Capacity Loss on 2011-2012 LEAFs

[cwerdna]

I watched discussion with Goshen recorded in NYC on June 12, 2012,he said that he care so much about us, so we will see....

It's Carlos Ghosn. The latter rhymes w/phone. There's no sh sound, so it's not Goshen.

 

[Herm]

I've read a lot of posts where folks want thermal management, a.k.a. battery cooling. I'm not so sure. I recall that the Tesla Roadster used close to a kilowatt of power when plugged-in in order to cool the battery pack.

That was early in the Roadster history, they fixed that but I'm not sure how much it consumes now.. the Volt consumes 200wH to keep the pack cool, thats not a lot.

 

[edatoakrun]

Welcome to the Anthropocene:

•The January-June period was the warmest first half of any year on record for the contiguous United States. The national temperature of 52.9°F was 4.5°F above the 20th century average. Most of the contiguous U.S. was record and near-record warm for the six-month period, except the Pacific Northwest...

U.S. climate highlights — 12-month period (July 2011-June 2012)
•The July 2011-June 2012 period was the warmest 12-month period of any 12-months on record for the contiguous U.S., narrowly surpassing the record broken last month for the June 2011-May 2012 period by 0.05°F. The nationally-averaged temperature of 56.0°F was 3.2°F above the long term average. Every state across the contiguous U.S. had warmer than average temperatures for the period, except Washington, which was near normal.
•During the June 2011-June 2012 period, each of the 13 consecutive months ranked among the warmest third of their historical distribution for the first time in the 1895-present record. The odds of this occurring randomly is 1 in 1,594,323.

http://www.ncdc.noaa.gov/sotc/" onclick="window.open(this.href);return false;

I wonder (and maybe Nissan does, also) how different the number of capacity bar loss reports would have been, had we had more "normal" temperatures over the 18 months since LEAF deliveries began.

Last summer was probably the coolest I've ever seen in Shasta County. The first real heat wave of the summer came late this year, but it's supposed to hit ~110F tomorrow in Redding, and ~104 up here at 2,000 ft. So, If I drive, I'll see 7 temp bars tomorrow, for the first time this year.

 

[abasile]

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.

As of today, this is basically what I'm doing. I live in a relatively cool location (SoCal mountains at 6100') and started a job earlier this year that involves a commute to the valley below, which is usually 15-20 degrees F warmer. My policy is that if the predicted high temp in the Valley is close to 100 F or higher, I will take the family's Prius to work instead of the Leaf, and let other family members use the Leaf for shorter trips around the mountains. Heat isn't beneficial for the NiMH pack in the Prius either, but I suspect it is less sensitive to heat than the Leaf's battery. And it's much cheaper to replace. I do wonder about the Li-ion batteries in the Prius V and PiP, though, and I've been seeing multiple Prius Vs at work, baking in the sun.

Today it was sad to lose my "100% petroleum free" commuting record, though. Later this week it's expected to cool some, and I can park in shade at work, so I'll be taking the Leaf again.

 

[Stoaty]

As of today, this is basically what I'm doing. I live in a relatively cool location (SoCal mountains at 6100') and started a job earlier this year that involves a commute to the valley below, which is usually 15-20 degrees F warmer. My policy is that if the predicted high temp in the Valley is close to 100 F or higher, I will take the family's Prius to work instead of the Leaf, and let other family members use the Leaf for shorter trips around the mountains.

Today it was sad to lose my "100% petroleum free" commuting record, though. Later this week it's expected to cool some, and I can park in shade at work, so I'll be taking the Leaf again.

Yes, I felt very odd driving my Camry to work 2 days in a row, but with temperatures at 100 degrees F in the valley (but only 70-75 degrees in my parking garage) I can't justify subjecting my Leaf to those temperatures until Nissan releases more information about the battery capacity loss curve of the Leaf as a function of temperature. I am especially sad that I feel the need to take this step due to the continuing lack of disclosure from Nissan. We're on our own here. For anyone who asks about the Leaf, I now will be adding the information that heat appears to be very bad for the battery pack and that those who live in hot areas (e.g., San Fernando Valley) should probably purchase a Volt instead, or wait for an EV with TMS. I hate to jump to conclusions like this without full data, but the precautionary principle means that I need to make a decision to avoid risk when the data that is available suggests the possibility of a significant problem.

 

[EdmondLeaf]

abasile, Stoaty I am 100% with you, this is so sad that there is no communication from Nissan. I am completely Ok that I won't be able to use Leaf for about 4 mo a year during hot weather but we need info from Nissan to guide us how to protect our battery. I believe there is mutual interest here, "normal" degradation is not good enough here. I still believe that Nissan technology is better than normal for cell phones and laptops, however Nissan force us to believe that is normal like any other battery in this group. Same as others, I can't recommend Leaf to other people because I am not sure what future hold and I am not sure if Nissan is doing anything to fix problem of fast battery degradation as a result of high temp. A in the past, I want to be proud Leaf owner, again, and recommend car to others, but communication from Nissan is really needed at this time.

 

[GaslessInSeattle]

...
I think the FFE, which like the Volt has battery TMS, is the real head-to-head competitor for the LEAF.
...

I've been looking, and sadly, the FFE is a nice car but it lacks quick charging and has substantially less leg room and much less trunk space. without a QC port, it's a no go for us, period!

oddly, the next choice is the base Tesla S, which is a jump but you get a lot more with that jump. with the ridiculous response from Nissan over this range loss issue, we've actually considered selling the Leaf and our other car and buying an S.

Nissan has, IMHO, really blown this. depending on how they deal with this going forward, we may never buy another Nissan... it's really quite sad and mind boggling to me. Someone needs to interrupt the board meeting, tap Carlos on the should and whisper "we have a problem" in his ear... the guy is just too smart to let so many years of investment go up in smoke by not standing behind their product.

 

[DaveEV]

Heat isn't beneficial for the NiMH pack in the Prius either, but I suspect it is less sensitive to heat than the Leaf's battery. And it's much cheaper to replace.

Well, the main benefit is that reduced capacity in a hybrid doesn't reduce functionality much.

I do wonder about the Li-ion batteries in the Prius V and PiP, though, and I've been seeing multiple Prius Vs at work, baking in the sun.

Prius V in the USA uses NiMH, not Lithium. The PiP is typically going to be fully discharged (around 20% SOC) during the heat of the day unless they charge it right when they get to work, so at least the battery will be close to optimum SOC for storage. In California, anyway, you have the benefit of a 10-year 150k mi warranty on AT-PZEV hybrids, though the warranty for the PiP doesn't cover capacity loss, same as Nissan. I think technically it could be reduced to the functionality of a regular Prius but as long as it still gets ~50mpg it's OK. The PiP does have the benefit of at least air cooling from the cabin, though that doesn't help when the car is baking in the sun.

 

[cwerdna]

Well, from what we've observed on Priuschat, hot climates/heat (and hills) don't seem good for their NiMH batteries either. There seems to be a correlation between one of those or both those conditions and earlier HV battery failure.

http://priuschat.com/threads/hybrid-battery-replacement-options.111494/" onclick="window.open(this.href);return false; was a great post as background info.

 

[TickTock]

oddly, the next choice is the base Tesla S, which is a jump but you get a lot more with that jump. with the ridiculous response from Nissan over this range loss issue, we've actually considered selling the Leaf and our other car and buying an S.

Us too. The S is a LOT more than I ever thought I'd spend on a car, but the Volt is not an option (if I wanted a hybrid, I'd already own a Prius). For the record, Nissan HAS responded to this (saying the loss will not continue top drop as precipitously as we are seeing in the first year of ownership and we can expect to still have 80% after 5 years). The problem is we just don't believe them since a few of us are already past that. The only thing that stops me from getting the S is I want to see what happens in the fall. If my capacity recovers then I'm good.

 

[RegGuheert]

The only thing that stops me from getting the S is I want to see what happens in the fall. If my capacity recovers then I'm good.

One thing I am convinced of is that any bars lost this summer beyond the first bar must be permanent loss. Why do I say this? Because no one lost any bars last summer. It is possible that some LEAFs were right on the edge of losing a bar at the end of last summer and then they recovered some over the winter. But the loss of additional bars this summer must entail permanent loss within a one-year period. So cars which have now lost two bars must have at least 6.25% permanent capacity loss and cars which lose a third bar will have at least 12.5% permanent loss, assuming these cars were around last summer.

 

[TickTock]

The only thing that stops me from getting the S is I want to see what happens in the fall. If my capacity recovers then I'm good.

One thing I am convinced of is that any bars lost this summer beyond the first bar must be permanent loss. Why do I say this? Because no one lost any bars last summer. It is possible that some LEAFs were right on the edge of losing a bar at the end of last summer and then they recovered some over the winter. But the loss of additional bars this summer must entail permanent loss within a one-year period. So cars which have now lost two bars must have at least 6.25% permanent capacity loss and cars which lose a third bar will have at least 12.5% permanent loss, assuming these cars were around last summer.

Oh I don't doubt that there is permanent loss. I just want to see how much lower I am versus the same time last year. If I creep back up into the 10-15 range (I was around 12% last year), then maybe 20% is achievable over 5 years.

 

[mkjayakumar]

oddly, the next choice is the base Tesla S,.

George, have you seen any capacity or range loss ? if so how much ? what are your GID numbers if you happen to know ?

 

[SanDust]

We are not going to see a chart of battery life as a function of time and temperature because there isn't such an animal. It's more a function of time, temperature, SOC, and driving habits. Having your Leaf at work when it's 100F with a 60% SOC is probably better from a capacity loss standpoint than leaving it in the garage at 75F with a 100% SOC. More generally you have battery aging from calendar life and cycling on the one hand, and from vehicle conditions like vehicle driving profiles and temperature on the other. It's not ONLY about temperature.

The capacity loss line due to temperature is also kinked. You get faster losses out of the box for the first year or two. However, as you move through time the lines for capacity losses in temperate and hot climates move ever further apart. There will be a larger difference in capacity at 8 years than at 5. The lack of a TMS system on the Leaf accelerates this process but doesn't create it. You'll have the same widening difference in capacity even if you have a Volt or a Tesla.

I don't see how "saving" the Leaf battery makes any sense if "saving" the Leaf battery causes you to incur other costs. The battery cost is probably smaller than what it costs to maintain and drive a second vehicle. Note that you will also have power losses along with capacity losses. And also note that you have the same power loss issues with ICE vehicles.

 

[EdmondLeaf]

oddly, the next choice is the base Tesla S,.

George, have you seen any capacity or range loss ? if so how much ? what are your GID numbers if you happen to know ?

Trust and confidence equally or maybe even more important than GIDs. This is important for me, and even more important for regular buyer. At the end this is first mass produced EV that should gain sizable market share

 

[mwalsh]

Gids should probably only be one tool in judging battery health. At least for me, because mine have always been all over the place! I combine Gid count with the depletion rate of fuel bars, and the apparent remaining range at the end of the day. Still not paying much attention to the GOM.

 

[DANandNAN]

Because of the limited range I really don't see how it matters whether there's an indicator or not.
...
A 20% hit is something that gets noticed - be it mileage, paycheck, or milkshakes :lol:

People believe what they want to believe. I've used the example of Tesla owners claiming they have experienced no loss of battery capacity when you know that's not the case. Range is a hard thing to measure over time because it's so impacted by your driving habits. As you learn how the techniques your range may be going up even as your battery capacity is going down. Plus lots of people aren't pushing the range so they'd never have a range benchmark to use.

Right, and that's my point. The limited range of the Leaf will make any loss more easily apparent. As you said, a car (Tesla) that can go 250 miles between charges has a lot of variables, but the Leaf's range is much less so the variables will also be less. And, theoretically owners deplete the Leaf's range more often so they'll have more experience with miles observed now v. after a 20% loss.

To further my point, IIRC there was an owner (here?) that said he'd noticed the lack of capacity and logged in to see what's up. He hadn't lost the first bar at that time, just that his/her range was lower.

Range loss more apparent in a Leaf than a Tesla whether there's a capacity gauge or not.

 

[GaslessInSeattle]

Ironically what I have issue with is not the performance of my Leaf(s). We traded up to the 12 and have about 8K miles on it, so I have not and would not expect to see range loss this early and of course we are in a cool climate where the Leaf appears to be performing exceptionally well. My concern is actually more with the market for the leaf and how it will respond to the trend that is building in hot climates, especially in regard to Nissan saying what is going on is both "limited" and "normal". If "gradual" can mean 20+% a year then the warranty is essentially meaningless. It's hard to imagine this leading anywhere else but to a collapse in basic trust and confidence in the Leaf/Nissan, ultimately causing a huge hit to resale value. It's the hit to resale value that has me watching closely and considering selling. For better or worse, I'm one of those folks who is not buying for the long term but rather plans to hop up the technology ladder a few more times before settling in to an EV for the long haul and that requires seeing each purchase as an investment. I like to think I use my purchasing power to help promote what I believe in and even benefit the used market, but in order to stay in the game I have to make investments wisely. given the tax credit, savings in gas, trade ups can be remarkably affordable as long as the car retains value well. Nissan really needs to come up with a confidence boosting response soon, or they will lose at least one more valuable Leaf advocate to a whole new kind of range anxiety.

oddly, the next choice is the base Tesla S,.

George, have you seen any capacity or range loss ? if so how much ? what are your GID numbers if you happen to know ?

Trust and confidence equally or maybe even more important than GIDs. This is important for me, and even more important for regular buyer. At the end this is first mass produced EV that should gain sizable market share

 

[turbo2ltr]

I did a trip I normally do (but haven't in several months). I used to do home->work->Lunch->work->45-50mile trip-> home in one charge and I usually had 3 maybe 4 bars left.

I had about 7 miles of highway driving (slightly uphill) left and deep into 3 bars when I chickened out and took the side streets. I ended up with 2 bars left. (keep in mind I'm still on the original firmware so zero bars is zero miles). In hind sight, I probably could have made it if I stayed on the highway, but it would have been close. It's also confusing since these "adjusted" bars do not represent the same capacity the old full capacity bars did...

But my point is, by my guesstimate using what I remember I used to have left after this trip, I've lost 12-15 miles of highway range....roughly 2 bars, 16%, 4kw.. (my average is about 3.9 mi/kWh, so )

 

[GRA]

<snip>

Nissan has, IMHO, really blown this. depending on how they deal with this going forward, we may never buy another Nissan... it's really quite sad and mind boggling to me. Someone needs to interrupt the board meeting, tap Carlos on the should and whisper "we have a problem" in his ear... the guy is just too smart to let so many years of investment go up in smoke by not standing behind their product.

I find Nissan's behavior so far incomprehensible; it's like watching someone commit suicide in slow motion. George, someone needs to write a letter, open or otherwise, to the head of Nissan North America if not Carlos Ghosn himself. I'd started writing one making the same points as you, that Nissan was destroying all the goodwill (especially from new customers) they'd earned by building the first mass market BEV, as well as the fact that once this info moves from enthusiast forums to the mainstream media, anti-EV bloggers and radio ranters, it won't just be the Leaf or even Nissan that will be engulfed by the fallout - all EVs will suffer, because none of the above or the general public is likely to draw fine distinctions between battery chemistry or cars with/without TMS.

I decided not to write the letter. As I'm an EV enthusiast in general rather than a Leaf owner, I thought it might carry a bit more weight coming from someone who is.

I've been amazed that we haven't been seeing this mentioned outside of 'our' forums, but it's inevitable that it will be, and perhaps until it does Nissan will continue to stonewall. So, if a Leaf owner were to write such a letter, you might include a time limit (August 1st, say). If someone senior from Nissan hasn't got up on his/her hind legs by that point and publicly acknowledged that there is a problem and that, even if Nissan hasn't yet decided how to handle it, they guarantee that will stand behind their cars and their customers, then the letter will be sent to Consumer Reports, car mags and various mainstream media outlets.

George, I happen to think you'd be ideal for this, but there are several others here who are capable, informed enthusiasts who want nothing but the best for the car and Nissan, and don't want to see them throw away everything they've gained. Someone needs to give Nissan a wake-up call, because they seem to be asleep with the plane on auto-pilot; it's just a matter of time before they run out of fuel and crash. If we're lucky, they won't take all other EVs with them.