SageBrush
Posts: 4911
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sat Mar 31, 2018 1:07 pm

LeftieBiker wrote:The problem is that the packs will experience similarly high temps in Summer with NO QC.
This.

And QC will routinely be throttled. Nissan made a marketing mistake. The car has a dedicated L2+ charging speed.
Last edited by SageBrush on Sat Mar 31, 2018 1:13 pm, edited 1 time in total.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

SageBrush
Posts: 4911
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sat Mar 31, 2018 1:08 pm

By the way, is Nissan using the same max voltage on the 40 kWh packs as earlier generations ? I read 4.2 v for the former but I do not see anywhere near that on my LEAF
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

Joe6pack
Posts: 163
Joined: Tue Oct 09, 2012 4:57 pm
Delivery Date: 07 Oct 2012
Leaf Number: 025854

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 10:37 am

Perhaps in certain places and even that's not a given being that no new LEAFs have experienced an Arizona summer. Once Summer arrives full force we can find out the delta between ambient and battery temperature under normal driving conditions. I'm willing to bet that it would be difficult to get to 115 degrees Fahrenheit just driving around.
2012 Leaf SL leased October 4th, 2012
Braselton, GA

SageBrush
Posts: 4911
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 11:33 am

Joe6pack wrote:Perhaps in certain places and even that's not a given being that no new LEAFs have experienced an Arizona summer. Once Summer arrives full force we can find out the delta between ambient and battery temperature under normal driving conditions. I'm willing to bet that it would be difficult to get to 115 degrees Fahrenheit just driving around.
Look up Newton's law of Cooling and Heating and then estimate the pack's specific heat capacity.
It is not difficult to model the '18 LEAF in a summer climate from the information now available.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

LeftieBiker
Moderator
Posts: 15034
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 12:10 pm

Joe6pack wrote:Perhaps in certain places and even that's not a given being that no new LEAFs have experienced an Arizona summer. Once Summer arrives full force we can find out the delta between ambient and battery temperature under normal driving conditions. I'm willing to bet that it would be difficult to get to 115 degrees Fahrenheit just driving around.
The ambient temperature doesn't have to be 115F to get the pack to that temp or higher. I'd guess that 90F and some vigorous driving would do it. So would sustained temps in the 80s, combined with nights that stay in the 70s or warmer. In a typical July week in North America 2018 Leaf drivers will want to park their cars (in the shade) and leave them.
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.

lorenfb
Posts: 2441
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 12:25 pm

SageBrush wrote:
Joe6pack wrote:Perhaps in certain places and even that's not a given being that no new LEAFs have experienced an Arizona summer. Once Summer arrives full force we can find out the delta between ambient and battery temperature under normal driving conditions. I'm willing to bet that it would be difficult to get to 115 degrees Fahrenheit just driving around.
Look up Newton's law of Cooling and Heating and then estimate the pack's specific heat capacity.
It is not difficult to model the '18 LEAF in a summer climate from the information now available.
It would be insightful, if those with an '18 Leaf, or the 30 kWh, would use LeafSpy and post the value for the battery's internal resistance.
This would provide a key parameter of their battery chemistries and the thermal effects from multiple QCs/driving leading to battery
degradation. That data (battery resistance) for the earlier Leafs have been posted. If one assumes that the later Leafs have the same
battery thermal resistance to ambient, but a greater series resistance, those batteries would potentially remain hotter longer from
QCs/driving. The implication then, given the lack of TMS, is greater battery degradation than earlier Leafs.
#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

DaveinOlyWA
Posts: 14877
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 3:21 pm

How do we determine internal resistance from LEAF Spy? If you are talking about HX, well my internal resistance is super high. I just checked its 115.75%
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; 11,333.1 mi, 93.73% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

lorenfb
Posts: 2441
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 3:47 pm

DaveinOlyWA wrote:How do we determine internal resistance from LEAF Spy? If you are talking about HX, well my internal resistance is super high. I just checked its 115.75%
The internal resistance is measured by taking the change in battery output voltage divided by a change in battery current - ohms.
This is usually done with max load on the battery, i.e. with the Leaf at full acceleration from a stop for a few seconds. Don't think the Hx
indicated as a percent is a measure of battery resistance, which is either in mohms or ohms. My Hx today is about 70 for 60F,
which does correlate to some of the actual readings, if Hx really is in mohms which I doubt. Based on your Hx = 115 and if it really is the
battery resistance, then your battery has all most 2X the resistance as my 2013. Here're my resistance reading over a number of years:

11/20/14 -13,700 miles, 76 mohms per LeafDD, 20 Deg, 73% SOC
11/27 -13,800 miles, 67 mohms per LeafDD, 25 deg, 63% SOC
11/30 - 13,900 miles, 56 mohms per LeafDD, 27 deg, 71% SOC
12/2 - 14.100 miles, 55 mohms per LeafDD, 28 deg, 67% SOC
12/16 - 14,500 miles, 89 mohms per LeafDD, 15 deg, 93% SOC
12/27/14 - 14,800 miles, 103 mohms per LeafDD, 11 deg, 24% SOC
3/10 - 17,400 miles, 60 mohms per LeafDD, 30 deg, 73% SOC
3/14 - 17, 550 miles, 56 mohms per LeafDD, 32 deg, 47% SOC
4/14 - 19,100 miles, 59 mohms per LeafDD, 25 deg. 38% SOC
5/4 - 19,989 miles, 64 mohms per LeafDD, 24 deg. 48% SOC
5/15 - 20,400 miles, 73 mohms per LeafDD, 20 deg. 41% SOC
5/22 - 20,700 miles, 58 mohms per LeafDD, 28 deg. 50% SOC
12/10/15 - 28,000 miles, 90 mohms per LeafDD, 19 deg. 92% SOC
4/5 - 32,000 miles, 74 mohms per LeafDD, 24 deg, 55% SOC
5/16 - 33,700 miles,89 mohms per LeafDD, 22 deg, 47% SOC
5/16 - 33.700 miles, 58 mohms per LeafDD, 31 deg, 76% SOC
10/5 - 39,300 miles, 100 mohms per LeafDD, 22 deg, 50% SOC
10/6 - 39,400 miles, 61 mohms per LeafDD, 30 deg, 51% SOC
10/7 - 39,500 miles, 80 mohms per LeafDD, 25 deg, 56% SOC
10/15 - 40,000 miles, 71 mohms per LeafDD, 27 deg, 45% SOC
10/30 - 41,000 miles, 74 mohms per LeafDD, 23 deg, 66% SOC
12/26/16 - 43,000 miles, 110 mohms per LeafDD, 13 deg, 77% SOC
6/10/17 - 49,600 miles, 89 mohms per LeafDD, 19 deg, 70% SOC
7/1/17 - 51,000 miles, 62 mohms per LeafDD, 33 deg, 44% SOC
8/15/17 - 53,400 miles, 61 mohms per LeafDD, 35 deg, 57% SOC

Those values were taken from LeafDD which actually calculates battery resistance. Maybe Jim (LeafSpy) removed it from LeafSpy,
as I can't seem to find it on my LeafSpy Pro running on iOS. Will check my Android device. Also will post on the LeftSpy thread and ask Jim.

Dave: You could monitor the battery's voltage drop and its peak current when you do a hard acceleration and just calculate it.
Example: Battery voltage goes from 370 to 360 as the current peaked at 100 amps. That results in .100 ohms or 100 mohms.
#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

Joe6pack
Posts: 163
Joined: Tue Oct 09, 2012 4:57 pm
Delivery Date: 07 Oct 2012
Leaf Number: 025854

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 8:33 pm

I am a mechanical engineer, so I get how the heat is generated in the battery and how it is dissipated. Assuming no solar loading, the battery would be at ambient temperature. Once current begins flowing into or out of the battery, it begins to heat up as a function of the internal resistance (as lorenfb pointed out) and the amount of current flowing. Of course, under normal driving conditions, there shouldn't that much current. On the interstate, where you may see higher current draws, you are also going to have a lot of air flow around the battery pack.

I live in Georgia and even on the hottest days, I don't think I've seen the 24 kWh battery hit 115 degrees F just driving around - even on the interstate. If we knew all the variables, we could probably rough something out, but it's probably easier just to take some readings using LEAFSpy.
2012 Leaf SL leased October 4th, 2012
Braselton, GA

lorenfb
Posts: 2441
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sun Apr 01, 2018 8:52 pm

Joe6pack wrote:I am a mechanical engineer, so I get how the heat is generated in the battery and how it is dissipated. Assuming no solar loading, the battery would be at ambient temperature. Once current begins flowing into or out of the battery, it begins to heat up as a function of the internal resistance (as lorenfb pointed out) and the amount of current flowing. Of course, under normal driving conditions, there shouldn't that much current. On the interstate, where you may see higher current draws, you are also going to have a lot of air flow around the battery pack.

I live in Georgia and even on the hottest days, I don't think I've seen the 24 kWh battery hit 115 degrees F just driving around - even on the interstate. If we knew all the variables, we could probably rough something out, but it's probably easier just to take some readings using LEAFSpy.
1. Yes, my experience also with my 24kWhr '13 Leaf.
2. If the later batteries have a higher internal resistance, then both QCing and driving will contribute to more battery heat and
temperature rise than the earlier battery.
3. It's questionable the amount of cooling that results from airflow around the Leaf's battery as it's moving.
4. Some owners of the 30kWhr Leafs express higher battery temps while driving and charging than the earlier Leafs.
5. Once speeds exceed about 45-55 MPH, the battery current increases in a significant non-linear form causing
battery heat (I^2 X R) to compound.
#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

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