I loss another battery capacity bar

In my Leaf, the last time I entered turtle the power limit started right before turtle (1-2 gids). It would be a interesting test that people with lost capacity bars check at what gid value the power bubbles start to disappear.

8 turtle
10 power circles

Volusiano said:

JRP3 said:

Eventually if the LEAF keeps dropping battery capacity it won't be able to deliver it's maximum power, and I think Nissan does guarantee that the pack can put out a certain amount of power. You might be better off just driving your pack into the ground in the heat and forcing Nissan to give you a replacement at some point. If you avoid driving the car you may just extend the pack life past the warranty period.

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Good logic, but I'm not so sure that there's a correlation between lower capacity and lower battery power. That's why Nissan is willing to warranty batter power output but is not willing to warranty capacity.

Does anybody have hard evidence that loss of capacity will eventually cause loss of power?

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I would think it has to. Power output is a factor of C rating of the cells. Just for example let's use a 100 amp hour cell rated at 3C, which is 300 amps. If that 100 amp hour cell has lost 30% of it's capacity it's now at 70 amp hours of capacity, so 3C is now only 210 amps. Or to put out the original 300 amps it has to do it at 4.29C which will cause more voltage sag. You might not notice it until you demand maximum power but at some point diminished capacity has to result in diminished power output. Also the increasing relative C rate demands will probably further speed capacity loss since the cells will be working harder all the time. People might try some 0-60 runs and compare times to newer packs with full capacity.

I would have doubts Nissan would be giving away any batteries until they are really shot. Even if there was a warranty adjustment I assume it would be prorated. Just can't see Nissan putting you back to 100% 3 to 5 years into ownership for free.

JRP3 said:

Volusiano said:

JRP3 said:

Eventually if the LEAF keeps dropping battery capacity it won't be able to deliver it's maximum power, and I think Nissan does guarantee that the pack can put out a certain amount of power. You might be better off just driving your pack into the ground in the heat and forcing Nissan to give you a replacement at some point. If you avoid driving the car you may just extend the pack life past the warranty period.

Click to expand...

Good logic, but I'm not so sure that there's a correlation between lower capacity and lower battery power. That's why Nissan is willing to warranty batter power output but is not willing to warranty capacity.

Does anybody have hard evidence that loss of capacity will eventually cause loss of power?

Click to expand...

I would think it has to. Power output is a factor of C rating of the cells. Just for example let's use a 100 amp hour cell rated at 3C, which is 300 amps. If that 100 amp hour cell has lost 30% of it's capacity it's now at 70 amp hours of capacity, so 3C is now only 210 amps. Or to put out the original 300 amps it has to do it at 4.29C which will cause more voltage sag. You might not notice it until you demand maximum power but at some point diminished capacity has to result in diminished power output. Also the increasing relative C rate demands will probably further speed capacity loss since the cells will be working harder all the time. People might try some 0-60 runs and compare times to newer packs with full capacity.

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I think your logic would only work if there are only very few cells packed in the battery pack. But there are plenty enough cells packed in the battery pack that even diminished capacity caused by the drain of normal driving doesn't even diminish the power enough until you get to turtle mode because the current drain requirement from each individual cells is minimal given that there are so many cells in the pack. And even the diminished power in turtle mode may just be an artificial creation of Nissan to protect the cells from being fully drained.

The number of cells is irrelevant. If they all have diminished capacity their ability to deliver power as a whole has to be reduced. The only question is if that reduced power is still enough to meet the demands of the motor. Of course Nissan designed some cushion in the system so that the pack is capable of more power than the motor demands, so even a reduced pack may still provide enough power for the motor.

Now to somewhat contradict my earlier speculation that reduced capacity and greater strain on the cells would speed up battery degradation, I've seen a number of cycle life graphs for cells where capacity loss slowed down dramatically around 70%. If this holds true for Nissan's cells it could be why they are not worried, you may see an accelerated loss in hot climates but that may stabilize around the 70% mark. Their thinking may be if you were OK with 70% of original capacity after 5 years or so you should still be OK with that if it happens after only 2 years or so but holds steady after that. Only time will tell what actually happens.

JRP3, that C power rating is just a rule of thumb for new batteries.. it does not really apply (too much) to old worn out batteries. It is a function of the surface area of the cathodes and the current collecting tabs.. my guess is the battery will deliver its rated hp even when very little capacity is left.

Hmm, interesting, so you don't expect a higher voltage sag from a cell that has dropped from say 40ah original capacity to 30ah capacity when putting out the same amount of current? Isn't capacity loss partially caused by lithium plating on the electrodes, which reduces effective available surface area?

JRP3 said:

The number of cells is irrelevant. If they all have diminished capacity their ability to deliver power as a whole has to be reduced. The only question is if that reduced power is still enough to meet the demands of the motor. Of course Nissan designed some cushion in the system so that the pack is capable of more power than the motor demands, so even a reduced pack may still provide enough power for the motor.

Now to somewhat contradict my earlier speculation that reduced capacity and greater strain on the cells would speed up battery degradation, I've seen a number of cycle life graphs for cells where capacity loss slowed down dramatically around 70%. If this holds true for Nissan's cells it could be why they are not worried, you may see an accelerated loss in hot climates but that may stabilize around the 70% mark. Their thinking may be if you were OK with 70% of original capacity after 5 years or so you should still be OK with that if it happens after only 2 years or so but holds steady after that. Only time will tell what actually happens.

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Which is fine for the people who only need 70%, but lousy for those who were basing their decision to buy on the sole quantification of degradation that Nissan actually mentioned, 80% after 5 years.

JRP3 said:

Now to somewhat contradict my earlier speculation that reduced capacity and greater strain on the cells would speed up battery degradation, I've seen a number of cycle life graphs for cells where capacity loss slowed down dramatically around 70%. If this holds true for Nissan's cells it could be why they are not worried, you may see an accelerated loss in hot climates but that may stabilize around the 70% mark.

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Were these cycle life graphs done at different cell temperatures and still all stabilized around 70%? What about calendar loss graphs at various temperatures?

Their thinking may be if you were OK with 70% of original capacity after 5 years or so you should still be OK with that if it happens after only 2 years or so but holds steady after that.

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That may be their thinking, but it is the lack of disclosure before the sale part that has those in hot areas up in arms.

I assume the graphs were at normal temperatures, so they may not apply in this situation. I was just pointing out that there is some tendency to stabilize around 70% for some batteries. I realize that may also not be good enough for LEAF owners, and with good reason. If they do drop below 80% or so before 5 years Nissan has a big problem.

Randy said:

Although I've read of more than one person whose first symptom is getting 9 bars on an 80% charge. At first it is once in awhile, but then it gets more frequent. A few weeks of that consistently and then they lose the 12th capacity bar...

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I've been randomly recording these accounts of "getting 9 bars when charging to 80%":

http://www.mynissanleaf.com/viewtopic.php?p=208611#p208611" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=205680#p205680" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=206595#p206595" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=210032#p210032" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=211284#p211284" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=211347#p211347" onclick="window.open(this.href);return false;
http://www.mynissanleaf.com/viewtopic.php?p=211563#p211563" onclick="window.open(this.href);return false;

Many of these are in the "80% overnight charge only gets 9 bars" thread.

We'll see when these people start losing the first capacity bar...

Edit: editting to include this very post, 'cause I started getting 9 bars when charging to 80% recently as well . Since June 12, 6 of 18 of my charge events (all to 80%) end with 9 bars.

Well I have lost 3 bars in 3 months. I took it in after I lost the first bar and was told it was normal.
2 weeks later I lost the second bar! I have not lost the third bar last week. Well it is back at the dealer and they are giving me the same BS of normal loss.

3 bars in 3 months does not seem "normal" to me..

NOC8H18 said:

Well I have lost 3 bars in 3 months. I took it in after I lost the first bar and was told it was normal.
2 weeks later I lost the second bar! I have not lost the third bar last week. Well it is back at the dealer and they are giving me the same BS of normal loss.

3 bars in 3 months does not seem "normal" to me..

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Can you provide enough info to fill in the your details at http://www.mynissanleaf.com/viewtopic.php?p=213082#p213082" onclick="window.open(this.href);return false;?

NOC8H18 said:

Well I have lost 3 bars in 3 months. I took it in after I lost the first bar and was told it was normal.
2 weeks later I lost the second bar! I have not lost the third bar last week. Well it is back at the dealer and they are giving me the same BS of normal loss.

3 bars in 3 months does not seem "normal" to me..

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I seriously sympathize! We are probably about 2 weeks away from losing our 3rd bar, and know another who has lost the third bar. Our range loss is about 30%. Make sure to call Nissan corporate ASAP. Apparently the dealers aren't alerting Nissan about the complaints themselves (I'm not sure I believe that, but that's the party line right now). Are you in Phoenix? How many miles are on your car? A bunch of us are meeting in Downtown Phoenix tomorrow at the Roosevelt @ 5:30 if you'd like to join us.

Thanks for the invite and advice.

I also had my brake module die last year and they had it for 5 weeks trying to fix it. The first one was defective and the 2nd one Nissan sent worked. I really love my Leaf just not Nissan. I really thought Nissan would take care of us generation 1 owners for taking the leap and putting faith into the electric vehicle. I might be pushing them on it being a lemon. Maybe as a group, the threat of a class action lawsuit will get their attention.

Here's the story that ran last night on KPHO CBS 5 on LEAF capacity loss. It has both an article and a video at the top.

http://tinyurl.com/c8g9fzj" onclick="window.open(this.href);return false;

Outside of this, we really should "merge" this conversation from this point forward into the other thread that was linked above. Otherwise, we'll all have to start duplicating comments, as a lot of this has been and is being discussed in that huge thread in the Problems section.

opossum said:

Here's the story that ran last night on KPHO CBS 5 on LEAF capacity loss. It has both an article and a video at the top.

http://tinyurl.com/c8g9fzj" onclick="window.open(this.href);return false;

Outside of this, we really should "merge" this conversation from this point forward into the other thread that was linked above. Otherwise, we'll all have to start duplicating comments, as a lot of this has been and is being discussed in that huge thread in the Problems section.

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I wouldn't be too quick to draw conclusions from Nissan's lack of responsiveness, big companies don't respond quickly. Some companies have big cultural bureaucracies. Do we really think Nissan will sit by and do nothing about a two year old Leaf that has only 10 miles of range left?

LTLFTcomposite said:

opossum said:

Here's the story that ran last night on KPHO CBS 5 on LEAF capacity loss. It has both an article and a video at the top.

http://tinyurl.com/c8g9fzj" onclick="window.open(this.href);return false;

Outside of this, we really should "merge" this conversation from this point forward into the other thread that was linked above. Otherwise, we'll all have to start duplicating comments, as a lot of this has been and is being discussed in that huge thread in the Problems section.

Click to expand...

I wouldn't be too quick to draw conclusions from Nissan's lack of responsiveness, big companies don't respond quickly. Some companies have big cultural bureaucracies. Do we really think Nissan will sit by and do nothing about a two year old Leaf that has only 10 miles of range left?

Click to expand...

GM is certainly a company with a big cultural bureaucracy, but Dan Akerson was publicly reassuring owners within a few days of the Volt fire non-issue hitting the mainstream media. At this point, after trying more polite forms of chiding it seems that nothing other than national exposure and/or lawsuits will move Nissan to act.

GRA said:

GM is certainly a company with a big cultural bureaucracy, but Dan Akerson was publicly reassuring owners within a few days of the Volt fire non-issue hitting the mainstream media. At this point, after trying more polite forms of chiding it seems that nothing other than national exposure and/or lawsuits will move Nissan to act.

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not the same thing. GM "knew" there was nothing wrong with the car and the whole thing was nothing more than journalism gone wild. it was nothing more than damage control. they had to mobilize nothing other than a script writer to make their statement... i personally think their response was slow...

Nissan knew what would happen. they had to know. its not an accident that their testing ground is smack dab in the middle of the most affected area.

Nissan has a game plan. a poor one. they are weighing calculated risks with their delay tactics.

as far as a fix? the technology is already proven; provide active temperature control. it aint rocket science. the only thing in the way is logistics. hence the delay...

i think Nissan simply misjudged the time table. they were hoping that early owners in AZ would accept a small loss but the loss ended up coming bigger and faster than they guessed.