LeftieBiker
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Tue Mar 27, 2018 3:02 pm

Seems all the theories are similar in the fact that Nissan packed more cells into the same space
No. The number of cells, and thus the voltage, is the same. Each cell holds more energy, thus producing a higher capacity. People seem to find this hard to understand, so think of it as replacing 2 AA carbon-zinc cells in a little flashlight with two AA alkaline cells. Same number of cells, same size, same voltage, but more energy available.
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RegGuheert
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Tue Mar 27, 2018 4:58 pm

LeftieBiker wrote:
Seems all the theories are similar in the fact that Nissan packed more cells into the same space
No. The number of cells, and thus the voltage, is the same. Each cell holds more energy, thus producing a higher capacity. People seem to find this hard to understand, so think of it as replacing 2 AA carbon-zinc cells in a little flashlight with two AA alkaline cells. Same number of cells, same size, same voltage, but more energy available.
While it is true that there are no additional cells in the 2018 LEAF battery, the fact is that the cells are thicker than they were in previous versions. They are also packaged differently within the modules (8 cells per module instead of 4) and the modules are arranged differently within the pack in order to take advantage of empty space that was there. The bottom line is that they figured out out to fit more stuff into the same box.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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Nubo
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Tue Mar 27, 2018 6:53 pm

RegGuheert wrote:
LeftieBiker wrote:
Seems all the theories are similar in the fact that Nissan packed more cells into the same space
No. The number of cells, and thus the voltage, is the same. Each cell holds more energy, thus producing a higher capacity. People seem to find this hard to understand, so think of it as replacing 2 AA carbon-zinc cells in a little flashlight with two AA alkaline cells. Same number of cells, same size, same voltage, but more energy available.
While it is true that there are no additional cells in the 2018 LEAF battery, the fact is that the cells are thicker than they were in previous versions. They are also packaged differently within the modules (8 cells per module instead of 4) and the modules are arranged differently within the pack in order to take advantage of empty space that was there. The bottom line is that they figured out out to fit more stuff into the same box.
And apparently none of the (apparently theoretical) "passive cooling" magic they tried to dazzle us with after the last battery debacle. Or at least no effective passive cooling. If you can't cool the pack in 2 hours of mild driving in a below-freezing British winter, then your passive cooling design sucks donkey balls.

https://youtu.be/QKlLuPLgKn0
I noticed you're still working with polymers.

borugee
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Tue Mar 27, 2018 7:34 pm

cwleaf2 wrote:
borugee wrote:The issue is real, Some QC charging stations charge by the minute, so it is not only our time is wated, our money is wasted, while waiting. Here is my experience on a 80F-85F day, doing 2 - QCs. 1st QC started slowing down around 60%. 2nd QC was slow all the way when my battery was at 20%. However my battery gauge on car never hit RED. Leaf SPY temp. was 112F after the 2nd QC.

Check out my Leaf Spy graphs. (Not looking good). Issue for Nissan is probably they can't fix this on software. They need a way to cool the battery. When you charge batteries heat up. Higher the density, more heat it generate, and need to decipate. (40kWh battery same size as 24kWh)


First QC Graph
https://drive.google.com/open?id=11NoxZ ... 42Ze3MzWhf

Second QC Graph
https://drive.google.com/open?id=1185z8 ... 6LwIP6dRHV
Thanks for your data. It is very interesting to finally hear about problems on the US model of the 40 kWh LEAF II.

But to get a detailed picture, I would need more information like:

Are you sure that this particular charger can deliver 45 to 50 kW to your 40 kWh LEAF? Does it do so on your 30 kWh LEAF?

Do you have LeafSpy Pro logs about several complete charges from low battery (10-20%) up to some 80% SOH?

Thank you very much for your help.
The charge is from a EVGO DCFC charger, I don't have 30kWh LEAF anymore. But I have charged from the same charger before and remember charge speed of 36kW (Start of charging when battery is low) to 40kW (When battery get close to 80%) sustained on this charger and then start to drop.

I have charged few times as the 1st charge on a DCFC and those times, charge rate started dropping around 65% battery on 40kWh car. I don't have logs on Leaf Pro for these.
Borugee
2018 SL ; 03/18 Delivery ; Dallas TX ; @10k Mile ; SOH=94.83,AHr=109.47,Hx=109.12

DaveinOlyWA
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Wed Mar 28, 2018 4:33 am

First charge (or actually any charge) where batt temps are below 90º F will start at or near full speed with the ramp down starting between 55 - 64%.

The interesting thing is the warmer the pack at the start, the later the ramp down. On a cold pack, ramp down starts at 55% the "actual" temp doesn't seem to matter.

The other day, I did 3 QC's


first one; batt temps started in mid 50's, ended in low 90's. SOC 4 - 57%. ramp down 54%.

2nd one; batt temps 85-90º, ended 115º SOC 27- 78% ramp down 64%

3rd one (not expecting much) batt temps started 113, ended at 115 (batt temps on charge graph was nearly flat from halfway thru 2nd charge)

started at 22 KW (65 amps) charged 23 mins, SOC 75-91% (59 amps)

Thought about putting more mileage between charge 2 and 3 but the temps were dropping too fast and without AV there is no convenient QC farther down the road...
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
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RegGuheert
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Wed Mar 28, 2018 4:56 am

DaveinOlyWA wrote:first one; batt temps started in mid 50's, ended in low 90's. SOC 4 - 57%. ramp down 54%.

2nd one; batt temps 85-90º, ended 115º SOC 27- 78% ramp down 64%

3rd one (not expecting much) batt temps started 113, ended at 115 (batt temps on charge graph was nearly flat from halfway thru 2nd charge)

started at 22 KW (65 amps) charged 23 mins, SOC 75-91% (59 amps)
That doesn't look horrible to me. It seems that Nissan has decided they don't want the battery temperature to go above 115F.

At a charging rate of 22 kW, the battery "hot spot" temperature is certainly above 115F, perhaps as high as 150F. I don't know about NMC622, but some Li-ion batteries have temperatures above which VERY bad things happen. In this case, it's more likely Nissan just wants to limit the highest temperatures that the hottest cells in the pack will see during charging in order to limit their degradation rate relative to the coolest cells. Remember, the pack's capacity is roughly the capacity of the worst cell-pair times the number of cell-pairs.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

DaveinOlyWA
Posts: 14946
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Wed Mar 28, 2018 5:02 am

RegGuheert wrote:
DaveinOlyWA wrote:first one; batt temps started in mid 50's, ended in low 90's. SOC 4 - 57%. ramp down 54%.

2nd one; batt temps 85-90º, ended 115º SOC 27- 78% ramp down 64%

3rd one (not expecting much) batt temps started 113, ended at 115 (batt temps on charge graph was nearly flat from halfway thru 2nd charge)

started at 22 KW (65 amps) charged 23 mins, SOC 75-91% (59 amps)
That doesn't look horrible to me. It seems that Nissan has decided they don't want the battery temperature to go above 115F.

At a charging rate of 22 kW, the battery "hot spot" temperature is certainly above 115F, perhaps as high as 150F. I don't know about NMC622, but some Li-ion batteries have temperatures above which VERY bad things happen. In this case, it's more likely Nissan just wants to limit the highest temperatures that the hottest cells in the pack will see during charging in order to limit their degradation rate relative to the coolest cells. Remember, the pack's capacity is roughly the capacity of the worst cell-pair times the number of cell-pairs.

agreed. Here you see still charging at 35 KW when temps first hit 115º. So stop charge, go 15 miles down road, start charge at nearly same temp and it drops to 22 KW (see gap on green line) so its looking like starting temp is key.

2nd charge batt temps 84.3/89.2/90.4

https://photos.app.goo.gl/iVrVaPlPnQNh4fcI2
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
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cwleaf2
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Fri Mar 30, 2018 12:49 pm

DaveinOlyWA wrote:
RegGuheert wrote:
DaveinOlyWA wrote:first one; batt temps started in mid 50's, ended in low 90's. SOC 4 - 57%. ramp down 54%.

2nd one; batt temps 85-90º, ended 115º SOC 27- 78% ramp down 64%

3rd one (not expecting much) batt temps started 113, ended at 115 (batt temps on charge graph was nearly flat from halfway thru 2nd charge)

started at 22 KW (65 amps) charged 23 mins, SOC 75-91% (59 amps)
That doesn't look horrible to me. It seems that Nissan has decided they don't want the battery temperature to go above 115F.

At a charging rate of 22 kW, the battery "hot spot" temperature is certainly above 115F, perhaps as high as 150F. I don't know about NMC622, but some Li-ion batteries have temperatures above which VERY bad things happen. In this case, it's more likely Nissan just wants to limit the highest temperatures that the hottest cells in the pack will see during charging in order to limit their degradation rate relative to the coolest cells. Remember, the pack's capacity is roughly the capacity of the worst cell-pair times the number of cell-pairs.

agreed. Here you see still charging at 35 KW when temps first hit 115º. So stop charge, go 15 miles down road, start charge at nearly same temp and it drops to 22 KW (see gap on green line) so its looking like starting temp is key.

2nd charge batt temps 84.3/89.2/90.4

https://photos.app.goo.gl/iVrVaPlPnQNh4fcI2
Thanks for your rapid charging graph! This is exactly the same problem as we saw on your LEAF 2.0 in Europe.

Here are the numbers from Bjørn's 600 mile yesterday in Norway:

Second charge:
T1: 32,0º T2: 29,7º T3: 22,5º SOC: 16,1% Charge: 42.6 kW
T1: 40,4º T2: 38,9º T3: 30,6º SOC: 42,4% Charge: 44.4 kW
T1: 44,0º T2: 42,6º T3: 34,1º SOC: 54,3% Charge: 45.0 kW
T1: 47,9º T2: 46,6º T3: 37,9º SOC: 68,5% Charge: 36.2 kW
T1: 48,3º T2: 47,0º T3: 38,4º SOC: 70,8% Charge: 34.3 kW

Third charge:
T1: 45,4º T2: 41,8º T3: 32,6º SOC: 48,7% Charge: 22.1 kW
T1: 46,6º T2: 42,7º T3: 33,3º SOC: 56,1% Charge: 21.1 kW

Later charge:
T1: 41,0º T2: 34,4º T3: 23,5º SOC: 34,9% Charge: 25.9 kW
T1: 44,4º T2: 37,7º T3: 26,6º SOC: 54,7% Charge: 26.1 kW
T1: 46,0º T2: 39,2º T3: 28,5º SOC: 64,4% Charge: 26.0 kW

Latest charge:
T1: 37,1º T2: 29,6º T3: 18,4º SOC: 15,1% Charge: 30.9 kW
T1: 42,9º T2: 36,2º T3: 25,7º SOC: 52,2% Charge: 29.7 kW
T1: 44,4º T2: 37,8º T3: 27,6º SOC: 60,9% Charge: 29.2 kW

Last charge:
T1: 39,6º T2: 32,7º T3: 22,2º SOC: 21,8% Charge: 26.1 kW
T1: 42,3º T2: 35,3º T3: 24,8º SOC: 48,0% Charge: 26.4 kW
T1: 44,3º T2: 37,3º T3: 26,7º SOC: 59,2% Charge: 27.0 kW

Joe6pack
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sat Mar 31, 2018 6:49 am

So Nissan has decided to protect the battery from excessive temperatures by limiting charge rate on successive fast charges. Seems like a a good idea.
2012 Leaf SL leased October 4th, 2012
Braselton, GA

LeftieBiker
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Re: Possible Widespread 2018 Traction Battery Quick Charge Problems

Sat Mar 31, 2018 11:43 am

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

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