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Nubo
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40kWh pack speculation/what do we know?

Sat Nov 11, 2017 2:44 pm

Here's the one thing giving me pause re: 2018 LEAF:
2011 24kWh pack - serious degradation issues
2015 24kWh pack - significant improvement
2016 30kWh pack - degradation issues resurface

So, what was done to increase from 24 to 30kWh, and why did that lead to more battery problems?
- different chemistry?
- Thinner separators, etc?
- why wasn't the "Lizard" property carried forward?

What else could have been done to increase density that also decreased durability?

And, how does that bode for the 40kWh pack? MORE of the same compromises that led to problems with 30kWh pack?

My main worry is having the 40kWh pack be a product of "Go Fever" in the same way the original pack seemed to have been, sacrificing longevity to meet a date and/or capacity spec.
I noticed you're still working with polymers.

LeftieBiker
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 3:42 pm

I'm assuming substantial degradation. Since I only need 100 miles of solid real world range, the 40kwh pack would work fine for me even with that degradation. Others will want to either lease only or wait for the 60kwh pack.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

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RegGuheert
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 5:46 pm

I agree with your concerns, Nubo.
Nubo wrote:And, how does that bode for the 40kWh pack? MORE of the same compromises that led to problems with 30kWh pack?
One possibility is that they may have moved from an NMC622 cathode in the 30 kWh battery to an NMC811 cathode in the 40 kWh battery. Such a move would provide additional capacity while being a less-stable chemistry. This is PURELY speculation on my part.

(For those unfamiliar with the terminology, here is a post with some links on this topic.)
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

lorenfb
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 5:53 pm

RegGuheert wrote:I agree with your concerns, Nubo.
Nubo wrote:And, how does that bode for the 40kWh pack? MORE of the same compromises that led to problems with 30kWh pack?
One possibility is that they may have moved from an NMC622 cathode in the 30 kWh battery to an NMC811 cathode in the 40 kWh battery. Such a move would provide additional capacity while being a less-stable chemistry. This is PURELY speculation on my part.

(For those unfamiliar with the terminology, here is a post with some links on this topic.)


But would a chemistry change alone provide the additional 30% increase in Ahrs needed for the 40kWh battery?
Last edited by lorenfb on Sat Nov 11, 2017 9:30 pm, edited 1 time in total.

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LTLFTcomposite
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 6:00 pm

What do we *know* ? Squat. What should we expect given prior history and that they haven't moved into the guilded age of EVs and added TMS? Another degrading POS.
LTL
White 2012 SV delivered 10 Dec 2011 returned 25 Nov 2014 replaced with stopgap ICE Sentra
[35 months] [35K miles] [9 Bars]
2013 Volt replaced after 36 months/30k miles with ICE Rogue

SageBrush
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 7:06 pm

LeftieBiker wrote:I'm assuming substantial degradation. Since I only need 100 miles of solid real world range, the 40kwh pack would work fine for me even with that degradation. Others will want to either lease only or wait for the 60kwh pack.

30% degradation
30% winter range loss

Works out 0.7*0.7 = 50% of nameplate without any buffer
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

LeftieBiker
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Re: 40kWh pack speculation/what do we know?

Sat Nov 11, 2017 9:42 pm

I make it 90 miles in Winter with 30% capacity lost, which would be fine, especially as I would be leasing the car. 30% isn't likely to happen until my lease is almost over.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

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RegGuheert
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Re: 40kWh pack speculation/what do we know?

Sun Nov 12, 2017 1:10 am

lorenfb wrote:But would a chemistry change alone provide the additional 30% increase in Ahrs needed for the 40kWh battery?
One of the articles included in the link I provided indicates that one manufacturer has achieved a 25% increase in capacity and a reduction in manufacturing cost by moving from NMC622 to NMC811:
SK Innovation wrote:SK innovation considers that their old battery cells were enough to provide a 400 km range, while the new cells represent a 25 percent increase (100 km) to 500 km.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

lorenfb
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Re: 40kWh pack speculation/what do we know?

Sun Nov 12, 2017 2:09 am

RegGuheert wrote:
lorenfb wrote:But would a chemistry change alone provide the additional 30% increase in Ahrs needed for the 40kWh battery?
One of the articles included in the link I provided indicates that one manufacturer has achieved a 25% increase in capacity and a reduction in manufacturing cost by moving from NMC622 to NMC811:
SK Innovation wrote:SK innovation considers that their old battery cells were enough to provide a 400 km range, while the new cells represent a 25 percent increase (100 km) to 500 km.


The South Korean battery cell maker, SK innovation announced that its new NCM 811 cells will be available this December. First for battery storage systems, then in third quarter of 2018, for electric vehicles.


Yes, we'll have to wait and see if it becomes reality.

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RegGuheert
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Re: 40kWh pack speculation/what do we know?

Sun Nov 12, 2017 2:42 am

lorenfb wrote:
The South Korean battery cell maker, SK innovation announced that its new NCM 811 cells will be available this December. First for battery storage systems, then in third quarter of 2018, for electric vehicles.
Yes, we'll have to wait and see if it becomes reality.
Agreed. We do know that LG Chem is planning to supply their NCM811 cell for the 2019 LEAF. What we don't know, and what I am speculating about, is the possibility that some other vendor is supplying similar 811 cells for the 2018 LEAF. But I could be completely off-base here.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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