Capacity Loss on 2011-2012 LEAFs

Thanks for the update!

opossum said:

The only specific we were given was that our car tested out at 85% capacity remaining, which was 2nd best of the cars they had. The best was supposedly 86%. This makes no sense to us, as it does not agree with our real world range loss from a year ago under similar driving conditions.

Click to expand...

My guess is that they directly tested the capacity of your battery using a special-purpose tester. What's interesting is that they yielded a capacity of 85% while your car is reporting a capacity of 78.75%. This lends credence to the idea that the BMS somehow further restricts access to battery capacity in hot conditions.

RegGuheert said:

Thanks for the update!

opossum said:

The only specific we were given was that our car tested out at 85% capacity remaining, which was 2nd best of the cars they had. The best was supposedly 86%. This makes no sense to us, as it does not agree with our real world range loss from a year ago under similar driving conditions.

Click to expand...

My guess is that they directly tested the capacity of your battery using a special-purpose tester. What's interesting is that they yielded a capacity of 85% while your car is reporting a capacity of 78.75%. This lends credence to the idea that the BMS somehow further restricts access to battery capacity in hot conditions.

Click to expand...

The plot thickens. Curious to see what they tell us in three weeks. I concur that our real-world range is total crap now and wouldn't correspond to a 10 or 15% loss, but perhaps there is a perfectly logical explanation. Anecdotally, my wife's commute is 25 miles (half surface streets, half highway). That trip took 4 bars from the middle of September to around March. Now 7 bars are missing when she returns home. Same exact commute, same driver, same driving style. Extra A/C use would account for a small portion of that, since it's hotter now than it is in September, but September was quite hot this past year, so the difference is probably negligible.

azdre said:

edatoakrun said:

If one of the answers you get, is if you wanted maximum battery life from your LEAF, you should have followed the guidelines for battery care, will you like that answer?

Yes, I'm sure that all questions will be answered, and every LEAF owner will all be completely satisfied with the answers.

Nissan will announce "improvements" to the LEAF, including reduced access to the battery capacity, a battery cooling system requiring plugging into a public L2 whenever you park outside your garage on a warm day, (hey it's all free power, right?) and a "back-up" ICE, for those who cant figure out what the range of their BEV is.

The improved idiot-proof LEAF!

Click to expand...

There is a HUGE difference between maximum battery life and losing 30% driving range in just over a year.

You are 3 months late trying to blame the users of these 48 (reported to the forum) cars for the issues they are seeing. It's been tried, and most of these kind folks quickly realized that there is no apparent correlation to loss of bars and behavior. From what I've seen, there may be a connection between the severity/speed of the loss and usage behavior, but there's no way to tell, and there's no reason to speculate. All of the affected drivers that we personally know (9, I think) have done NOTHING that was said not to do in the warranty book, nor the owners manual, and thus there's no reason to adjust our expectations of the performance of our vehicle. Most of these owners have had EVs in their garages for decades.

What we have done is put in many, many hours trying to alert Nissan to what is obviously an issue in consistently hot climates and to help all owners get what we paid for. You're welcome! :roll:

If only we could idiot-proof the forum.

Click to expand...

+10! Well said!

vrwl said:

Volusiano said:

There's an obvious contradiction here. According to the transcript above, Eric from Nissan said that the normal temperature range is within the blue and red ranges. But on the other hand, you're not supposed to keep the battery at the 120C level for more than 24 hrs. Well, 7 bars is between 98.2C to 122C, so if the temperature bar says 122C is normal, why can't the battery be under warranty at 120C for 24 hrs, if up to 135C (top range of 10 bars) is considered "normal" since it's not in the red?

Segments Degrees C (F)
12 60 (140)
11 57.5 (135.5)
10 55 (131)
9 52.5 (126.5)
8 50 (122)
7 36.8 (98.2)
6 23.5 (74.3)
5 10.3 (50.5)
4 -3 (26.6)
3 -6 (21.2
2 -9 (15.8)
1 -12 (10.4)
0 -15 (5)

Click to expand...

Yes, I had the same thoughts about that... "between the blue and red gauge squares" essentially means we could safely charge our batteries anywhere from 15.8 degrees F to 135.5 degrees F.

Click to expand...

The manual clear states ambient temperature, not battery temperature.

"Do not expose a vehicle to ambient
temperatures above 120F (49C) for
over 24 hours."

Page EV-2 : http://www.nissanusa.com/content/dam/nissan/pdf/techpubs/leaf/2012/2012-leaf-owner-manual.pdf" onclick="window.open(this.href);return false;

The reason for that is the diffrence in temps will cause the pack to cool down. Even at 120F ambient the pack can cool down to 120F which is 7-8 bars.

Smiley just like mine..Losing the first one was not unexpected but losing the 2nd one with-in 40 days made me very upset...Now when I start up the car,the first thing I do is check the capacity bars

phxsmiley said:

Please move me from the 1-bar club to the 2-bar club on the Wiki. Unfortunately, I lost my second bar today, after only 11 months of ownership. Lost the first bar on 6/17 at 13,745 Miles; Lost the second on 8/6 at 15,868 miles. The second bar was lost in under 2 months and 2123 miles.

I'm hoping we get some solution where we get a better battery, somehow. I enjoy driving the car and really like the electric car experience; It's just not acceptable to lose that much capacity in under a year. It is already becoming less of a useful car in our family, as we now have to include in time for charging where we didn't have to before, for some recent trips.

Click to expand...

opossum said:

We got our car back today. It appears as though they resolved the diminishing capacity issue! I took a picture of the dash. Look, they simply tricked the car into thinking it is only 80 degrees today!

Click to expand...

What if they kept your car in a cold room for a week and then measured the capacity. The temp gauge still has not warmed up to ambient temp at your house.

For those who might be interested.
I have started building a add on which in phase one will cool the battery while parked in the garage. It will not interfere with the cars warranty. The device consists of four liquid cooling pads which go between the current battery dust cover and the battery itself. There is a layer of foam insulation between the cool pads and the dust cover and the outside tempature. The cool pads (will not disclose at this time what they are made of) are held in place by the presure of the dust cover bolted back in place. None of the add on is permanentlly mounted to the car. The entire cool pad set can be removed as quickly as it takes to remove the dust cover and put it back. If the cool pads worst to leak, the liquid would flow down and just drip on the garage floor. There is no danger to the battery pack whatsoever. The cool packs are connected in series via two lines to a unit which chills the anifreeze mixture to a chilling 32 degress. The very large mass of the battery pack and the fact that there can't be any cool packs on the top of the battery case will mean that more than likely the system will not be able to cool the pack itself down to 32 degress. In fact the goal is to maintain the battery while connected at 72 degrees. While keeping power consumption as low as possible. One thing in the systems favor is the fact the battery modules are in the battery case very tightly and therefore actually form a single mass which can be cooled from the outside. (We already have a member that has successfully cooled his battery pack down to 72 degrees by using a window AC directing the cool air under the car while the outside tematures where well into the hundreds!) The unit does have a thermostat and if it is luckly enough to get it to the target tempature then it would shut off until needed again. If the system is found capable of bringing the tempature down to the 4 bar mark. Then the idea would be to bring it close to 4 bars and then due to its great mass it would sort of store some of the cold and would warm up slower, therefore shorting the time that the pack is at a higher tempature once disconnected and driven. This is of course if the system works as expected. Currenly the testing system is too large to be placed in the car for having an actual BMS. The plan is to eventually build a small system that can some how be added to the car in a way that does not distract from its function or interfere with the cars warranty. Of course to have the system be a true BMS system then some work would have to be done to have cooling on top of the battery which would cause some questions. But hey what do we have to loose. Even if Nissan is going to commit some research into a BMS when would we see it???

I am writting this to see if successful would any current leaf owners be interested in such a device. If so what would be a fair price for the add on. I myself do not plan on just sitting idle while my $40,000 investment turns into a paper weight!!!!

I am a software engineer by trade and I spent 20 years in the US Air Force with the last few years in an electrical engineer capacity. I believe I can build the deivce as long as I can come up with the needed funds.

Anyway I would love feedback comments and suggestions. Also I welcome questions on the idea. I will post photos of the system as it is being built but will hold some of the exact details confidential at the moment.

This of course is just thinking out loud and the information is provided as is where is and is not intended to suggest anything :>)

KJD said:

opossum said:

We got our car back today. It appears as though they resolved the diminishing capacity issue! I took a picture of the dash. Look, they simply tricked the car into thinking it is only 80 degrees today!

Click to expand...

What if they kept your car in a cold room for a week and then measured the capacity. The temp gauge still has not warmed up to ambient temp at your house.

Click to expand...

The portion you quoted was a joke. Ignore it if you are trying to figure out the state of his battery capacity.

Now if you were joking it came across as flat serious and I apologize for the misunderstanding

phxsmiley said:

Please move me from the 1-bar club to the 2-bar club on the Wiki. Unfortunately, I lost my second bar today, after only 11 months of ownership. Lost the first bar on 6/17 at 13,745 Miles; Lost the second on 8/6 at 15,868 miles. The second bar was lost in under 2 months and 2123 miles.

I'm hoping we get some solution where we get a better battery, somehow. I enjoy driving the car and really like the electric car experience; It's just not acceptable to lose that much capacity in under a year. It is already becoming less of a useful car in our family, as we now have to include in time for charging where we didn't have to before, for some recent trips.

Click to expand...

Added to the 2 Bars Lost wiki table. Sorry to hear the bad news. Hey phxsmiley, can you check the Mfg Date for your car on the metal plate inside the driver's door opening?

TurboFroggy said:

vrwl said:

Volusiano said:

There's an obvious contradiction here. According to the transcript above, Eric from Nissan said that the normal temperature range is within the blue and red ranges. But on the other hand, you're not supposed to keep the battery at the 120C level for more than 24 hrs. Well, 7 bars is between 98.2C to 122C, so if the temperature bar says 122C is normal, why can't the battery be under warranty at 120C for 24 hrs, if up to 135C (top range of 10 bars) is considered "normal" since it's not in the red?

Segments Degrees C (F)
12 60 (140)
11 57.5 (135.5)
10 55 (131)
9 52.5 (126.5)
8 50 (122)
7 36.8 (98.2)
6 23.5 (74.3)
5 10.3 (50.5)
4 -3 (26.6)
3 -6 (21.2
2 -9 (15.8)
1 -12 (10.4)
0 -15 (5)

Click to expand...

Yes, I had the same thoughts about that... "between the blue and red gauge squares" essentially means we could safely charge our batteries anywhere from 15.8 degrees F to 135.5 degrees F.

Click to expand...

The manual clear states ambient temperature, not battery temperature.

"Do not expose a vehicle to ambient
temperatures above 120F (49C) for
over 24 hours."

Page EV-2 : http://www.nissanusa.com/content/dam/nissan/pdf/techpubs/leaf/2012/2012-leaf-owner-manual.pdf" onclick="window.open(this.href);return false;

The reason for that is the diffrence in temps will cause the pack to cool down. Even at 120F ambient the pack can cool down to 120F which is 7-8 bars.

Click to expand...

TurboFroggy, you missed the first part of the conversation submitted by JPWhite. The manual says something completely different from the information provided by Nissan Customer Service.

jspearman said:

RegGuheert said:

Thanks for the update!

opossum said:

The only specific we were given was that our car tested out at 85% capacity remaining, which was 2nd best of the cars they had. The best was supposedly 86%. This makes no sense to us, as it does not agree with our real world range loss from a year ago under similar driving conditions.

Click to expand...

My guess is that they directly tested the capacity of your battery using a special-purpose tester. What's interesting is that they yielded a capacity of 85% while your car is reporting a capacity of 78.75%. This lends credence to the idea that the BMS somehow further restricts access to battery capacity in hot conditions.

Click to expand...

The plot thickens. Curious to see what they tell us in three weeks. I concur that our real-world range is total crap now and wouldn't correspond to a 10 or 15% loss, but perhaps there is a perfectly logical explanation. Anecdotally, my wife's commute is 25 miles (half surface streets, half highway). That trip took 4 bars from the middle of September to around March. Now 7 bars are missing when she returns home. Same exact commute, same driver, same driving style. Extra A/C use would account for a small portion of that, since it's hotter now than it is in September, but September was quite hot this past year, so the difference is probably negligible.

Click to expand...

I'm shocked that they didn't do a driving range to LBW test with our car when they had it. I would think that would demonstrate the impact of this a lot more evident than some test that shows 85%.

I wanted to make a comment regarding my lost capacity bar just a few days ago. Prior to losing the capacity bar(Now have 10 vs. 11), I noticed my temperature bars totaled 6. After losing a capacity bar, my temperature guage now shows 7 bars.

Correct me if I wrong but, it seems the more the batteries are degraded due to heat, the hotter their temperature becomes...Does that mean they are working 'harder', thus are now giving off more heat?

dsh said:

I wanted to make a comment regarding my lost capacity bar just a few days ago. Prior to losing the capacity bar(Now have 10 vs. 11), I noticed my temperature bars totaled 6. After losing a capacity bar, my temperature guage now shows 7 bars.

Correct me if I wrong but, it seems the more the batteries are degraded due to heat, the hotter their temperature becomes...Does that mean they are working 'harder', thus are now giving off more heat?

Click to expand...

My understanding is that yes, as the battery degrades its internal resistance increases = more internal heat generation.

I'm not too confident in Nissan's prediction of a declining rate of degradation. First, because of the aforementioned increase in heat generation which makes a bad situation worse. Second, because an owner trying to maintain the usefulness of the car will begin to use a greater percentage of SOC. Meaning more frequent charges, more charges to 100%, deeper discharges.

In a lab the batteries might show a declining rate of degradation. In the real world people will work them that much harder.

vrwl said:

phxsmiley said:

Please move me from the 1-bar club to the 2-bar club on the Wiki. Unfortunately, I lost my second bar today, after only 11 months of ownership. Lost the first bar on 6/17 at 13,745 Miles; Lost the second on 8/6 at 15,868 miles. The second bar was lost in under 2 months and 2123 miles.

I'm hoping we get some solution where we get a better battery, somehow. I enjoy driving the car and really like the electric car experience; It's just not acceptable to lose that much capacity in under a year. It is already becoming less of a useful car in our family, as we now have to include in time for charging where we didn't have to before, for some recent trips.

Click to expand...

Added to the 2 Bars Lost wiki table. Sorry to hear the bad news. Hey phxsmiley, can you check the Mfg Date for your car on the metal plate inside the driver's door opening?

Click to expand...

The Mfg Date is 7/2011. I know the car didn't sit at the dealer more than a day. Thanks for the Wiki update and the condolences.

opossum said:

The only specific we were given was that our car tested out at 85% capacity remaining, which was 2nd best of the cars they had. The best was supposedly 86%. This makes no sense to us, as it does not agree with our real world range loss from a year ago under similar driving conditions.

Click to expand...

How much range do you suppose you've lost?

Assuming that 21 kWh usable is available when new (from 100% to turtle), 85% capacity remaining would indicate that you have 17.85 kWh usable now. At 4.0 mi/kWh that would represent a total range of 84 miles when new and now 71.4 miles.

But keep in mind that LBW appears to occur at the same point regardless of overall capacity loss - 49 GIDs or about 3.4 kWh before turtle.

Since one's "range anxiety" factor doesn't change - you still probably start looking for a charging station at LBW and avoid going below that if possible.

That means that your "safe" capacity has gone from 17.6 kWh to 14.45 kWh - a reduction in "safe" range closer to 18% than the indicated 15% - or 70 miles down to 58 miles at 4.0 mi/kWh.

This is worse if you normally charge to "80%" which is about 17.3 kWh usable before turtle when new and 14.7 kWh after 15% degradation.

Now your "safe" usable capacity has gone from 13.9 kWh to 11.3 kWh - at 4.0 mi/kWh that's 56 miles down to 45 miles.

That also means that drives that you used to make at 80% without issue - you now have no choice but to charge to 100%. When new your 80% "safe" range was 58 miles - after 1 year your 100% "safe" range is 56 miles.

Of course - in addition to this, the BMS could be doing something else weird which is giving the appearance of a more significant reduction in range. You wouldn't be the first to claim that.

Completely unacceptable after 1 year.

azdre said:

I'm shocked that they didn't do a driving range to LBW test with our car when they had it. I would think that would demonstrate the impact of this a lot more evident than some test that shows 85%.

Click to expand...

I'm not. A properly instrumented bench test could be set up and repeated multiple times in 1 week with far less man-power than a behind the wheel test - and the data would very likely be more accurate. It would also be far easier to simulate different driving profiles. Given that the opposum's LEAF did see a decent number of miles, it's pretty clear that they did do some road testing to verify on-road behavior in the car. Perhaps other cars which showed more capacity loss got more road testing.

TurboFroggy said:

vrwl said:

Volusiano said:

There's an obvious contradiction here. According to the transcript above, Eric from Nissan said that the normal temperature range is within the blue and red ranges. But on the other hand, you're not supposed to keep the battery at the 120C level for more than 24 hrs. Well, 7 bars is between 98.2C to 122C, so if the temperature bar says 122C is normal, why can't the battery be under warranty at 120C for 24 hrs, if up to 135C (top range of 10 bars) is considered "normal" since it's not in the red?

Segments Degrees C (F)
12 60 (140)
11 57.5 (135.5)
10 55 (131)
9 52.5 (126.5)
8 50 (122)
7 36.8 (98.2)
6 23.5 (74.3)
5 10.3 (50.5)
4 -3 (26.6)
3 -6 (21.2
2 -9 (15.8)
1 -12 (10.4)
0 -15 (5)

Click to expand...

Yes, I had the same thoughts about that... "between the blue and red gauge squares" essentially means we could safely charge our batteries anywhere from 15.8 degrees F to 135.5 degrees F.

Click to expand...

The manual clear states ambient temperature, not battery temperature.

"Do not expose a vehicle to ambient
temperatures above 120F (49C) for
over 24 hours."

Page EV-2 : http://www.nissanusa.com/content/dam/nissan/pdf/techpubs/leaf/2012/2012-leaf-owner-manual.pdf" onclick="window.open(this.href);return false;

The reason for that is the diffrence in temps will cause the pack to cool down. Even at 120F ambient the pack can cool down to 120F which is 7-8 bars.

Click to expand...

At the end of the day, it's the battery temperature that matters, not the ambient temperature. When the manual says do not expose a vehicle to ambient temperature of above 120F for 24 hours, this implies that "do not let the ambient temperature at 120F transfer to the battery and cause the battery temperature to rise to 120F".

So the contradiction still exists, that you should not allow the ambient temperature, hence eventually the battery temperature, to rise to 120F. But on the other hand, the battery temperature at 120F (7 bars) is considered normal according to Eric of Nissan.

This is an excellent, clear, and thoughtful post.

Thank you.

drees said:

opossum said:

The only specific we were given was that our car tested out at 85% capacity remaining, which was 2nd best of the cars they had. The best was supposedly 86%. This makes no sense to us, as it does not agree with our real world range loss from a year ago under similar driving conditions.

Click to expand...

How much range do you suppose you've lost?

Assuming that 21 kWh usable is available when new (from 100% to turtle), 85% capacity remaining would indicate that you have 17.85 kWh usable now. At 4.0 mi/kWh that would represent a total range of 84 miles when new and now 71.4 miles.

But keep in mind that LBW appears to occur at the same point regardless of overall capacity loss - 49 GIDs or about 3.4 kWh before turtle.

Since one's "range anxiety" factor doesn't change - you still probably start looking for a charging station at LBW and avoid going below that if possible.

That means that your "safe" capacity has gone from 17.6 kWh to 14.45 kWh - a reduction in "safe" range closer to 18% than the indicated 15% - or 70 miles down to 58 miles at 4.0 mi/kWh.

This is worse if you normally charge to "80%" which is about 17.3 kWh usable before turtle when new and 14.7 kWh after 15% degradation.

Now your "safe" usable capacity has gone from 13.9 kWh to 11.3 kWh - at 4.0 mi/kWh that's 56 miles down to 45 miles.

That also means that drives that you used to make at 80% without issue - you now have no choice but to charge to 100%. When new your 80% "safe" range was 58 miles - after 1 year your 100% "safe" range is 56 miles.

Of course - in addition to this, the BMS could be doing something else weird which is giving the appearance of a more significant reduction in range. You wouldn't be the first to claim that.

Completely unacceptable after 1 year.

azdre said:

I'm shocked that they didn't do a driving range to LBW test with our car when they had it. I would think that would demonstrate the impact of this a lot more evident than some test that shows 85%.

Click to expand...

I'm not. A properly instrumented bench test could be set up and repeated multiple times in 1 week with far less man-power than a behind the wheel test - and the data would very likely be more accurate. It would also be far easier to simulate different driving profiles. Given that the opposum's LEAF did see a decent number of miles, it's pretty clear that they did do some road testing to verify on-road behavior in the car. Perhaps other cars which showed more capacity loss got more road testing.

Click to expand...

Volusiano said:

So the contradiction still exists, that you should not allow the ambient temperature, hence eventually the battery temperature, to rise to 120F. But on the other hand, the battery temperature at 120F (7 bars) is considered normal according to Eric of Nissan.

Click to expand...

1. Aren't you perhaps putting too much credence in the response of a NO-GAS-EV flunkee working under pressure a year ago?
2. Are you hypothesizing a 24-hour average ambient temperature of 120°F?
3. I suspect you got that table from the Wiki, but I think you may be misreading what it is trying to say. Couldn't it be saying that 98.2°F is the high end for 7 bars? If those are low end numbers, what does it mean that the low end of 0 bars is 5°F?
4. There seems to be something flaky about the numbers in the high end of that table.

My copy of the service manual contains a graph which suggests that a battery temperature of 120°F could display as 8, 9, or 10 bars depending on how much the battery has degraded.

Ray

planet4ever said:

Volusiano said:

So the contradiction still exists, that you should not allow the ambient temperature, hence eventually the battery temperature, to rise to 120F. But on the other hand, the battery temperature at 120F (7 bars) is considered normal according to Eric of Nissan.

Click to expand...

1. Aren't you perhaps putting too much credence in the response of a NO-GAS-EV flunkee working under pressure a year ago?

Click to expand...

I'm not putting credence on anybody. I'm just pointing out a contradiction. But on the other hand, that person Eric W. did put the caller on hold, supposedly to consult with somebody else (a manager/supervisor perhaps?) before giving the answer. Again, I'm not saying I believe one answer over the other. I'm just pointing out that there are contradictions given out by Nissan. Right now, I'm trusting my instinct that the 7th bar is in the bad range and not in the normal range like Nissan displays it.

planet4ever said:

2. Are you hypothesizing a 24-hour average ambient temperature of 120°F?

Click to expand...

I don't need to hypothesize anything. It's a straight quote from the owner's manual not to allow the car to be at ambient temperature for longer than 24 hrs. I'm just saying that on the one hand, the manual says that ambient temperature, which eventually will transfer to battery temperature, of 120F for 24 hours is bad. But on the other hand, the temperature bar read out, whether it be at 7 or 8 or 9 or even 10 temperature bars, is displayed in the normal range (white color and not red like the 11 or 12th bar). For sure the 10th bar at 131F (whether it be at the low end or high end of the 10th bar), not a red bar, is much higher than 120F. Hence a contradiction exists in what Nissan says and displays.

planet4ever said:

3. I suspect you got that table from the Wiki, but I think you may be misreading what it is trying to say. Couldn't it be saying that 98.2°F is the high end for 7 bars? If those are low end numbers, what does it mean that the low end of 0 bars is 5°F?

Click to expand...

Like I said above, it doesn't matter if the 7th bar has 98.2F as the high end or low end because the 10th bar at 131F, which is much greater than 120F, seems to be considered as normal by Nissan, hence displayed by Nissan as a white bar and not a red bar.

Hi all!

I'm not sure this was discussed in the forum, but there are now so many pages and I'm not sure.

My case is... don't you think it might be useful to document in the wiki the charger manufacturer/charging technology?

We already know that chargers can damage the electronics, but I think that there might some correlation with the charger manufacturer/charging technology and the battery capacity loss.

Looking at the WIKI and reading some posts, it has made be think that those who make L1 charging are in better shape than others, but maybe it's not the L1 mode that's beneficial, it's the charger manufacturer.

Maybe we find that some charger manufacturer + manufacturing date, or L1/L2/L3 charging modes are more damaging than others.

I have a strong feeling that there's not only one cause to the severe capacity loss, but a combination of factors, and one is the charger manufacturer/charging technology.