at 40% vs 100% SoC at various temps. Ditto for table 2 of https://batteryuniversity.com/learn/art ... _batteries.

See my examples at https://www.mynissanleaf.com/viewtopic. ... 69#p496269. https://www.mynissanleaf.com/viewtopic. ... 95#p473995 is in Phoenix and has the same build month as me. I'm still at 11 bars now with SOH around 79.xx% in a hotter part of the SF Bay Area. That guy lost his 4th bar (at 8 bars) in late 2016.

L2 charging does heat the battery by a few degrees F, so yeah, it's better to start off charging when it's cooler so that the battery doesn't get as hot. DC FCing can really heat up the battery, esp. multiple ones in a day.

https://web.archive.org/web/20170717073 ... hp?t=22134 got his 30 kWh Leaf to a battery temp of 137 F.
Thanks for the links. I am familiar and a fan of batteryuniversity. After doing some more research (it's been awhile) it does appear that charging in it self, the chemical reaction does not significantly impact battery life at higher temperatures. The main damage, as you indicated is the rising of the battery temperature at the faster charge rates and then the battery now at a high charge level and a higher temperature that is responsible for the largest impact on battery life if left at those higher levels. So even if the TMS is letting the battery temperature rise during the charging cycle, but then bring the temperature back down afterwards, the battery is receiving a major benefit in being cool for the majority of its life, assuming the TMS is allowed to function frequently enough. What I still struggle with is why high mileage Leafs in the same climate seem to be at the same SOH at low mileage Leafs. Charge / run cycles do heat up the battery, so you would think that higher mileage Leafs would degrade faster. Also higher mileage Leafs owners would likely be charging their batteries to a high charge level.
2018 Leaf March 10, 2018
30 months, 22,186 miles
SOH 90.60

lorenfb
Posts: 2467
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: The 40KWH Battery Topic

Sun Sep 13, 2020 10:13 am

jmurtagh13 wrote:
Sun Sep 13, 2020 9:34 am
cwerdna wrote:
Fri Sep 11, 2020 5:49 pm
jmurtagh13 wrote:
Fri Sep 11, 2020 5:31 pm
Also my understanding is that charging at a high temperature does the most damage.
I don't think that's correct at all. I pointed to https://www.nec.com/en/global/techrep/j ... 120112.pdf when I was trying to educate Powersurge at viewtopic.php?p=508974#p508974. Page 3, section 3.1 makes no mention of charging.

Table 3 at https://batteryuniversity.com/learn/art ... _batteries talks about capacity remaining after storage at 40% vs 100% SoC at various temps. Ditto for table 2 of https://batteryuniversity.com/learn/art ... _batteries.

See my examples at https://www.mynissanleaf.com/viewtopic. ... 69#p496269. https://www.mynissanleaf.com/viewtopic. ... 95#p473995 is in Phoenix and has the same build month as me. I'm still at 11 bars now with SOH around 79.xx% in a hotter part of the SF Bay Area. That guy lost his 4th bar (at 8 bars) in late 2016.

L2 charging does heat the battery by a few degrees F, so yeah, it's better to start off charging when it's cooler so that the battery doesn't get as hot. DC FCing can really heat up the battery, esp. multiple ones in a day.

https://web.archive.org/web/20170717073 ... hp?t=22134 got his 30 kWh Leaf to a battery temp of 137 F.
Thanks for the links. I am familiar and a fan of batteryuniversity. After doing some more research (it's been awhile) it does appear that charging in it self, the chemical reaction does not significantly impact battery life at higher temperatures. The main damage, as you indicated is the rising of the battery temperature at the faster charge rates and then the battery now at a high charge level and a higher temperature that is responsible for the largest impact on battery life if left at those higher levels. So even if the TMS is letting the battery temperature rise during the charging cycle, but then bring the temperature back down afterwards, the battery is receiving a major benefit in being cool for the majority of its life, assuming the TMS is allowed to function frequently enough.
Right, that's the key!
jmurtagh13 wrote:
Sun Sep 13, 2020 9:34 am
What I still struggle with is why high mileage Leafs in the same climate seem to be at the same SOH at low mileage Leafs. Charge / run cycles do heat up the battery, so you would think that higher mileage Leafs would degrade faster. Also higher mileage Leafs owners would likely be charging their batteries to a high charge level.
You essentially answered your own question in your previous statement, i.e. without your last assumption.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

danrjones
Posts: 756
Joined: Wed Apr 17, 2019 8:02 am
Delivery Date: 17 Jun 2019
Location: Ridgecrest, CA

Re: The 40KWH Battery Topic

Mon Sep 14, 2020 7:13 am

danrjones wrote:
Tue Sep 08, 2020 1:32 pm
My 2018 is in the middle of an adjustment.
Normally I try and get a leaf-spy reading every day for a few days leading up to the adjustment, but this time I was not able to do so, as I was out of town and my wife was using it. So my last reading was about 5-6 days before it started. I'm not going to put all my readings just the last two before the adjustment and the current two from yesterday and today. My guess would be that SOH was around 89.28. This is the first time my SOH has ever increased in either a 3 month adjustment or the daily adjustments.

Date | SOH | AMPhr | Hx

8/28/2020 89.31 103.10 108.18
8/31/2020 89.30 103.09 108.11
9/7/2020 89.46 103.27 107.97
9/8/2020 89.87 103.75 107.84

Whether you put faith in these numbers - or not - I know some like them reported. My pack finished its adjustment. Final numbers below.

Date | SOH | AMPhr | Hx
9/11/2020 90.21 104.14 107.61
2018 Leaf SV Pearl White with Tech and All Weather, Purchased New on 5/3/19

DougWantsALeaf
Posts: 2097
Joined: Fri May 10, 2013 8:21 pm
Delivery Date: 18 May 2013
Leaf Number: 407811
Location: Chicago North Side

Re: The 40KWH Battery Topic

Mon Sep 14, 2020 8:25 am

Good news that it went up.
2019 S Plus (98.06% SOH) & 2019 SV Plus (94.77% SOH) Both Silver
2013 Leaf SV sold 2019 with 11 bars
100 Mile Club Member (Number 87)
Max Miles on 13 Leaf: 120 miles
Max Miles on 19 SV+: 242 Highway miles @ 4.5 miles/kWh

DaveinOlyWA
Posts: 15067
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: The 40KWH Battery Topic

Tue Sep 15, 2020 7:06 pm

danrjones wrote:
Mon Sep 14, 2020 7:13 am
danrjones wrote:
Tue Sep 08, 2020 1:32 pm
My 2018 is in the middle of an adjustment.
Normally I try and get a leaf-spy reading every day for a few days leading up to the adjustment, but this time I was not able to do so, as I was out of town and my wife was using it. So my last reading was about 5-6 days before it started. I'm not going to put all my readings just the last two before the adjustment and the current two from yesterday and today. My guess would be that SOH was around 89.28. This is the first time my SOH has ever increased in either a 3 month adjustment or the daily adjustments.

Date | SOH | AMPhr | Hx

8/28/2020 89.31 103.10 108.18
8/31/2020 89.30 103.09 108.11
9/7/2020 89.46 103.27 107.97
9/8/2020 89.87 103.75 107.84

Whether you put faith in these numbers - or not - I know some like them reported. My pack finished its adjustment. Final numbers below.

Date | SOH | AMPhr | Hx
9/11/2020 90.21 104.14 107.61
Up is good. In the last 3 months, I am guessing you drove less than normal?
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 13,705 mi, 93.41% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

danrjones
Posts: 756
Joined: Wed Apr 17, 2019 8:02 am
Delivery Date: 17 Jun 2019
Location: Ridgecrest, CA

Re: The 40KWH Battery Topic

Wed Sep 16, 2020 10:43 am

DaveinOlyWA wrote:
Tue Sep 15, 2020 7:06 pm
danrjones wrote:
Mon Sep 14, 2020 7:13 am
danrjones wrote:
Tue Sep 08, 2020 1:32 pm
My 2018 is in the middle of an adjustment.
Normally I try and get a leaf-spy reading every day for a few days leading up to the adjustment, but this time I was not able to do so, as I was out of town and my wife was using it. So my last reading was about 5-6 days before it started. I'm not going to put all my readings just the last two before the adjustment and the current two from yesterday and today. My guess would be that SOH was around 89.28. This is the first time my SOH has ever increased in either a 3 month adjustment or the daily adjustments.

Date | SOH | AMPhr | Hx

8/28/2020 89.31 103.10 108.18
8/31/2020 89.30 103.09 108.11
9/7/2020 89.46 103.27 107.97
9/8/2020 89.87 103.75 107.84

Whether you put faith in these numbers - or not - I know some like them reported. My pack finished its adjustment. Final numbers below.

Date | SOH | AMPhr | Hx
9/11/2020 90.21 104.14 107.61
Up is good. In the last 3 months, I am guessing you drove less than normal?
Actually, no, not really. Been working / driving to work pretty much the same.

So far mileage hasn't really seemed to be the "driving" factor in SOH for the Leaf's posted on here. Not sure what really is, assuming we can trust the leaf-spy readings. But my mileage has been pretty steady. My car is low mileage anyway, but my mileage has been steady. I think I'm at about 7300 miles but I'll have to check.
2018 Leaf SV Pearl White with Tech and All Weather, Purchased New on 5/3/19

DaveinOlyWA
Posts: 15067
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: The 40KWH Battery Topic

Wed Sep 16, 2020 8:18 pm

danrjones wrote:
Wed Sep 16, 2020 10:43 am
DaveinOlyWA wrote:
Tue Sep 15, 2020 7:06 pm
danrjones wrote:
Mon Sep 14, 2020 7:13 am



Whether you put faith in these numbers - or not - I know some like them reported. My pack finished its adjustment. Final numbers below.

Date | SOH | AMPhr | Hx
9/11/2020 90.21 104.14 107.61
Up is good. In the last 3 months, I am guessing you drove less than normal?
Actually, no, not really. Been working / driving to work pretty much the same.

So far mileage hasn't really seemed to be the "driving" factor in SOH for the Leaf's posted on here. Not sure what really is, assuming we can trust the leaf-spy readings. But my mileage has been pretty steady. My car is low mileage anyway, but my mileage has been steady. I think I'm at about 7300 miles but I'll have to check.
What's not to trust in LEAF Spy? It only parrots what the car tells it.

In checking with others who had a boost;

Half said no change in driving. There is no seasonal correlation.

A few said they drove more because it was Summer.

Only one drove less and coincidentally, his increase was the smallest. I "think" it was .07% or something in that range. FYI; he only checks stats once a month so the increase could have been bigger and a .2% loss in a month is well within the normal range so it might have been near .3%. There were 2 others who claimed no change who also had increases in that range as well.

For reference; mine happened in Summer; July 2019 and it was during a period when I drove more than any quarter the previous year.

For the rest of the time I had the car, my drop between adjustments slowed way down and the October 2019 adjustment didn't happen at all.

Finally, miles do make very little difference as you mentioned. Considering the clockwork like 90 day adjustments (or 91 for those longer quarters) it should be no surprise that time is the factor. We have more than a 150% difference in mileage driven for cars picked up between Feb and Julyish of 2018 while most are now between 88 to 91% SOH.
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 13,705 mi, 93.41% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

DougWantsALeaf
Posts: 2097
Joined: Fri May 10, 2013 8:21 pm
Delivery Date: 18 May 2013
Leaf Number: 407811
Location: Chicago North Side

Re: The 40KWH Battery Topic

Wed Sep 16, 2020 8:29 pm

Dave, do you think miles plays much of a role at all in the algorithm for the daily or quarterly adjustments?

For the quarter (late May to late August) where we say our .6x% increase (on a 62 battery), our miles were fairly normal for the quarter, but up from the covid low driving spring.
2019 S Plus (98.06% SOH) & 2019 SV Plus (94.77% SOH) Both Silver
2013 Leaf SV sold 2019 with 11 bars
100 Mile Club Member (Number 87)
Max Miles on 13 Leaf: 120 miles
Max Miles on 19 SV+: 242 Highway miles @ 4.5 miles/kWh

DaveinOlyWA
Posts: 15067
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: The 40KWH Battery Topic

Wed Sep 16, 2020 10:07 pm

DougWantsALeaf wrote:
Wed Sep 16, 2020 8:29 pm
Dave, do you think miles plays much of a role at all in the algorithm for the daily or quarterly adjustments?

For the quarter (late May to late August) where we say our .6x% increase (on a 62 battery), our miles were fairly normal for the quarter, but up from the covid low driving spring.
Its hard to say. The reality is the pool of data is weak, inconsistent and filled with "it doesn't matter" evaluations that get written off as negligible. The result is people reporting what they think is important and that means we frequently see pertinent information left out.

What is pertinent? Good question but until we know more, we should be including it until it is proven its not important enough to track.

As time goes on, we should see groups of people diverging from the pack either outperforming the masses or underperforming.

I had hoped to have an active quarter but the smoke issue has me all but DOA. Doing anything outside is simply incredibly risky and the plans for some hikes before the end of Summer looks to be all but done. RIght now the projection has me finishing the quarter in the average range around 3600-3800 miles when I was on pace to be closer to 45-4700. I am just over 400 miles for this month which is well less than half of what I was mid month in July and August.
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 13,705 mi, 93.41% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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