cwerdna
Gold Member
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Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Battery temp management for new leaf

Sun Oct 22, 2017 5:01 pm

Powersurge: Your post has got to be amongst the most absurd on heat related degradation I've heard here ever since maybe 2013. But at the same time, I can understand why you're making such statements as you weren't on MNL back in May 2012 (you joined in Oct 2015) and if your Leaf was bought or leased as new in Dec 2014, you have a lizard battery (best so far) Leaf. Also, you have the benefit of very reduced degradation in winter and a not blazing hot climate like Phoenix. (Example Phoenix crazy temps at viewtopic.php?p=306687#p306687.)

If you had a pre-4/2013 Leaf and lived in Phoenix or Texas or a hot part of So Cal and compared notes w/those in mild climate climates like those in Oregon or the Seattle area, you'd think differently.
powersurge wrote:I think all this worry and complaint about battery cooling and deterioration is all a myth that some are using to either discredit the Nissan company or for Nissan to blame battery deterioration on temperature rather than time. If all members recall their past experience, they may see my point.
...

Let's step back. Nissan in the past made claims like the ones at viewtopic.php?f=30&t=22446&p=469608&hilit=percent+perry#p469608 (70 to 80% remaining after to year life, we don't need thermal management, etc.)

We first started seeing capacity bars being lost in May 2012 with viewtopic.php?f=30&t=8802, that ballooned into an over 785 page thread. viewtopic.php?f=30&t=9694 is a summary. There ended up being a lot of noise in the Phoenix local media, on MNL and elsewhere. TonyWilliams w/the help of other folks here ran a range test, results at https://web.archive.org/web/20130115102 ... p?p=228326 posted on Sept 18, 2012 (first deliveries of Leaf were in Dec 2010). Leaf had only been out ~21 months and yet we already had 1 to 4 bar losers and no capacity warranty either. So... 30+% loss in under 2 years vs. 10????

Some of the Phoenix Leafers had their cars collected by Nissan temporarily for testing. TickTock actually met w/Nissan engineers on this.
viewtopic.php?p=230478#p230478
viewtopic.php?p=230575#p230575

It seems like the above and an unbeknownst to us Klee class action lawsuit forced Nissan to provide a retroactive 5 year/60K capacity warranty: viewtopic.php?t=13192.

You've also ignored literature stating capacity loss reduction is worse at higher temps (e.g. http://batteryuniversity.com/learn/arti ... _batteries, but that's not the same chemistry used in the Leaf). There are numerous chemistries (http://batteryuniversity.com/learn/arti ... ithium_ion), some more sensitive to high temps than others.

viewtopic.php?f=30&t=9694 has a quote from Charles Whalen
the LiMn2O4 chemistry, that both GM and Nissan are using in the Volt and Leaf, being the most heat sensitive and having the shortest life at higher ambients)

I personally know 2 folks in my part of the Bay Area who lost 4 bars on their '11 or '12 Leaf in time to get their battery replaced under capacity warranty. There are many more.

As for cycling vs. temp: http://www.greencarreports.com/news/108 ... red-monday commutes 130 miles/day in his Leaf. He has to charge fully on both ends but he lives in a cool climate.
viewtopic.php?f=27&t=12781 - at ~2 year mark, he lost 1 bar at 76K miles. Compare that to the <21 month old Phoenician Leafs w/WAY less mileage but blazing heat that were down 1-4 bars.

https://www.facebook.com/groups/seattle ... 036995594/ in the mild PNW lost his first bar on his '13 at 92.7K miles.

As I posted at viewtopic.php?f=6&t=24023&p=496269&hilit=phoenix+contrast#p496269 a pointer to viewtopic.php?p=473995#p473995, this guy is in Phoenix.
elec7ric wrote:I got my new 2013 SL (manufactured 5/2013 ) on 9/30/2013. Lost my first bar 5/2015, second bar 9/2015, third bar 5/2016 and forth bar 8/23/2016 (31,400 miles). First 21 months mostly charged L1/L2 to 80% (home and work). My drive was 55 miles round trip with about 75% highway. As capacity started to go away, I had to charge more often to 100%, however, I tried my best to keep it fully charged as little as possible (extreme Phoenix temperatures).

My 5/2013 built '13 that I bought used in July 2015 STILL has all 12 capacity bars and I'm past 49,2K miles. From Leaf Spy, I am getting close to losing 1 bar (SOH at around 86%, Hx at around 83.92%)

The 6/2013 built '13 Leaf I leased for 2 years, I have a screenshot of the stats near turn in. On 7/23/2015, was at AHr: 58.57, SOH: 89%, Hx: 88.89%, odo: 23,342 miles. It had 12 bars at turn in.

I also have a screenshot of the 5/2013-built '13 Leaf I'm driving now on 7/16/2015 showing AHr: 60.15, SOH, 91%, Hx: 92.12%, odo: 23,850 miles. It had 12 bars when I purchased in July 2015 and still does now.

We later discovered that it seems '13 Leafs built 4/2013 and later do MUCH better in terms of degradation than pre-4/2013 built Leafs.

GerryAZ in Phoenix has also given a comparison of how his lizard battery is doing vs. previous ones: viewtopic.php?p=499072#p499072 and viewtopic.php?f=27&t=24407&p=502456&hilit=11+bars+2011#p502456.

Prior to lizard battery announcement (viewtopic.php?f=4&t=17168), Nissan was talking about a "hot" battery in testing that's more heat resistant. At viewtopic.php?t=23983, I pointed to a paper at http://www.nec.com/en/global/techrep/jo ... 120112.pdf (Leaf batteries are made by AESC, a JV between Nissan and NEC, soon to be sold to a Chinese company) which discusses degradation depending on temp and a newly developed cell (maybe the lizard battery?) that degrades less at high temps.

Some folks that got replacements before the "hot"/lizard battery was available were supposed to get coupons for another swap to the better "hot" battery. Some pointers at viewtopic.php?p=499828#p499828.

You should monitor viewtopic.php?f=30&t=23606 on the disappointing 30 kWh batteries. There are already 1 to 4 bar losers (usually in hotter climates). There are somewhere between 2 and 4 4 bar losers that we know of. You can't blame this stuff on cycling vs. what GerryAZ has already done in Phoenix on his '15 lizard battery.

You should also monitor all the other battery degradation threads. You will see a very strong correlation between hotter climates (doesn't need to be Phoenix-level) and worse degradation.

Below's a Sacramento lizard battery car, for instance. It's no surprise that it's already in worse shape than my 5/2013 built Leaf.
viewtopic.php?p=504601#p504601
viewtopic.php?p=504665#p504665

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

SageBrush
Posts: 1496
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Battery temp management for new leaf

Sun Oct 22, 2017 5:44 pm

WetEV wrote:Arrhenius's law.

Batteries have unwanted side reactions that degrade the chemistry of the cell. Roughly every 10C the rate of these reactions will double. So if your battery gets 10C warmer for a day, then it degrades as much as two normal days in your climate. Or if you are American, 14F warmer.

So does it matter? Yes, but not very much unless you do this a lot. As I've started to take trips like this more frequently, I'm no longer in contention for the 100k miles on a 24kWh battery before losing the first bar competition. Oh, and I'm not disappointed in how fast my battery is aging. The battery isn't "crappy", but isn't the best choice for vary hot places.

Every 10C is 18F more

Phoenix is a poster child for heat related battery degradation but there is a large swath of the US that has an ambient average annual temperature 10C higher than Seattle. And ever more problematic, summers that are 20C hotter than Seattle are common. This works out to a large community of LEAF owners that are seeing (as expected by Arrhenius' law) 2.5-3x faster degradation than you.

And by the way, Seattle has another advantage besides low average ambient: the generous rain keeps the roads cool. So while I agree entirely that a LEAF can have a somewhat reasonable life in Seattle or similar climate, most of the US is LEAF inhospitable.
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

Dooglas
Posts: 176
Joined: Thu Apr 03, 2014 10:08 pm
Delivery Date: 04 Jan 2017
Leaf Number: 314779
Location: Oregon City, OR

Re: Battery temp management for new leaf

Sun Oct 22, 2017 6:44 pm

SageBrush wrote:
edatoakrun wrote:Why do those who have such serious anxiety regarding battery temperatures in passively manged packs keep buying LEAFs, and continue sharing their insecurities on this forum?

Not insecurities, disappointment with how fast the battery is aging.
Should they have known how crappy the battery is before purchase ?
Perhaps, but now they are doing their part to save others from the same fate. You know, to reduce your annoyance.

Actually, edatoakrun is asking a fairly good question. Yes, a substantial case can be made for rapid battery degradation in pre 4/13 (primarily '11 and '12) LEAFs in places like Southern Arizona. And providing information to potential buyers on the actual performance of new battery pack formulations is certainly a useful thing to do. But dedicating an entire website to endless tirades about worst case degradation of the '11/'12 battery packs is getting a bit tedious. For those who don't want a passively cooled EV - don't buy one. And for those who don't like the way Nissan dealt with the situation - scratch them off your list. Going to have to move on sooner or later.
2013 Leaf SV - lease ended, 2016 Leaf S30

cwerdna
Gold Member
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Joined: Fri Jun 03, 2011 4:31 pm
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Location: SF Bay Area, CA

Re: Battery temp management for new leaf

Sun Oct 22, 2017 6:56 pm

Dooglas wrote:Actually, edatoakrun is asking a fairly good question. Yes, a substantial case can be made for rapid battery degradation in pre 4/13 (primarily '11 and '12) LEAFs in places like Southern Arizona. And providing information to potential buyers on the actual performance of new battery pack formulations is certainly a useful thing to do. But dedicating an entire website to endless tirades about worst case degradation of the '11/'12 battery packs is getting a bit tedious.

It's not even the worst case. I wish I could find the thread where I asked '11 and '12 Leaf batteries essentially, how many '11 or '12 Leafs will still be on their original batteries and have at least 70 to 80% of original capacity. I got a couple answers of 0.

The 30 kWh batteries are NOT holding up well either (viewtopic.php?f=30&t=23606) w/somewhere between 2 and 4 4 bar losers beside a bunch of 1 to 3 bar losers. So, it is a legitimate concern to wonder how well the 40 kWh packs will hold up w/no active cooling.

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

GerryAZ
Gold Member
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Location: Phoenix, AZ

Re: Battery temp management for new leaf

Sun Oct 22, 2017 7:06 pm

Sagebrush,

I disagree with your statement that "most of the US is LEAF inhospitable" because I have driven nearly 100,000 miles on electricity in the brutal heat of Phoenix. It is true that the traction batteries deteriorate faster here, but 12-volt batteries in the LEAF last longer than typical for gasoline or Diesel engine cars. There is almost no routine maintenance required on the LEAF (just annual battery checks, routine inspections, and brake fluid flush every 2 years). Gasoline and Diesel engine vehicles require more frequent maintenance to cope with the heat here vs. cooler climates so there are trade offs.

It will be interesting to see what Nissan does about the 30 kWh batteries that appear to be losing capacity faster than the 2015 "lizard" batteries.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

Dooglas
Posts: 176
Joined: Thu Apr 03, 2014 10:08 pm
Delivery Date: 04 Jan 2017
Leaf Number: 314779
Location: Oregon City, OR

Re: Battery temp management for new leaf

Sun Oct 22, 2017 7:21 pm

GerryAZ wrote:It will be interesting to see what Nissan does about the 30 kWh batteries that appear to be losing capacity faster than the 2015 "lizard" batteries.

Well, one thing they certainly will do. They will honor the current extended battery warranty, whatever happens with battery capacity thru time.
2013 Leaf SV - lease ended, 2016 Leaf S30

Dooglas
Posts: 176
Joined: Thu Apr 03, 2014 10:08 pm
Delivery Date: 04 Jan 2017
Leaf Number: 314779
Location: Oregon City, OR

Re: Battery temp management for new leaf

Sun Oct 22, 2017 7:28 pm

cwerdna wrote:It's not even the worst case. I wish I could find the thread where I asked '11 and '12 Leaf batteries essentially, how many '11 or '12 Leafs will still be on their original batteries and have at least 70 to 80% of original capacity. I got a couple answers of 0.

Hmmm, You asked how many '11 and '12 LEAFs are still on their original battery pack and have 70% to 80% of original capacity. And 2 people responded by guessing none?!? What were the other guesses? How is that useful?
2013 Leaf SV - lease ended, 2016 Leaf S30

cwerdna
Gold Member
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Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Battery temp management for new leaf

Sun Oct 22, 2017 7:32 pm

Dooglas wrote:
cwerdna wrote:It's not even the worst case. I wish I could find the thread where I asked '11 and '12 Leaf batteries essentially, how many '11 or '12 Leafs will still be on their original batteries and have at least 70 to 80% of original capacity. I got a couple answers of 0.

Hmmm, You asked how many '11 and '12 LEAFs are still on their original battery pack and have 70% to 80% of original capacity. And 2 people responded by guessing none?!? What were the other guesses? How is that useful?

I wish I could find the thread. It was intended to be a poll. It illustrates how far short Nissan fell short of their claims (see viewtopic.php?f=30&t=22446&p=469608&hilit=percent+perry#p469608).

I doubt very many (if any) in the mild Pacific NW at 10 years on an '11 or '12 Leaf that's still on the original pack will have 70% capacity remaining.

There was a similar thread covering those Leafs but with 80% remaining after 5 years: viewtopic.php?f=27&t=16236.

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

johnlocke
Posts: 178
Joined: Fri Jan 08, 2016 3:47 pm
Delivery Date: 14 Dec 2015
Leaf Number: 300582

Re: Battery temp management for new leaf

Sun Oct 22, 2017 7:50 pm

powersurge wrote:I think all this worry and complaint about battery cooling and deterioration is all a myth that some are using to either discredit the Nissan company or for Nissan to blame battery deterioration on temperature rather than time. If all members recall their past experience, they may see my point.

Except for those hot climates where daily temperatures are over 100 degrees, the reported posts on battery temperature are irrelevant. If posters are complaining that their battery temperatures have "spiked" up to 100 or even 112 degrees, their complaints are totally trivial. First, if you are driving in a 70-95 degree ambient temperature (and the car's battery is working hard to propel you at high speed), what is so terrible if the battery temperature goes up to 100-110 degrees? That temperature is just slightly above your normal body temperature. If you touch something with that temperature, then you would hardly perceive that it is hot at all... Maybe a bit warm. I cannot imagine that that temperature would DEGRADE any rechargeable battery. Man, my Samsung cell phone gets so hot that it burns in my pocket at times, and it still continues to work fine for years. In my opinion, battery temps of 120-140 degrees would be more damaging than at 100 degrees.

Second, this is my theory of what is happening. I have used rechargeable batteries since the 1970s in all types of products, and the following NEVER changes. Rechargeable batteries do an amazing job of holding and giving out electricity, with many cycles of discharge and charging. Truth is that rechargeable batteries have still not progressed that much. The lifetime of a cordless drill battery (my closest comparable battery to EV batteries) only last 2-4 years before they do not hold a charge.

So, it is my "conspiracy theory" belief that (except the crazy people that buy Leafs and live in desert and tropical climates) all battery deterioration that people report is a NORMAL expression of the battery's normal lifetime. Think of it, my battery has over 1500 charging cycles and is still (for now) strong. THAT is amazing. Of course, Nissan would never "to your face" tell you that their batteries are strong for only 2-3 years and go downhill from there. No one would ever consciously buy their cars then. SO.... It is easier to blame high battery temperatures (caused by users), which give us users the "fantasy" that we can extend the life of our cars with careful use. Its like the TV commercial fantasy that if you eat probiotics and organic food, you will live to 120...

I, personally, voluntarily took the plunge with my Leaf and hope that by the time my battery needs to be excised, batteries will either last longer or will have greater capacity. I really think that Leaf owners should consider themselves as trailblazers who are testing out the future technology of our planet. They should not be considering themselves as "discriminating consumers" that EXPECT all their products should work perfectly, like their continued fantasy that their world should be also perfect.

Nissan has repeatedly offered the information that "the battery is expected to last for the life of the car and should retain typically 80% of the original capacity after 8 years or 100,000 mile of operation." They said that about the original Leaf, the revised 24KWH model, and even put it in writing for the 2016 and newer 30KWH models. See the 100,00 mile battery warranty for more info. Nowhere has Nissan ever stated that the car is unsuitable for hot climates or that it should only be considered for light to moderate use.

No one has ever proved why the battery deteriorates in warm climates, only that it does. No has ever proved that the excessive loss of capacity is limited to early 2016 models ( bad batch theory). Most of the 2016 and 2017 models simply haven't been on the road long enough to draw any meaningful conclusions. DCFC doesn't seem to have any meaningful correlation nor does high numbers of L2 charges.

If the manufacturer warrants the drivetrain and battery for 100,000 miles why shouldn't I believe them? Why should I expect to be a guinea pig for their manufacturing processes? I don't think that it is unreasonable to expect any car to last for 150,000 miles and a well built car to last for 200,000+ miles with reasonable maintenance. Average life expectancy for cars in California is about 15 years. Do you really believe that the average Leaf is going to come close to that without a couple of battery changes?
2016 SV
Jamul, CA
San Diego East County

LeftieBiker
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Location: Upstate New York, US

Re: Battery temp management for new leaf

Sun Oct 22, 2017 8:57 pm

I wonder how Powersurge would explain the sudden jump in pack longevity that occurred in April of 2013...? Before then it was ""normal" for packs to lose several capacity bars over just three years in all but the very coolest climates. Then, starting in 4/2013, bars were retained in all but the hottest climates, with first bar loss yet to occur in many of these cars (including mine), and with others losing just one bar about now. Perhaps some sort of mass migration of Leaf drivers Northward in April of 2013?
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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