2016-2017 model year 30 kWh bar losers and capacity losses

[chirpyboy]

I got the BMS software update last week. Mine's a 2017 with 13k miles & 11/16 build.

Before:
11 bars
SOH=83.13%
AHr=66.07
Hx=77.59%

After:
12 bars
SOH=92.24%
Ahr=73.31
Hx=77.73%

[johnlocke]

Update on new battery after one month. 82.09 AH 363 GID's, SOH 103.20%, Hx 96.82%. 46966 mi. with just over 2000 mi on the new battery.
I had the software update done in late June but it appears that it was already done when the battery was changed. I haven't needed to to do a DCFC yet so I can't comment on charging rates with the new battery. Only real difference I see is that some regen is available at all times. I get one circle of regen available by the time I pull out of the driveway and LeafSpy says it's working. 3 circles by the time I'm down to 97% and all 4 by 94-95% down.

Battery health has actually improved slightly over the last month. I suspect that is due to the BMS learning the new battery. I expect it to take at least a year to see if the software patch actually does anything. I'll keep posting periodically for everyone's benefit.

I know range is a touchy subject, but are you getting a feel for range with the new battery?

Range appears to be about the same as it was when the car was new. Regen is better now so that might help mileage slightly.

[waikalua]

At 23,000 miles my 2016 Leaf SV lost it’s fourth capacity bar. I took it to the dealer for battery replacement and they said “there’s a recall on the lithium-ion battery controller (LBC) that we’ll do first, that may restore some of the bars.”

After an hour in the shop my Leaf miraculously has 11 bars again!

I’ve spent the last two years being frustrated that the extra money I spent for 30 kWh was a waste and somewhat bitterly having to adjust my lifestyle to compensate for the reduced range!

I’m beyond skeptical about this ‘software update.’ Six months ago Nissan was replacing batteries on cars with the same degradation pattern. Suddenly they eliminate a multi-million dollar physical liability with an easy software fix?

Since battery capacity is a MAJOR factor in the resale value of an EV, how is this different from odometer tampering?

There's a lot of experts on this forum, is this for real?

[dwl]

I’m beyond skeptical about this ‘software update.’ Six months ago Nissan was replacing batteries on cars with the same degradation pattern. Suddenly they eliminate a multi-million dollar physical liability with an easy software fix?

Since battery capacity is a MAJOR factor in the resale value of an EV, how is this different from odometer tampering?

There's a lot of experts on this forum, is this for real?

When we consider the warranty was 8 years and 4 bars were being lost at 2 years something was obviously wrong. It seems a fact that the BMS was incorrectly reporting capacity on a number of cars. Other capacity testing methods such as charging energy from flat and dynamometer run down confirmed some cars under reporting.

The firmware update seems a legitimate correction and better represents actual capacity but only time will show how accurate and what rate of degradation may now be seen.

[JPWhite]

Since battery capacity is a MAJOR factor in the resale value of an EV, how is this different from odometer tampering?

Re-programming the BMS has the unintended consequence of resetting capacity bars and other parameters. This will be temporary, probably settle down after a month. Expect to lose a bar or two again.

Odometer tampering is deceptive, intentional and permanent. This isn't permanent. Nissan's goal is not to disguise true battery degradation and it will settle down within a reasonably short period of time.

EV's (and modern cars in general) are like computers on wheels. When you call tech support one of the early troubleshooting steps will be to upgrade firmware to a current revision, it sets a baseline for troubleshooting. If that doesn't help then additional actions will be taken. This is no different, Nisan need to get your firmware to a current and known state and can act accordingly thereafter.

It can be frustrating to see what apears to be a valid warranty claim evaporate, but another month and you will know the true state of your battery and warranty eligibility.

[jbuntz]

Since battery capacity is a MAJOR factor in the resale value of an EV, how is this different from odometer tampering?

Re-programming the BMS has the unintended consequence of resetting capacity bars and other parameters. This will be temporary, probably settle down after a month. Expect to lose a bar or two again.

Odometer tampering is deceptive, intentional and permanent. This isn't permanent. Nissan's goal is not to disguise true battery degradation and it will settle down within a reasonably short period of time.

EV's (and modern cars in general) are like computers on wheels. When you call tech support one of the early troubleshooting steps will be to upgrade firmware to a current revision, it sets a baseline for troubleshooting. If that doesn't help then additional actions will be taken. This is no different, Nisan need to get your firmware to a current and known state and can act accordingly thereafter.

It can be frustrating to see what apears to be a valid warranty claim evaporate, but another month and you will know the true state of your battery and warranty eligibility.

I think the problem is Nissan did not disclose how the bars are calculated for warranty purposes. If they had then it would be easy to prove if the bms was reporting incorrectly.

Since they did not disclose then I think they should not change the formula mid stream. At least they should honor the warranty as written.

[JPWhite]

Since they did not disclose then I think they should not change the formula mid stream. At least they should honor the warranty as written.

Agree that Nissan have bungled the handling of this much the same as they bungled the 2011/12 battery issues.

However they can and should improve the BMS software when they can, would you prefer they leave it as is and have a bad BMS continually degrade packs due to mismanagement?

Let us remember Nissan is one of the few BEV manufacturers to have customer accessible battery capacity gauge.

The warranty as written does no reveal the algorithms, so they have done nothing to violate the warranty.

[goldbrick]

While I can believe that the BMS algorithm may be wrong and the firmware update makes it more accurate, a 2016 Leaf that loses its 4th bar within the warranty period qualifies for a new battery and you should be entitled to one. I think Nissan owes you a new battery or at least some amount of 'good will' if you are so inclined to grant them a waiver. I'm not a litigious person but if you come in 12 hours after the warranty period expires with a missing 4th bar you will be denied a new battery since it is out of the warranty period. It's all written down in black and white and what's good for the goose should be good for the gander.

[lorenfb]

I got the BMS software update last week. Mine's a 2017 with 13k miles & 11/16 build.

Before:
11 bars
SOH=83.13%
AHr=66.07
Hx=77.59%

After:
12 bars
SOH=92.24%
Ahr=73.31
Hx=77.73%

Again, isn't interesting that the Hx shows no improvement after the firmware "update"? Both Hx and Ahrs are highly correlated
as a battery degrades over time. This has been supported by posted time series data on both parameters here on MNL.

So we find that the two key battery parameters (Ahrs/relative battery conductance) have degraded more so on the 30kWh Leaf
than other Leafs. This has resulted in potentially higher warranty claims for Nissan, but only the parameter (Ahrs/bars) defined
in Nissan's warranty document is modified, thereby reducing its potential near term liabilities. We find, though, the these batteries
still exhibit a higher rate of degradation than other Leafs based on Hx.

[RegGuheert]

There's a lot of experts on this forum, is this for real?

I think the simple answer is, "We don't know, yet."

Thanks for providing the information you have posted. If you and others will please keep posting about your experiences with your 30-kWh LEAF's batteries we will eventually have a better picture of what Nissan is doing here.