Capacity Loss on 2011-2012 LEAFs

[LEAFer]

In response to SanDust:

Regarding use of the generic 18650 term: this is a mechanical spec (18mm x 65 mm). It tells you nothing of the chemistry.

Roadster ESS (battery pack): is indeed quite similar to laptop batteries. But that's where the comparison ends.

1. A laptop has *NO* (read: ZERO) TMS; the Roadster has a VERY good, expensive and efficient TMS.
2. Most (older) laptops have zero or very POOR ( & cheap ) BMS. Those are (most likely) the laptops you are refering to and base your conclusions on regarding poor long life experience of their 18650s. The Roadster has a very sophisticated (expensive) BMS.
3. Tesla Motors, during its stealth mode (2003-2006) -- and beyond -- carefully studied the batteries they ended up with in the Roadster. They worked closely with Panasonic on the chemistry to improve it for the automotive application.

All of the above applies to the Model S, plus much more research and significant improvements and changes to the Tesla implemented chemistry, BMS and TMS.

The data presented to you more than once in this thread ... speaks for itself.

 

[leafwing]

20. Leafwing - July 05, 2012, 13.5k /15 months, Plano, TX.

 

[GerryAZ]

Please add me to the 11 bar club. My actual measured capacity loss is only 7% but my initial capacity was low so I have apparently reached the 15% threshold of an ideal battery. I will provide more information when I have time this weekend.

Gerry

 

[cwerdna]

Updated Leafwing's info. Added GerryAZ. I think in the future, it'd be helpful for everyone to start off their updated list w/what they changed.

1. Azdre & Opossum - April 26, 2012. 16.6K miles/13 months ownership. Phoenix (2nd bar loss reported 6/14/2012 @~19K miles)
2. bturner - May 12, 2012. 13.6K/12 months. Phoenix
3. turbo2ltr - May 18, 2012. 13K/15 months. Phoenix (2nd bar loss reported 6/29/2012)
4. TickTock - May 20, 2012. 14K/12 months Phoenix
5. Volusiano - May 20, 2012. 16.5K/12 months. Phoenix
6. Mark13 - May 22, 2012. 15.7K/12 months. Phoenix (2nd bar loss reported 7/1/2012)
7. Leafkabob - May 26, 2012. 9.5K/12 months. Phoenix
8. Cyellen - June 7, 2012. 10.2K/ 14 months. Phoenix
9. RickS - June 10, 2012. 11.3K/13 months. Phoenix
10. Pipcecil - June 17, 2012. 20.2K/12 months. Dallas, Texas
11. Phxsmiley - June 17, 2012. 13.7K/10 months. Phoenix
12. AZknauer - June 17, 2012. 9.2K/13.5 months. Phoenix
13. Myleaf - June 19, 2012. 13.3K/14 months. Phoenix
14. johndoe74 - June 5, 2012. 13.5K/ 9 months. Phoenix
15. Matt Ferris - June 20, 2012. 15K/ 12 months. Dallas, Texas
16. Shrink - June 21, 2012. 10.2K/ 10.5 months. Phoenix (sold that Leaf, replaced w/leased '12 Leaf)
17. ravi100 - June 24, 2012. 13.1K/ 13.5 months. Southlake, Texas (no longer has Leaf)
18. ev4me - approx. June 1, 2012. 7K/ 15 mos. Phoenix (Dropped 2 bars)
19. jspearman - June 28, 2012, ?/10.5 months. Phoenix
20. Leafwing - July 05, 2012, 13.5K/15 months, Plano, TX.
21. GerryAZ - July 05, 2012, ?/?, Phoenix

Not reported by owner, but by others:
1. Opossum has reported of two cars in Phoenix that have lost 2 bars.
2. Leafkabob reported a street encounter with a Leaf owner who stated he lost a bar after about a year.
3. Skywagon approx. May, 2012. Phoenix (supposedly no longer has Leaf)

 

[EdmondLeaf]

Leafwing sorry to hear bad news fro TX again, not all cars start with same capacity and that is huge factor, so that is why mileage not matter much as well as the way you charge the car. Unfortunately we also eliminated heating up during the day (ravi100 car spend most of the day in garage during summer) and heating up while driving because air movement under the car so temp is close to ambient while driving. I was told that is not hot in here even temp this year higher in OKC than DFW but this does not matter too. I strongly believe that sizable damage is done if battery temp stay in high 80F. It is very hard to cool battery especially if temp at 11pm still 88F but this is just beginning of summer.

GerryAZ amount of energy used to recharge from 0 to 100 is a very good indication of battery health. I predicted that you have 230 and feared that you maybe on edge of top capacity bar

We need to have an opotion to cool battery and this is not only AZ problem

 

[HXGuy]

Pretty crazy to see this unfold. I was so close to pulling the trigger on a Leaf lease a little over a month ago but am thankful now that I didn't. Even though it would have been a lease, I still would want to have the full battery capacity I'm supposed to.

I wonder how long Nissan will continue to ignore this and say it's "normal". What happens if/when people lose 3 bars? 4 bars? Is that still normal? What about 5...6? Basically at what point will they not consider it normal anymore.

 

[TonyWilliams]

Basically at what point will they not consider it normal anymore.

When the legal department says they can. In others words, they will never admit what they already carefully worded to not be guilty of. They SPECIFICALLY said capacity wasn't covered.

Public perception is another thing. Having some cars in extremely inhospitable places have heat related problems might not get the viral attention that cars blowing up do.

I can tell you that the engineers who do the testing in Phoenix "don't think there is a problem". And that is what Nissan will go with. How they reach that thought is anybody's guess, and I have my theories how.

The bottom line. Nissan will pull the plug on LEAF before admitting guilt. When cars reach 70%, 50%, etc, but can still be driven done the road, and accelerate normally, that degradation will be NORMAL. What period of time won't matter because it's "gradual".

The only thing they will cover will be a battery with a bad cell. Once they come out with the next battery technology, which they are working on now, they won't have time, desire, money, etc, to "fix" what isn't broken in hot climates.

My car will very soon lose that first capacity bar in moderate temp San Diego. I got another LEAF with a lease, so I'm much happier with that. I'm very happy with the car overall, and accellerated battery degradation (beyond what I find normal based on Tesla Roadster performance in hot or cold climates) is only one issue for me and my LEAF. The short range is a much bigger issue, and I do not expect a change for that from Nissan or BMW in this market niche.

It looks like the Tesla Roadsters are doing very, and I expect the same from Model S. Even BMW is showing weaknesses in their design, as evidenced at the Laguna Seca event on Sunday with thermal power limiting (and active battery temp control). I think my next car will be a Tesla.

 

[Stoaty]

This thread has crystallized my thinking about temperature and the Leaf battery pack. I live near the coast where it is cool, but work in the San Fernando Valley, which can be fairly hot for several months in the summer. I am going to implement my own TMS: when the predicted high where I work is going to be greater than 95 degrees, I will take my ICE car to work instead. That will be about 7 weeks a year, minus 2 of those weeks I will probably be on vacation, so 5 weeks a year I won't take the Leaf to work. While I hate taking the ICE vehicle on principle, this should be cheap insurance and slow down any capacity loss by avoiding the worst temperature extremes (apologies to Phoenix folks--those temperature "extremes" must sound pretty tame to you). Unfortunately, this TMS is not available for most people.

 

[Volusiano]

The bottom line. Nissan will pull the plug on LEAF before admitting guilt.

Nissan doesn't have to pull the plug on the LEAF. Public perception will do it for them. Look at the already sagging sales. Look at posts on this forum already popping up from potential buyers who are pulling the plugs on their Leaf purchase or even lease decisions.

 

[SanDust]

Regarding use of the generic 18650 term: this is a mechanical spec (18mm x 65 mm). It tells you nothing of the chemistry.

Roadster ESS (battery pack): is indeed quite similar to laptop batteries. But that's where the comparison ends.

1. A laptop has *NO* (read: ZERO) TMS; the Roadster has a VERY good, expensive and efficient TMS.
2. Most (older) laptops have zero or very POOR ( & cheap ) BMS. Those are (most likely) the laptops you are refering to and base your conclusions on regarding poor long life experience of their 18650s. The Roadster has a very sophisticated (expensive) BMS.

1. I'm talking specifically about the Panasonic 18650 cells. In fact I'm talking about the NCR-18650A cells.
2. The batteries used in the Roadster aren't "like" laptop cells. They ARE laptop cells.
3. Laptops don't need a TMS because they sit in air conditioned offices not in heat soaked parking lots and they only need to work for a few years.
4. The Roadster cells will degrade very quickly over the first 300 cycles. Heat in AZ will just speed up the degradation. The higher the heat the more accelerated the degradation.

That's the reality. You can choose to believe some random guy who says he charges his pack five times a day and hasn't lost battery capacity because his range hasn't dropped but don't try to pass this off as fact. Rather than wasting time on untrustworthy sources just use Google to find the degradation graph for the Panasonic cells. It will tell you all you need to know.

The Model S won't use these cells. It will use the new NNP cells. These use a lithium nickel cobalt aluminum oxide cathode material with a carbon anode. The cycle life to 80% still sucks but it's much better if you're only shooting for 70%. But even using 70% they still won't last anywhere near as long as you're claiming. Here is what Tesla says about the Model S battery:

How many years will the battery last?
Based on testing, Tesla expects the battery to retain approximately 70% of its initial capacity after seven years or 100,000 miles.

Sound familiar? To me it sounds a lot like what Nissan said about the Leaf battery, only Nissan said eight years not seven years. And what they said may be true ... just not in Arizona or other very hot places.

 

[TonyWilliams]

The bottom line. Nissan will pull the plug on LEAF before admitting guilt.

Nissan doesn't have to pull the plug on the LEAF. Public perception will do it for them. Look at the already sagging sales. Look at posts on this forum already popping up from potential buyers who are pulling the plugs on their Leaf purchase or even lease decisions.

I honestly don't believe that the Joe SixPack buyer knows anything about this issue. It's obvious to me that sales were down before this issue erupted in the cyber world, and is still a non-issue for places that aren't baking hot. That's most of the USA and virtually all of Canada. And Europe. And Japan.

Nissan may pull the plug because of sales, but I do not believe that our tiny niche of LEAF owners complaining on a web forum are going to wag the tail of Nissan or the bulk of future owners. Heck, I know the issues reasonably well, and still got another LEAF. It fits my needs reasonably well for a good price. It's true weaknesses to me, again, are bigger than battery degradation.

Not leasing one seems really short sited to me, except if the range was so borderline that degradation would make it unworkable. But then, the car probably wasn't the best choice to begin with, unless you really wanted an EV.

I sure would not assume that temp controlled cars would automatically be WAY better in Arizona. Probably, but please note that BMW ActiveE's weren't handling Laguna Seca so well, and it was about 70F to 75F.

 

[Herm]

I hope the Leaf battery degradation issues dont tar other electric cars.. every other manufacturer has implemented an active cooling system, even the lowly iMiev.

 

[RegGuheert]

So, at this point do we have any LEAFs in Phoenix over 12 months old with all 12 capacity bars?

 

[SanDust]

I sure would not assume that temp controlled cars would automatically be WAY better in Arizona. Probably, but please note that BMW ActiveE's weren't handling Laguna Seca so well, and it was about 70F to 75F.

A TMS should help a lot in hot climates, assuming it's working. The problem with capacity degradation is that the free lithium ions in the electrolyte move to the anode and form a patina. Once this happens these ions are out of the game, reducing the capacity of the battery. Heat accelerates this process and a TMS will definitely help retard it.

I don't know anything about what you're referring to when you say the BMW ActiveE's were having issues at Laguna Seco, but my guess is that this was more an issue of concentration polarization or the creation of local dead zones where the anode can't supply the lithium fast enough (locally starved functional ions). That would kill performance but wouldn't result in capacity degradation.

 

[tbleakne]

My efforts to limit overnight temperature in my garage have enabled my Leaf to still get down from 6 to 5 temperature bars each the morning, but that will end in a week or two as summer progresses.

I am still thinking a simple wall AC unit in the garage might make sense, at least to take the edge off the hottest days. Prolonging battery life is worth using some energy.
>>>

I would have gladly paid more for a cooling loop for the battery.

Apparently Ford felt their customers would agree, hence the Ford Focus Electric at $40K.

I agree spending some of my excess TOU solar credit on garage AC would be wise. I have been looking at small AC units. I am fortunate that my garage has a window, but I am not sure I can find a unit to fit it. I could also get the stand-alone type that exhausts heat through a hose.

I don't believe the cost of the Ford Focus EV is relevant. A basic cooling loop that would get a hot battery back to ambient in the evening should have minimal impact on cost for the LEAF, possibly comparable with the cold-weather package which is bundled with the 2012 SL model, which I don't need in my climate. If the cost is significant, both the cold-weather and "hot-weather" packages could be independent options. Of course having more options has its own manufacturing inefficiencies.

 

[DaveEV]

I agree spending some of my excess TOU solar credit on garage AC would be wise. I have been looking at small AC units. I am fortunate that my garage has a window, but I am not sure I can find a unit to fit it. I could also get the stand-alone type that exhausts heat through a hose.

Is your garage insulated? Not really worth trying to cool it if it isn't as it will be a huge energy sink.

Window-type AC units are typically horribly inefficient - even the Energy Star rated units are not all that great. Portable type-units are generally worse. You really want a mini-split type system which can have SEER ratings in well above 20 and close to 30. They are also typically very quiet, but they do cost quite a bit more than a window unit.

A more economical solution where it generally cools off enough at night is to use a simple fan. Panasonic makes a great line of super-efficient fans (WhisperGreen) which can move over 20 CFM/watt - super efficient!

 

[opossum]

Some are advocating leasing over buying in hot climates, based on this discussion, but I for one would not even recommend leasing a Leaf at this point! All Nissan-rage aside (I've got a lot of it now!), there's still an objective reason. Put simply, we're still in the first half of this game! Many of us slid through the last 3 seasons of 2011 with no issues. Now, in just 6 months or so, capacity is plummeting. There are no Certified Leaf Technicians or Certified Nissan Engineers champing at the bit to give us a big halftime speech and slap a proper thermal management system on the car with athletic tape. So what happens this July and August? Even if you leased, is 70% capacity going to be good enough for the last 2 years of your lease? A few of us are at that capacity right now. What about if/when it drops to 60%? Oh, we just had a few 115 degree days in Phoenix. That's normal. Now your capacity is 50%. Oh, you fast charged? Get ready for 40%...

As for whether we are the tail wagging the dog or just venting on this forum for our own cathartic reasons, I'm not sure yet. True, in most 'normal' car buying situations, a very small percentage of people are likely to check some hobbyist forum for solid user reviews and help on deciding whether to buy a car. At best, they may check the Consumer Reports or Motor Trend rankings and stories. But I don't think there's any denying that EVs attract some very specific types. I don't have any hard demographic numbers, but my experience over the last few decades has been that EV owners, on average, tend to be more educated, more curious, and more tech-savvy. Add to that the fact that buying a production EV is a HUGE departure from buying a 'normal' car. Most radical, big-money purchases are probably going to be backed up with some research. I don't know many people who would drop this much coin on something radically different without at least some modest research. Given Nissan's low sales numbers, even a small number of people who check this forum or Google for "Nissan Leaf issues" could represent a statistically significant hit to Nissan's numbers.

Until Nissan reverses its course of outright denial and declares what they are doing to rectify matters, personally I'm hoping this IS impacting their bottom line... and may a swarm of 10,000 fleas infest the crotch of Carlos Ghosn!

 

[Train]

I honestly don't believe that the Joe SixPack buyer knows anything about this issue. It's obvious to me that sales were down before this issue erupted in the cyber world, and is still a non-issue for places that aren't baking hot. That's most of the USA and virtually all of Canada. And Europe. And Japan.

I agree 100% with this.

Not leasing one seems really short sited to me, except if the range was so borderline that degradation would make it unworkable. But then, the car probably wasn't the best choice to begin with, unless you really wanted an EV.

Again, yes. I said this over a year ago quite a few times that leasing this car was, in my opinion, a far better way to finance because of the new technology and unknowns.

 

[RegGuheert]

... and may a swarm of 10,000 fleas infest the crotch of Carlos Ghosn!

Well, that's not very nice! But I do admit laughing out loud when I read it! :lol:

 

[KJD]

Again, yes. I said this over a year ago quite a few times that leasing this car was, in my opinion, a far better way to finance because of the new technology and unknowns.

Train, What kind of car do you drive ?