Unusual Battery Degradation?

[apacheguy]

Note to media: The following words may not be quoted or otherwise referenced outside of the MyNissanLeaf forums.

My 2011 LEAF ended up on a flatbed last week for the first time due to a dead battery. I was 6 miles from my destination. I was driving a route I have driven in the car countless times and it had never failed until that day. Called Nissan roadside assitance and they were able to retrieve the car the following day.

I was scratching my head trying to figure out what went wrong. The Nissan tech called us back and said they discovered no problems with the car. When the car was returned to me I ran the "eco" information feed, as I am aware that it uploads usage data to CARWINGS. Sure enough, our data showed:

18.3 kW, 67.5 miles driven

I know for a fact that we started with 100% SOC, as the car had just been charged prior to departing. I also looked back at the historical data on CARWINGS and discovered several months ago I did the same trip and used 19.4 kW, 73.7 miles driven.

Again, I have done this trip several times and never had a problem making it to my destination. However, it seems that data is only uploaded to CARWINGS after I select the "eco" feed as noted earlier. Hence, the last available data point was from several months ago.

I have ~13,000 miles on the odometer. Can other users that have CARWINGS data report back some numbers? I'm trying to determine whether I should go in for a warranty claim on the battery.

 

[cwerdna]

Can you update your location info via User Control Panel (near top) > Profile (left side)? That way, we don't need to ask in future posts/threads or do sleuthing to deduce it.

Note to media: The following words may not be quoted or otherwise referenced outside of the MyNissanLeaf forums.
...
I'm trying to determine whether I should go in for a warranty claim on the battery.

How many capacity bars do you have left/how many have you lost? They're the thin bars on the very right pictured at http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss" onclick="window.open(this.href);return false;.

Why a warranty claim? Explain your reasoning.

We're going to need a lot more information, BTW. Perhaps you can be a guinea pig for the questions at http://www.mynissanleaf.com/viewtopic.php?p=275421#p275421" onclick="window.open(this.href);return false;. I realize that some of them don't really apply to your case.

 

[apacheguy]

Thanks for your reply, cwerdna.

Can you update your location info via User Control Panel (near top) > Profile (left side)? That way, we don't need to ask in future posts/threads or do sleuthing to deduce it.

Done. I live in So Cal.

How many capacity bars do you have left/how many have you lost? They're the thin bars on the very right pictured at http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss" onclick="window.open(this.href);return false;.

Yes, I have full bars. However, the first bar represents 15% loss according to the wiki you referenced. Hence, the fact that I have all bars does not mean there aren't problems with the battery.

Why a warranty claim? Explain your reasoning.

If I'm only seeing 18.3 kw, out of a usable 21 kw (when new), that would represent 13% degradation. This is simply unacceptable with a car less than 2 years in and just 13,000 miles. That would also explain why the first bar still hasn't gone away for me (15% degradation necessary).

 

[cwerdna]

Thanks for answering and updating your location.

Why a warranty claim? Explain your reasoning.

If I'm only seeing 18.3 kw, out of a usable 21 kw (when new), that would represent 13% degradation. This is simply unacceptable with a car less than 2 years in and just 13,000 miles. That would also explain why the first bar still hasn't gone away for me (15% degradation necessary).

If those numbers are accurate, 13% degradation (and no capacity bar loss) isn't going to get you anywhere in terms of warranty. Prior to http://www.mynissanleaf.com/viewtopic.php?f=4&t=11043" onclick="window.open(this.href);return false;, there was NO battery capacity warranty.

Even though one has been announced, it doesn't seem like it's been rolled out and won't take effect until you've lost 4 capacity bars or are below 70% capacity, assuming that happens prior to 5 years/60K miles.

If you have one or more bad module, they would probably swap them out. It has happened before.

 

[scottf200]

<snip>I was 6 miles from my destination. I was driving a route I have driven in the car countless times and it had never failed until that day.<snip>
18.3 kW, 67.5 miles driven
<snip>
I did the same trip and used 19.4 kW, 73.7 miles driven.
<snip>
I have ~13,000 miles on the odometer.
<snip>

So you take this 73.7 mile trip a lot but how may years did you think you were going to be able to take this trip? All batteries degrade.
Perhaps you leased it so you'll be OK but if you bought it then you may not have taken into consideration expected loss of miles/capacity.
Hopefully there is a convenient charger long this route where you can stop for a 1/2 hour break then you'd be OK.

 

[apacheguy]

Hmm, that is very unfortunate that they do not offer a more reasonable warranty on capacity loss. I feel that 13% loss is definitely abnormal for a battery after less than 2 years. If I can't drive that route in my LEAF that would be a deal breaker for me and I would be forced to sell it.

If you have one or more bad module, they would probably swap them out. It has happened before.

How would I go about getting them to check for this? The tech I spoke to said no problems were detected, but I'm not convinced they did a thorough check.

 

[cwerdna]

Hmm, that is very unfortunate that they do not offer a more reasonable warranty on capacity loss. I feel that 13% loss is definitely abnormal for a battery after less than 2 years. If I can't drive that route in my LEAF that would be a deal breaker for me and I would be forced to sell it.

This exactly why some people lease. This is part of why I will likely lease and not buy. Since you live in CA, you have numerous EV and PHEV choices. The Rav4 EV will more than likely meet your range needs. The $10K Toyota So Cal discount and dealers discounting will likely make it more appealing.

Some folks in Phoenix and other hot climates lost a capacity bar or more in the middle of their 2nd summer. One poor sap lost 4 capacity bars. A bunch of Phoenicians were able to get Nissan to buy back their car or terminate their lease early due to rapid capacity loss. This wasn't without a LOT of effort though.

Sort of a summary at http://www.mynissanleaf.com/viewtopic.php?f=30&t=9694" onclick="window.open(this.href);return false;, instead of reading the over 500 page thread.

Tony Williams ran a range test that included some of the capacity bar losers at http://www.mynissanleaf.com/viewtopic.php?p=225481" onclick="window.open(this.href);return false; and http://www.mynissanleaf.com/viewtopic.php?f=31&t=10040" onclick="window.open(this.href);return false;.

If you have one or more bad module, they would probably swap them out. It has happened before.

How would I go about getting them to check for this? The tech I spoke to said no problems were detected, but I'm not convinced they did a thorough check.

I don't know. http://daveinolywa.blogspot.com/2013/03/the-week-in-evton-carwings-is-your.html" onclick="window.open(this.href);return false; is a recent story. I actually happen to know DaveinOlyWA (we've met before) and I actually have met the person he references (Rob Greenlee). I don't know if Rob's active here on MNL.

I think there have been a few other instances of replaced modules. I don't have links OTOH.

Since you're in So Cal, it would be interesting if you borrowed a gid-meter (I'm assuming you don't have one) and indicated how many gids show after the car's fully charged and the batteries have balanced.

 

[Stoaty]

Southern California is a big area. We need to know a bit more to say if this is out of the norm. What city do you live in? How often do you charge to 100%, and how long do you leave the Leaf at full charge before driving? How many hours a day (average) do you park in the sun?

 

[surfingslovak]

How would I go about getting them to check for this? The tech I spoke to said no problems were detected, but I'm not convinced they did a thorough check.

I would file a claim with the EV-NOGAS hotline, and complain to the dealer. While the likelihood that there is anything besides "normal" capacity loss is low, at least your voice will be heard. Nissan is supposed to announce battery pack replacement prices this spring. There is a chance that they will be attractive enough to allow customers with "moderate" loss, which is not covered by the new capacity warranty, to refresh their battery pack.

 

[camasleaf]

Were the driving conditions the same?
I have a 40 miles one way trip that I do often. I used to get 4.8 mile/kWh at 55mph on low 60s no rain and no wind. That would take me round trip. Since there is now a QC at the destination, I drove 65-75 and use defog more than before on 40 degrees weather with rain and wind. My average was 3.2miles/kWh.

 

[cwerdna]

BTW, I thought about this more. If you bought the Leaf to do a 73.7 mile trip w/o charging somewhere in the middle or at one of the stops, and quite of bit of it is at freeway speeds, you made a mistake.

As others have pointed out, the battery will degrade and the '11-'12 Leaf was only rated at 73-miles of range on the EPA test, which was run on a new battery. You're only going to have more trouble making the trip as the battery degrades further and if you need to use the heat or AC more.

 

[apacheguy]

Thanks folks for all the replies. Actually, the LEAF is leased partly for this reason. I knew that the batteries would suffer degradation, but it never occurred to me that it would be this severe after less than 2 years of ownership. I thought I could easily make it 36 months, when the lease is up.

 

[cwerdna]

^^^
Cool!

Well, there are likely many things you can do to eek out a bit more range (e.g. driving slower, taking slower routes, increasing your tire pressure, turning OFF your HVAC (see http://www.mynissanleaf.com/viewtopic.php?p=148844" onclick="window.open(this.href);return false, etc.)).

However, if you want help, I think folks here need to know some basic info from you first, such as by answering the questionnaire. As I said, a gid-meter on your car at 100% charge after batteries have balanced would be interesting, as would m/kwh readings for your driving, esp. that trip (from the dash display. I don't know about Carwings.)

 

[Reddy]

So. Cal is a big area so I can only make a guess here. However, LA reported temps near 50 F on Sunday, so I will surmise that the car was pretty cold soaked (at least for you guys down there). Is this your first long drive with a battery below 70 F? According to Tony's range chart you will lose ~5%. I've also seen reduction for wind, rain, snow, and even fog. As others have said, 70+ miles will be a challenge at times, easy other times. Remember, the world isn't a 75 F bubble, even though many people live in one.

Reddy

 

[TonyWilliams]

As you have probably learned, you have no claim against Nissan because there was no warranty for capacity. You're in great shape compared to a few folks with up to 30% capacity loss.

 

[cwerdna]

Sounds like the OP is a candidate for a gid-meter, esp. a fancier one like http://www.mynissanleaf.com/viewtopic.php?p=269771#p269771" onclick="window.open(this.href);return false;. Using it, he could better gauge how close he is to running out and whether or not he needs to alter his driving and by how much, in order to successfully reach his destination.

For instance (from an example there), if he's got 45 miles left in the trip and he wants to arrive at LBW, then he'll need to have somewhere between 3.5 and 4 m/kwh efficiency for the remainder of the trip.

 

[apacheguy]

Well, currently my "GID" meter is the time to full charge according to dash display. When the car shutoff, the display read 6:30 hrs to full charge on 240. I will be looking for a charger as soon as I see 6 hrs from now on.

Edit: in the not too distant past, I took my LEAF past 7 hrs to full charge with no problems. Granted, it gave me a low battery charge, but it did not enter turtle mode. I know something is definitely wrong here.

No, the battery was definitely not cold soaked. I plugged it in and charged just hours before I departed. Hence, the battery was warm. Additionally, at the time I departed temps were 60+.

 

[edatoakrun]

...data showed:

18.3 kW, 67.5 miles driven

I know for a fact that we started with 100% SOC, as the car had just been charged prior to departing. I also looked back at the historical data on CARWINGS and discovered several months ago I did the same trip and used 19.4 kW, 73.7 miles driven.

Again, I have done this trip several times and never had a problem making it to my destination. However, it seems that data is only uploaded to CARWINGS after I select the "eco" feed as noted earlier. Hence, the last available data point was from several months ago.

I have ~13,000 miles on the odometer. Can other users that have CARWINGS data report back some numbers? I'm trying to determine whether I should go in for a warranty claim on the battery.

="apacheguy"]...No, the battery was definitely not cold soaked. I plugged it in and charged just hours before I departed. Hence, the battery was warm. Additionally, at the time I departed temps were 60+.

Remember that a LEAF battery pack has significant thermal mass, so battery temp, and the amount of kWh your battery will accept at "100%", is determined by not only the ambient temperature, but also your LEAFs driving and charging history during the previous few days.

And even if your dash temp bars were identical and constant for the two trips you mentioned, you could have ~3% variation in capacity due to the ~25 f variation in battery temperature, within one dash temp bar, in the 4 to 6 range.

Do you remember if and when you got the LBW and VLBW on your earlier 19.4 kWh, 73.7 miles drive?

What was the date of that trip?

Below is my own record of available kWh as reported by CarWings, along with the dash temp bar status during the range tests.

Note that on my first test, only few months from new, I only had 18.7 kWh available. Also note that although my own LEAF has reported capacity loss, it has not lost a significant amount of range on tests controlled for temperature, speed, and driving efficiency.

This doesn't mean your LEAF has not lost capacity, but IMO, you may not be able rely on CarWings kWh use for actual capacity reports, even though they are clearly superior to using either the dash or nav screen m/kWh reports to try to calculate the same capacity data.

So IMO, the only way to accurately determine capacity loss from the time of the first to the second drives you mention, would be to have recorded all the variables, charging and driving temperature, driving efficiency (avoiding both regen, which is reported by CW and also your use of the disk brakes, which is not) and most importantly, the speed or travel time of both tests. Just a few mph variation, could give the variable range results you mention, from identical initial charges. What do you recall about these factors?

BTW, your regen use on both trips should still be available from the CarWings "rate simulation" page.

If you wait more than a few months to look it up, it may not be available at the CW site, but can be downloaded, using the option at the bottom of the page, for the month you need.

Below is how Carwings has reported the total energy use from "100%" to ~VLBW on my warm climate LEAF two years from the factory and with ~16,000 miles on the odometer.

While the reported kWh use has dropped quite a bit, My LEAF has displayed no significant loss of range from my first test, to most recent, on range tests of 95-113 miles, when corrected for all test variables, including speed, temperature both when charging and when driving, and my own driving efficiency (as reflected in the regen kWh reported by CarWings).

Of course my battery has lost capacity in the last 18 months, it just not yet a large enough loss to show up clearly in a range test, and is, IMO, nearly certainly far less than the kWh use results below, showing capacity loss approaching 15% just over the last 18 months (when adjusted for battery temperature) would indicate:

All charges prior to testing were to “80%", battery allowed to return to ambient temperature, and then charged @ 16 A 240 V to “100%”, two to three hours before range/capacity test begins, and then left plugged into the EVSE until departure.

IMO The distance driven at the point where the battery temp bars increased, when that has occurred, is useful data as to the relative battery temp and temperature the (temperature variable) battery capacity when the "100%" charge was completed.

9/7/11 18.7 kWh from "100%" to VLBW, 6 dash battery temp bars constant (as recalled later)

5/10 12 17.2 kWh, 5 to 6 temp bars ~mile 73

5/31/12 17.5 kWh, 5 to 6 temp bars ~mile 5

6/17/12 17.5 kWh, 6 temp bars constant

8/18/12 17.0 kWh, 6 temp bars constant

8/30/12 16.8 kWh, 6 temp bars constant

9/08/12 16.7 kWh, 5 to 6 temp bars ~ 4.6 miles

10/1/12 16.6 kWh, 6 temp bars constant

11/3/12 16.2 kwh, 4 to 5 temp bars ~mile 14

1/31 15.7 kWh, 4 to 5 temp bars ~mile 24

2/16/13 15.8 kWh, 4 to 5 temp bars ~mile 18

3/1/13 15.6 kWh, 4 to 5 temp bars ~mile 18

3/13/13 16.0 kWh, 5 bars temp constant


I think it is nearly certain, that the LEAF "gauge error" that has shown up in premature battery capacity bar loss and Wh/gid error in other LEAFs is also displaying itself in the dash and nav screen m/kWh, and also in the (more accurate) CarWings kWh use reports, from my LEAF, as I have posted above.

IMO, any LEAFer who can learn to use CarWings, may see the same sort of results I have, and also be able to largely differentiate any range loss due to real battery capacity loss, from their LEAF's questionable kWh use reports, as I believe I have been able to do.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=11591&start=20" onclick="window.open(this.href);return false;

 

[apacheguy]

Thank you, edatoakrun, for a very thoughtful, in depth response. I will look more closely at your data when I have time later today.

Off hand, I can tell you a few things. First, the 19.4 kW trip was back in July 2012. I made the same trip several times in the span between Aug-Dec, however, there is no data on CARWINGS for those months even when I download it as a spreadsheet. The spreadsheet is completey blank. Also, I do not recall when the warnings appeared during that trip.