I loss another battery capacity bar

[derkraut]

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.

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?

Uh....Where is there a 2yr old Leaf "that has only 10mi of range left"? :? That statement seems like a perfect example of "FUD" to me :roll:

 

[DaveinOlyWA]

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.

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?

Uh....Where is there a 2yr old Leaf "that has only 10mi of range left"? :? That statement seems like a perfect example of "FUD" to me :roll:

it was actually 44 miles of range left

 

[mwalsh]

Uh....Where is there a 2yr old Leaf "that has only 10mi of range left"? :? That statement seems like a perfect example of "FUD" to me :roll:

Until we know just how low the Phoenix cars can go, we'll not know if it's FUD or not. As of right now it looks like prophesy to me. But then I always was a "glass shattered and contents spilled" kind of guy.

 

[tbleakne]

I don't know if this has been discussed before. I'm curious if anyone has been able to determine if it is just a few cells in the pack that are losing capacity, or all of them. After all, if I understand the battery pack correctly, it could be compared to a chain and the weakest link in the chain determines the chain's total strength.

that would be true since BMS is working with total pack voltage for one parameter and when load is applied, weaker cell voltage drop will be much higher than a good cell.

No, I believe we have strong evidence that a few bad cells are not the problem.
Here is my analysis:

All cells, both weak and healthy, have the same maximum voltage. Here maximum refers to the maximum set by Nissan for longevity, which is less than the absolute maximum voltage. Weak cells will normally reach their maximum voltage after they have received less charge then healthy cells. The BMS will stop the charge whenever the first cell reaches its maximum voltage, leaving the healthy cells at a lower voltage, less than their maximum.

This battery pack state, if it existed, would have a signature detectable by the Gid meter. The Gid meter cannot display individual cell voltages, but it can display the total of all 96 cell pairs. If only a few cells are bad, all the others will have a lower voltage, and the total at 100% charge will be measurably less. In response to my queries, no one has reported this drop in total voltage at 100%. Until someone does report such a drop, this evidence suggests all cells are deteriorating together.

 

[JRP3]

All cells, both weak and healthy, have the same maximum voltage. Here maximum refers to the maximum set by Nissan for longevity, which is less than the absolute maximum voltage. Weak cells will normally reach their maximum voltage after they have received less charge then healthy cells. The BMS will stop the charge whenever the first cell reaches its maximum voltage, leaving the healthy cells at a lower voltage, less than their maximum.

Will it, or will it shunt the excess charge on the lower capacity cells when they hit the high voltage mark allowing the other cells to continue charging and hit the high voltage mark? This is a top balancing scheme, what you describe is a bottom balanced scheme.

 

[opossum]

No, I believe we have strong evidence that a few bad cells are not the problem.

The cell tests Nissan techs have done on our car (3 times) would support this. They read back cell voltages from the car and determine whether there are bad cells based on the spread between the highest cell voltage and lowest cell voltage. The tech said the threshold for pass/fail was 50 mV from max voltage to min voltage. Our car, with 2 lost capacity bars, has "passed" this test each time. We have taken it in at both a very high SOC and a very, very low SOC. I just don't know whether the values they read are with the cells under load or not. And if they are simply read from the car, I have no idea whether it is current data or recorded from a specific SOC in the recent past.

There was talk that they wanted to get one of the Phoenix cars with 3 lost capacity bars into the shop, pull the pack, and measure the cells first-hand. I believe the car is in the shop right now.

mason

 

[mark13]

I did not realize anyone had last 3 bars yet but now it looks like several have..We need to do something here as a protest to Nissan..

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..

 

[mark13]

Wow channel 5 did a story on this...Great news for us..

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.

 

[PatricioEV]

There was talk that they wanted to get one of the Phoenix cars with 3 lost capacity bars into the shop, pull the pack, and measure the cells first-hand. I believe the car is in the shop right now.

mason

If so, then it appears that Nissan is responding to this issue.

 

[DaveEV]

All cells, both weak and healthy, have the same maximum voltage. Here maximum refers to the maximum set by Nissan for longevity, which is less than the absolute maximum voltage. Weak cells will normally reach their maximum voltage after they have received less charge then healthy cells. The BMS will stop the charge whenever the first cell reaches its maximum voltage, leaving the healthy cells at a lower voltage, less than their maximum.

Will it, or will it shunt the excess charge on the lower capacity cells when they hit the high voltage mark allowing the other cells to continue charging and hit the high voltage mark? This is a top balancing scheme, what you describe is a bottom balanced scheme.

Exactly - the pack is top-balanced, so at full charge the pack voltage should always be the same as long as the pack is balanced.

Now, measuring voltage at say LBW, VLBW and turtle may show some variation. Packs with a weak cell-pair will have higher voltage than normal.

 

[JRP3]

Shouldn't that be lower voltage than normal at a low SOC? Lower capacity cells will be closer to empty first, showing lower voltage.

 

[DaveEV]

Shouldn't that be lower voltage than normal at a low SOC? Lower capacity cells will be closer to empty first, showing lower voltage.

No, because SOC is determined by the capacity of the lowest cell-pair, once that cell-pair hits LBW voltage, you hit LBW regardless of the voltage of the other cell-pairs (which will be much higher thus raising overall pack voltage).

 

[JRP3]

Ok, I see what you mean, the other higher capacity cells keep their voltage higher since they don't discharge to a low SOC while the low cell triggers a low voltage event for that cell pair.

 

[NOC8H18]

Mine is currently at Larry Miller in Mesa with 3 lost bars.
I have refused to take the car back until Nissan calls me.

Any suggestions?

 

[mark13]

Im sorry your battery capacity did not last as long as Nissan indicated that it would..I dont think there is a better way to protest,then to just leave the car there..Keep us updated daily if possible..
I think we all need to get together on this issue..I wish I was part of the news 5 story,I would make sure they know that you just left the car at the dealer out of frustration..

Mine is currently at Larry Miller in Mesa with 3 lost bars.
I have refused to take the car back until Nissan calls me.

Any suggestions?

 

[jspearman]

Mine is currently at Larry Miller in Mesa with 3 lost bars.
I have refused to take the car back until Nissan calls me.

Any suggestions?

Even if you don't want to be on the news, you should definitely get Opossum to connect you with the CBS 5 newscaster. He has her email. Maybe they can try to interview the dealer and ask why no one is willing to give you a straight answer.

I really like the idea of a Leaf sit-in, so bravo.

 

[shrink]

Mine is currently at Larry Miller in Mesa with 3 lost bars.
I have refused to take the car back until Nissan calls me.

Any suggestions?

Swap it with OrientExpress's car!

But first, file a complaint if you have not done so already. Take pictures of your dash with the missing capacity bars and mileage, as well as your service and battery reports. Document your range with real world tests if you can. When Nissan continues to say it's "normal" loss and a not under warranty, share with the press and pursue consumer protection actions, such as Lemon Laws. Get involved and share information with other affected people locally.

 

[pchilds]

I'll give $10K for a 45 mile range Leaf, how much would you OrientExpress?

 

[Herm]

I'll give $10K for a 45 mile range Leaf, how much would you OrientExpress?

It would cost Nissan about $13k for a new battery, plus labor, so its a fair value for a Leaf with a spent battery.. we hope degradation will slow down to normal if taken to a temperate location.

Now we know what the excess battery production in Smyrna will be used for.

 

[scottf200]

TonyW had a nice summary in another thread for those that are not reading all 3+ of them.

We can also look at the $7500 Fed tax credit as an inducement to buy expensive and flaky batteries.

They aren't flaky. The guy in the Seattle area (where they are experiencing historically lower temps, while the rest of the USA bakes) has over 40,000 miles has a VERY strong battery. It's also never seen real heat.

There's nothing wrong with the battery in moderate temps, and moderate use. Which makes the case for battery TMS all the more pressing. Elon Musk (Tesla, SpaceX, PayPal) thought Nissan was crazy to offer the car without TMS. We thought they had magic.

I think Nissan still has a chance to save the day, by offering either a new battery or a different car, to affected owners. Honestly, I doubt they will, however. It will open them up to lawsuits (yes, they no doubt will get them anyway) which makes any logical outcome less likely. When their corporate back is against the wall, they will do the conservative "all is normal" all the way to quiet, Non-Disclosure-Agreement, back door settlement with a few owners. Any class action lawsuit settlement is so many years down the road, as to effectively be a non-event to a huge corporation like Nissan.

All will continue to be "normal" once the small number of "hot cars" have been silenced (by small, I mean that out of 30,000 cars, only a teeny, tiny number of the most vocal and aggressive "hot car" complainers will get an NDA settlement).

That's business, folks. The LEAF will go on much the same, as planned, throughout the world. They may be re-evaluating TMS for a 2015 or later LEAF with entirely new batteries, but the basic formula won't change before then. Car companies don't have that kind of flexibility. Sales may tank because of mainstream bad press (far beyond snippets on local Phoenix TV stations) as they did for Volt with Faux Noose on their *ss. In that scenario, I can foresee a shutdown of the Tennesee plant to LEAF production, which will then only make gas burners. If Ghosen leaves Renault/Nissan, the LEAF will get cancelled in that scenario.

I feel bad for folks who I predict will get stuck with a seriously diminished car. But, I still think its a pretty good car for moderate climates (not too hot or too cold).