SageBrush
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Delivery Date: 13 Feb 2017
Location: NM

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Fri Nov 10, 2017 4:32 pm

Anecdotes have limited statistical power (duh!);
Qualitative findings are real, but that does not make them quantitative.

We know that heat and SoC are players in the degradation game, but the details and interplay are elusive. Non linear effects are hard to pin down with the best of data, and the LEAF data is a noisy mess. So people should take a modesty pill and chill out with their dogmatic assertions.

One point to throw into the heap: Elon Musk has said that routine charging of Tesla car batteries to 90% rather than 100% eliminates the lion's share of use related degradation. If that is true with a liquid cooled battery, it says even more for the passive Nissan battery.

Most people who live in 4 season climates can relax in the winter when it comes to routines to slow battery degradation, but are well advised to do the following in the summer, quant relationships missing notwithstanding:

1. Keep the car out of the heat as much as possible. This means in the shade and off hot asphalt
2. Minimize time the car sits at end charge
3. Charge to the lowest levels that are tolerably convenient
4. Try to charge when the battery has cooled off
5. Avoid parking the car in hot, poorly ventilated area. Closed garages, e.g.

'Lucky' for us, these suggestions are not typically in conflict.
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
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Location: NM

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Fri Nov 10, 2017 5:06 pm

arnis wrote:It's not that complicated. There are Leafs, incl 30kWh Leafs, that have excellent SOH no matter how
deep are the cycles, how many cycles there are, how far are they charged (80% or 100%), QC or not.
Without any other data it is possible to conclude with high degree of certainty that ALL
these factors do not play a major role in rapid degradation as there are hardly any rapid degraders
in moderate climates. They play some role, but at expected rates, giving battery a 10+ year or 200Mm lifetime.
You are playing word games.

What is "rapid" degradation ? Loss of 15% capacity in under 3 years occurs in moderate climates. That would raise a shit-storm in the Tesla world, while around here many would dismiss it as an excellent outcome. What are the physics that explains this group, and how can they reduce the degradation by half ?

The short answer is, no one has a clue with any certainty.
While cold climates like Estonia that reach summer averages into the 60s F appear to be well protected from 30% capacity loss in under 8 yrs, that leaves almost all of the US outside of the pacific NW maritime climates still scrambling for answers.
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

johnlocke
Posts: 596
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Fri Nov 10, 2017 9:22 pm

There's just one problem with short cycling the battery in a Nissan Leaf. You can't drive it very far to start with and if you limit charge and discharge cycles to 80% and 20% respectively range drops to 60-65 miles on a new 30 KWH and 48-53 miles on a new 24 KWH battery. Add in some battery deterioration and the car becomes unusable for anything but short trips. By the time the warranty kicks in you'ld be down to 35-40 miles on the 30 KWH battery.

A Tesla has a large enough battery that short cycling doesn't present any realistic limitations for daily use. The leading battery expert suggests keeping the max charge to below 4.10 VDC. Elon Musk suggests that 90% of full charge eliminates most deterioration problems. Nissan limits the max charge to 4.12 VDC per cell. Tesla actually limits ordinary charging to 80% unless you tell the car to do a full charge. NIssan should have enabled a limited charge option on newer Leafs but didn't want to take the hit on EPA mileage numbers. If I wanted to implement short cycling, I'd have to start with a 40 KWH battery at a minimum.

There's a lot of anecdotal evidence that heat is not kind to the Nissan battery. The evidence for charging habits is a lot more murky but Nissan doesn't think that charging to 100% should be a problem and all Leaf's do just that by default. Leafs in Europe and Japan don't seem to have problems due to charging to 100% If charging habits were a major factor, I'd expect to see failures all over the world. If I were to err on the side of caution, I'd probably only charge to 90% and try to avoid LBW if possible.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

LeftieBiker
Moderator
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Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Fri Nov 10, 2017 10:18 pm

The evidence for charging habits is a lot more murky but Nissan doesn't think that charging to 100% should be a problem and all Leaf's do just that by default. Leafs in Europe and Japan don't seem to have problems due to charging to 100%
Nissan dropped the 80% charge option in the US immediately after the EPA used it to lower the overall range estimate for the Leaf in 2013. Just a coincidence...? Also, I believe that the 80% charge option was retained in Europe, at least until Leaf 2. I'm sure that this too is just a coincidence...
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.

SageBrush
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Location: NM

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Fri Nov 10, 2017 11:44 pm

johnlocke wrote:The evidence for charging habits is a lot more murky but Nissan doesn't think that charging to 100% should be a problem
... Let me amend your sentence to:
[should not be a problem] for Nissan, meaning the battery should make it to the warranty end.

How reassuring. NOT
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

johnlocke
Posts: 596
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Sat Nov 11, 2017 11:21 am

SageBrush wrote:
johnlocke wrote:The evidence for charging habits is a lot more murky but Nissan doesn't think that charging to 100% should be a problem
... Let me amend your sentence to:
[should not be a problem] for Nissan, meaning the battery should make it to the warranty end.

How reassuring. NOT
How many people actually use the 80% option if it's still available in Europe or Japan? If it's used by most people over there, then I'd amend my opinion. If most don't use that option, I'd still suggest that charging isn't a major problem because their failure rates are much lower. We don't see this problem in the northern half of the U.S. either. If charging to 100% was a major factor, I'd expect the failures to be better distributed across the U.S. I'm not saying that it has no effect, just that it's probably minor compared to other effects. Nissan claims very low failure rates for the battery overall and I have no reason to believe they would lie about that. There is a cost analysis by Nissan here that says that failure rates overall are low enough that it's cheaper to replace failed batteries than re-engineer the battery. Also that the level of battery failures won't affect sales enough to be a problem.

Keep in mind that the 2018 battery is likely a one-off kind of thing with the 60 KWH battery appearing in the 2019 model using LG Chem cells. It might not be worth it to Nissan to re-engineer a dead end product. They might just announce that they have a new vastly improved battery and sweep any failures under the rug as old technology.
2016 SV, New battery at 45K mi.
Jamul, CA
San Diego East County

DaveinOlyWA
Posts: 14696
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Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Sat Nov 11, 2017 11:41 am

johnlocke wrote:
Oils4AsphaultOnly wrote:
ironmanco wrote:
I noticed in your sig that you only reference GID as a representative of the condition of the battery. Is it always a 1:1 relationship of the SOH of the battery and the GIDs?
I think so. And I think 380 GIDs was 100%? I don't have a concrete number since I didn't get the leafspy stats on day one. I did think it was rather odd that SOH was showing 100% all way to 7000 miles (~4.5 months of winter-spring driving)! So for me, I trust the GID number more, since it's a more detailed number than X %
I'd check with GaryGID to say for sure but I've never seen a report of more than 363 GID's on a new car even when the owners reported AH values over 82 AH from Leaf Spy. I think the value is software limited by the BMS. That would explain why some cars report the same value (363) for months before the the GID's value starts to drop.
he said "100%" not the full charge level of 97.7%. I think the actual 100% level is 375 btw.

FYI; not that it matters but my LEAF showed 100% beyond 25,000 miles and despite it showing about 96% now, I am fully confident I can pop it back up to 100%
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; 7059.6 mi, 95.35% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

sflores91
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Joined: Fri Feb 19, 2016 6:36 pm
Delivery Date: 20 Feb 2016

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Sat Nov 11, 2017 12:24 pm

I didn't do any leaf spy on my Nissan leaf 2016 with the 30 kwh battery. I purchased it brand in Las Vegas 02-16. I just dropped my 4th bar and received a replacement from the dealership on Tuesday 11-17. The car had about 26605 miles on it.

I love having a new pack it really makes the car feel new again. It was also nice seeing the guessometer read 126 miles instead of 55-70 depending on how fast I drove it home. With the capacity that low I regularly got about 70-80 miles a charge depending on how much free way driving I did. Surprisingly, the last charge I had on the old battery got me about 93 miles before recharging at 8%. Mind you I wasnt going all the way home. I was driving to work from a friend's house, about 10 miles surface streets.

That being said I would Level 2 charge it every night. I also do Level 3 charge when stuff would come up unexpectedly and I could make it home to charge. If I had to guess more than 10 but less than 20. Most days I works charge to 100% and drive it down to about 35-25 percent before charging. As the degradation got worse, this number would get lower. Towards the end was running the battery down to 15 to less than 5% regularly.

For the first year I bought the car I was traveling 70 miles round trip a day through a hilly route to work. This driving dropped the capacity 2 bars. Then I got a new job that only had me driving about 40 miles a day. I somehow still managed to drop the other two bars. My hope is that the warranty on the battery allows me to replace the battery at least two more times. Soon, I am going to be moving closer to work which will be about 10 miles a day. So we'll see if the car gets driven that hard.

The leaf had been a really cool car. So much so that I forgot how much gas even costs and it feels weird to pump it when I rent cars for work. Recently, I've been thinking about picking up Prius to be able to visit friends or of town, but that won't happen for at least a year or so.
2016 Nissan Leaf SL Brilliant Silver 31miles 2/21/2016

ironmanco
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Joined: Mon Dec 14, 2015 8:26 pm
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Location: Boulder, CO

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Sat Nov 11, 2017 1:11 pm

DaveinOlyWA wrote:I am fully confident I can pop it back up to 100%
Can you share with us what you can do to resurrect any battery SOH?
2016 Nissan Leaf SL Deep Blue Pearl
Mfg 12/15 Del 1/16 30 Oct 2018 50,183 mi Ahr 66.89 SOH 84% Hx 63.55% (w/Nissan sw patch)
Charging: evseupgrade L2 charging 30A circuit @ 24A shared garage heater circuit (ask me)

LeftieBiker
Moderator
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Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Sat Nov 11, 2017 1:39 pm

He's talking about multiple quick charges, combined with aggressive driving to pull power from the pack rapidly. One driver claims to have substantially improved his SOH by doing this.
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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