New Leaf 2016 SL, Bad Battery?

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Cryptizard

Well-known member
Joined
Oct 3, 2016
Messages
46
Location
Baltimore, MD
Hi everyone, I am new here but I am having an issue I was hoping to get some insight on. I have a new 2016 Leaf SL that I got last month and the battery has been acting very strange. Every morning when I get in it is fully charged and displays an expected range of close to 120 miles. My commute is 30 miles one way, relatively flat and I never go faster than 65 MPH. I also don't use climate control because the weather has been nice so far. By the time I get home, it usually displays 25-30 miles left, with about 25% battery charge. I should also say that my average miles/kWh on the dash is always above 4. I thought this was weird, but chalked it up to the milage estimate being overly optimistic.

However, recently looking at it more closely, I consistently only use 25% of the battery and about 30 miles of the range on my way to work. On the way back, it drops from around 65% charge to about 30% charge in only a few miles. There are points where I would glance down at the mileage and watch it drop by 5-10 miles at a time. I also noticed today when I went to a fast charging station that it charged from 20% to 75% of the battery using only 10 kWh on the meter, which shouldn't be possible if the battery holds 30 kWh. In fact, it is behaving in all manners as if it actually only has about 20 kWh of capacity, but the mileage estimate doesn't realize that and has to "catch up" somewhere in the middle of the discharge cycle.

Has anyone had anything like this happen? Any idea on what could be causing it? Should I go back to the dealership? I don't think they know a lot about Leafs because I already had an issue with the cellular connection in the car not working and they had no idea how to fix it, until I showed them a post on this forum indicating what the problem likely was.
 
Just to be clear: you are looking at the State of Charge display, which shows an actual percentage, as well as the (worthless) estimated range display? The latter can drop very quickly, while the former should not.
 
Cryptizard said:
Yes, I have seen the battery percentage indicator drop 5% or more in under a minute.

Unless the accelerator is floored and you are climbing a hill at the same time, this is not normal. The first 2% of a 100% charge often drops rapidly, but not 5%.
 
Doesn't sound like anything I've experienced in my 2016 SVs. We pretty much get 1 mile per % on the SOC display in the dash. The GOM is also surprisingly accurate for daily driving.

I would be taking that car in to the dealer. If they don't seem interested in troubleshooting, find a dealer who is, or even call Nissan EV support #. You shouldn't have to put up with that.
 
Cryptizard said:
... it drops from around 65% charge to about 30% charge in only a few miles... ...when I went to a fast charging station that it charged from 20% to 75% of the battery using only 10 kWh on the meter...
These 2 things lead me to think something is wrong.

You should have at least 27 kWh usable.
 
I took it to the dealership and they said all the tests came back okay and that the behavior is normal. This is somewhat frustrating to me, how could this be normal? I drive as conservatively as possible, always getting 4.0+ average miles/kWh on the dash, not using climate control, and I only get 80 miles on a charge.

Putting aside that the math just doesn't work there (4 miles/kWh * 30 kWh = 120 miles), I can't imagine anyone being able to get the advertised 107 mile range if I am only getting 80 driving conscientiously and not using any of the features of the car. What ranges are other people experiencing with their 30 kWh Leafs?
 
Your description of miles driven and remaining charge sound about right for a well-balanced nearly new 24 kWh battery. You should not have to deal with this on a new car, but maybe it would be worthwhile to get Leaf Spy to look at the car's battery data independent from the dealer.

Gerry
 
GerryAZ said:
Your description of miles driven and remaining charge sound about right for a well-balanced nearly new 24 kWh battery. You should not have to deal with this on a new car, but maybe it would be worthwhile to get Leaf Spy to look at the car's battery data independent from the dealer.

Gerry
So you're suggesting that Nissan installed the wrong battery type (a 24kWh one, rather than the 30kWh) in the OP's 2016 SL?
 
Have you done a full discharge range test, where you fully discharge the battery until turtle mode?

What you describe does sound like some kind of manufacturing defect to me, although I have my doubts that the battery itself is the culprit.

My hypothesis, is that if you do a full discharge range test, your car will still go the normal value for your model (ex: around 107 mi), but that there may be a problem with the instrumentation on your car.

On my 2015 S, the LEAF dash SOC meter and the GOM always decrement smoothly in single digit value increments (Ex: 54% --> 53%, no jumping from say 54% --> 48%, no matter how aggressively you try to drive it). The scales aren't fully linear (especially the top 2% reported SOC as others have noted), but they are a reasonable approximation.

If your dash SOC meter or GOM are jumping multiple digits at a time, this may suggest an electronic instrumentation issue.

One theory, would be that the microcontroller ADC (analog to digital converter) could have some manufacturing defect, causing it to have large INL/DNL discontinuity errors, but is otherwise working normally. This could have the effect of making certain ADC codes much bigger/"stickier" than others, while leaving voids/gaps in the normal ADC code range. This would explain the odd jumping behavior in the SOC/GOM, without requiring the battery itself to be defective.

I can't imagine a "normal" battery failure mode that would result in a sharp drop in battery voltage when it is only 50% discharged (yet still go for 20+ miles after the drop). If there was one weak cell in the series stack, I would expect that the car to work normally from SOC 100% down until the weak cell is fully depleted (say at 50% total pack SOC level), at which point the problem cell voltage would collapse. In this case, I suspect the car would enter a power limited mode, or hard shutoff, in order to avoid reverse charging the weak cell. Allowing the rest of the pack to continue discharging would reverse charge the weak cell, which is dangerous and could cause the weak cell to catch on fire. Therefore, I would assume that there must be protection against this scenario built into the LEAF control system.

I would second the suggestion to get LEAF Spy with an appropriate OBD II reader. I would also suggest reading up on your state's lemon laws. I think in my state the dealer gets 3 good faith attempts to repair a defective car, and if they are too incompetent to fix the car, they become obligated to buy the car back from you.

It is no surprise to me that the stealership claims the observed behavior is "normal". All this really means is that the dealer hooked up a scan tool to the car, didn't see any trouble codes of relevance, didn't really know how to proceed, so they just gave the car back to you and said everything is working great.

Before taking the car back to the stealership a second time, I would set up a video camera and capture the LEAF dash SOC/GOM jumps (assuming that they do in fact move in >1 unit decrements). I would also do the full discharge range test and fully document the results and the associated driving conditions (especially average speed and elevation).

If your car really does turtle after 80 miles at <= 65MPH when brand new on level terrain with no wind and minimal or no HVAC usage, there is definitely something wrong, since the 24kWh models readily achieve this when new.
 
Levenkay said:
GerryAZ said:
Your description of miles driven and remaining charge sound about right for a well-balanced nearly new 24 kWh battery. You should not have to deal with this on a new car, but maybe it would be worthwhile to get Leaf Spy to look at the car's battery data independent from the dealer.

Gerry
So you're suggesting that Nissan installed the wrong battery type (a 24kWh one, rather than the 30kWh) in the OP's 2016 SL?
I don't know that he's doing that... before I even saw the above quote, I was thinking I would ask the OP, "not to be rude, but are you absolutely sure you received an SL model?"
I would estimate the chances of Nissan putting the wrong battery in an SL at way less than 1% of 1%... I would put the chances of a Dealer trying to "put one over" on a customer at greater than 50%. :shock:
 
Is the trip more or less completely flat, or is there a small elevation change, downhill on the drive in, and uphill on the drive home? You might want to check this with...Google Maps, maybe? At 65MPH, a long but slight grade might drain the pack that much...
 
I am in a similar boat as the OP. I recently purchased a new 2016 SL, verified as SL as I have the solar panel, and when I checked the vehicle with LeafSpy while on the lot at only 135 miles I found the SOH% at 97.

Shortly after taking ownership, and doing a full charge to 100%, the SOH% plummeted to 88%. There are screenshots of my LeafSpy along with lots of good info on the 30kwh battery here: http://www.mynissanleaf.com/viewtopic.php?f=44&t=20924
 
Cryptizard said:
My commute is 30 miles one way, relatively flat and I never go faster than 65 MPH. I also don't use climate control because the weather has been nice so far. By the time I get home, it usually displays 25-30 miles left, with about 25% battery charge. I should also say that my average miles/kWh on the dash is always above 4. I thought this was weird, but chalked it up to the milage estimate being overly optimistic.

However, recently looking at it more closely, I consistently only use 25% of the battery and about 30 miles of the range on my way to work. On the way back, it drops from around 65% charge to about 30% charge in only a few miles. There are points where I would glance down at the mileage and watch it drop by 5-10 miles at a time. I also noticed today when I went to a fast charging station that it charged from 20% to 75% of the battery using only 10 kWh on the meter, which shouldn't be possible if the battery holds 30 kWh. In fact, it is behaving in all manners as if it actually only has about 20 kWh of capacity, but the mileage estimate doesn't realize that and has to "catch up" somewhere in the middle of the discharge cycle. .

The following are averages, I'll be at one-year mark on Dec. 15, 2016. I've never seen the percentage (NOT the GOM) drop as rapidly as yours did (65% to 30%) unless it was on a hill or at high speed, or both.

Average charge: 21% to 80%
Average milage per charge: 91.2 [longest was 116.7 miles with 12% left on GOM]
Average m/kWh: 3.8 to 4.5 [lowest average was during Texas summer with AC]
 
Thanks for all the info guys. I got an ODBII adapter and tried LeafSpy just now and it shows 27 kWh at full charge. That seems a little low, but not low enough to be causing the drastic drop in mileage that I am seeing. I have not tried a turtle test, the lowest I have gotten the batter was about 18% I think. The whole thing could be an instrumentation error because it does seem to start discharging more slowly at around 25%. I will try to do a full to turtle test and see what what I get.

I am also having some trouble figuring out all the information that I get from LeafSpy and the documentation doesn't really help. What are the "normal" values for some of these supposed to be? For instance, this is the graph of my battery cells:

IMG_0074.PNG


According to the documentation, red means that the cell is being bled to increase balance, but all of them are red except for one blue one. I have seen other screenshots from LeafSpy where they are all blue. And one of the bars is dramatically lower than the others, does that mean something?

Also, this is the graph of voltage differences, which are higher than I have seen in other examples that people have posted but is it high enough to be worrisome?

IMG_0075.PNG


Thanks for all the help everyone, I appreciate it. If there is some guide that I can read to answer these questions myself please point me toward so I don't have to keep bothering you nice people :-D
 
Assuming you're doing a normal daily commute changes in elevation shouldn't make much of a difference at all. After all, if it's downhill one way, it's uphill the other way. I've got a 2000 ft. elevation change each way on my 55 mile round trip daily commute. Downhill is a breeze and only uses 20% of my charge. Going home is another matter and I use 40% of the battery on the way back going uphill. That said I still average 3.8mi/KWH pretty consistently. Overall, I get 90-95 mi range on a charge and I drive mostly on freeways and main roads at or above the speed limits with the A/C blasting. A/C or Heating seems to cost only a couple of miles in range most of the time.

What I have noticed is that regen isn't effective until the battery drops to below 95%. I can pick up a 2-3 % going downhill if the battery is below 95% but 1% or less if the battery is above 95%. The guess-o-meter is based on how you are currently driving so it varies considerably depending on whether you're on the freeway or surface streets. The % meter is much more consistent and I normally figure 1 mile per %.

The most important number to look at in Leafspy is the AH number. That tells you the condition of the battery. A new battery should read around 79AH (i've seen a range of 73 AH to 81 AH reported on new vehicles with a 30 KWH battery). That number drops with use. The loss depends more on average temps than anything else. Heat is bad for the battery. With almost 16,000 mi on my Leaf and a hot summer my battery is down to 328 GIDs and about 71.5AH from 363 GIDs and 79.3AH when new.
 
I start and end at sea level. There are a few hills on the way but the total elevation is unchanged so I have to go up and down them both ways.
 
Is it just me, or does cell 51 look like it may be marginal? Would be interesting to see if that cell is limiting the whole pack. What happens to it on a longer drive?
 
gshepherd said:
Is it just me, or does cell 51 look like it may be marginal? Would be interesting to see if that cell is limiting the whole pack. What happens to it on a longer drive?

I just got the ODBII connector this morning and I haven't driven it anywhere yet. I probably won't go on a longer drive until work on Monday so I will have to wait until then to find out for sure.
 
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