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OrientExpress
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Posts: 1206
Joined: Sun Aug 08, 2010 12:22 pm
Delivery Date: 10 May 2011
Leaf Number: 2331
Location: San Jose, Ca

Everything you might want to know about the '18 LEAF engineering

Tue Feb 13, 2018 6:32 pm

For all you LEAF enthusiasts out there, here is an article from SAE International that deep dives into the '18 LEAF and all of the engineering that makes it what it is today. Enjoy, as I think you will be surprised at how much improvement there is over the 1st generation LEAF. BTW, SAE Automotive Engineering is a great resource for the professional automotive engineer and armchair automotive experts too!

LEAF Turns to the 2020s
2018 LEAF SL
Gun Metalic
Delivery April 10 2018

Prior LEAF:
2014 LEAF SV
Ocean Blue
Delivery May 23 2014
50,000+ miles - all 12 bars - Same range as new - No warranty issues ever!

erco
Posts: 90
Joined: Sat Aug 05, 2017 11:32 pm
Location: Los Angeles, CA

Re: Everything you might want to know about the '18 LEAF engineering

Sun Mar 04, 2018 11:37 am

Fantastic article and resource. Thanks OE!
Ocean Blue 2014 S, 3.6kW OBC, no QC, purchased 10/21/17, 12 bars, Los Angeles
Car first sold in Buford Georgia
Dropped 1st bar 11/30/17
AmazingE 3.8 kW EVSE

DaveinOlyWA
Posts: 13133
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: Everything you might want to know about the '18 LEAF engineering

Sun Mar 04, 2018 5:24 pm

So who is volunteering to hack the chademo port so we can have an emergency power source? :)
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 8743 miles, 485 GIDs, 37.6 kwh 111.39 Ahr , SOH 96.49, Hx 114.98
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

SageBrush
Posts: 2680
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Everything you might want to know about the '18 LEAF engineering

Sun Mar 04, 2018 8:58 pm

10% degradation per 500 cycles. Environmental details were not mentioned

Ouch

Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

User avatar
Nubo
Posts: 4848
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Everything you might want to know about the '18 LEAF engineering

Sun Mar 04, 2018 9:55 pm

SageBrush wrote:10% degradation per 500 cycles. Environmental details were not mentioned

Ouch

Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.


Not so "ouch" if cycle life refers to full cycles, as the 60,000 mile claim suggests. The common use-case would be consuming only a partial cycle per drive. 15 percent degradation would extrapolate to 90,000 miles, which is far better than LEAF has performed previously.

If true, of course. ;)
I noticed you're still working with polymers.

SageBrush
Posts: 2680
Joined: Sun Mar 06, 2011 2:28 am
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Location: Colorado

Re: Everything you might want to know about the '18 LEAF engineering

Sun Mar 04, 2018 10:44 pm

Nubo wrote:
SageBrush wrote:10% degradation per 500 cycles. Environmental details were not mentioned

Ouch

Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.


Not so "ouch" if cycle life refers to full cycles, as the 60,000 mile claim suggests. The common use-case would be consuming only a partial cycle per drive. 15 percent degradation would extrapolate to 90,000 miles, which is far better than LEAF has performed previously.

If true, of course. ;)

I was guessing at average use of 50% SoC usage a day, so perhaps 2000 cycles till 80% capacity. That is about 6 years
Or 3000 cycles until 70% SoC

Right about where you would expect Nissan to be if they chose a warranty period to about match battery longevity, and pretty much in line with past Nissan behavior. The missing information has to do with climate but I don't expect Nissan to turn a new page here.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

DaveinOlyWA
Posts: 13133
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: Everything you might want to know about the '18 LEAF engineering

Mon Mar 05, 2018 6:45 am

SageBrush wrote:10% degradation per 500 cycles. Environmental details were not mentioned

Ouch

Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.


that is 75,500 miles per the EPA so you will have 11½ bars after that. Alter your charging habits to DoD of 70% or 115 miles and push that to 11½ bars @ 100,000 miles.

But then again, I am guessing unless its 1% over half a million, it won't be good enough for you because it has a Nissan nameplate.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 8743 miles, 485 GIDs, 37.6 kwh 111.39 Ahr , SOH 96.49, Hx 114.98
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

johnlocke
Posts: 278
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: Everything you might want to know about the '18 LEAF engineering

Mon Mar 05, 2018 8:31 am

500 cycles over 60000 miles equates to 120 mi per cycle. That's about 80% percent discharge per cycle most likely 90% to 10%. That would give you 200K mi for a 33.3% loss in capacity which is most likely what Nissan was aiming for. That would give you a "Lifetime" battery in that it would exceed the expected life cycle of the car itself. 1600-1700 charge and discharge cycles doesn't seem unreasonable in a moderate climate but I suspect that since the underlying chemistry hasn't changed we're going to see early failures in hot climates just like the 30 KWH battery. The larger battery will delay failures a bit but I would expect that we'll still start to see failures after the 3 year mark.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

SageBrush
Posts: 2680
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Everything you might want to know about the '18 LEAF engineering

Mon Mar 05, 2018 9:01 am

DaveinOlyWA wrote:
SageBrush wrote:10% degradation per 500 cycles. Environmental details were not mentioned

Ouch

Silver lining: at least this time around Nissan is being honest that the battery willl have poor longevity.


that is 75,500 miles per the EPA so you will have 11½ bars after that. Alter your charging habits to DoD of 70% or 115 miles and push that to 11½ bars @ 100,000 miles.

I'll quote you for posterity and giggles.

As for Nissan's god awful customer support, no reason to drag that filthy laundry into a technical discussion about battery longevity.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

johnlocke
Posts: 278
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: Everything you might want to know about the '18 LEAF engineering

Mon Mar 05, 2018 6:31 pm

Using the latest battery chemistry (NMC 811) you can get 1250 charge/discharge cycles (2.8 vdc to 4.2 vdc I.E. 100% discharge) at 45 degrees C. before you lose 20% capacity. And that's at 1C charge and discharge rates. Goes up to 1500 cycles for 20 degrees C. For a 60 KWH battery, that works out to 250K miles. What's not mentioned is long term deterioration as these kind of tests are run end to end over a period of months. If long term storage is not a problem this could be a "lifetime" battery. With 200 amp charging available, TMS will still be necessary while charging to prevent overheating the battery during DC Fast Charging during road trips. You might get away without a TMS while home charging overnight or even during normal driving but DCFC is going to require it anyway so you might as well make use of it.

If you expect to get the DCFC time down to 15 to 30 minutes, you have to use a 2-4 C charge rate which is not a problem for the battery to accept but will definitely heat up the battery. That's why you need the TMS.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

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