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

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Reading those scans from Nissan, it seems clear this won't affect range, just the display on the dash and SOH readings in LeafSpy. If you have reduced range this won't help :(
 
^^^
Would be very interesting to compare a 3 bar loser (before fix) with this fix applied vs. a 30 kWh car with the fix applied that was 12 bars before and after fix.

From https://www.facebook.com/groups/NissanLeafOwners/permalink/1899697456794901/, where I first learned of the bulletin FAQ eventually (you may need to log into FB to see the same FAQ pages posted (days after the work was completed) in the comments), that guy's car as a side effect got his capacity bars reset. That might be required (car/BMS has to relearn the pack?) or his 12 bars might be actually be the "accurate" amount.

I'm thinking of a tests like: steady speed range test w/identical tires and tire pressure until turtle or well below VLBW w/no HVAC usage in dry weather and kWh count of car being charged from turtle to full for the above two cases. Would need to have near identical supply voltages though: no comparing to 208 vs 240 volts charging. Both need to be ~208 or both need to be 240.

And, of course, if we have a 30 kWh car that's down 3 bars after the fix has been applied, the above data would be interesting.
 
cwerdna said:
I'm thinking of a tests like: steady speed range test w/identical tires and tire pressure until turtle or well below VLBW w/no HVAC usage in dry weather and kWh count of car being charged from turtle to full for the above two cases. Would need to have near identical supply voltages though: no comparing to 208 vs 240 volts charging. Both need to be ~208 or both need to be 240.
One of the issues with the BMS reporting is the point at which LBW and VLBW are turned on relative to the acutal capacity remaining in the pack. We are relying on a calculation that is estimating 4kWh and 2kWh respectively and this may be wrong on some cars.

A range test that notes when these warnings light up adds the dimension of perceived range (which may change with the update) while running well below VLBW perhaps until flat is more related to the battery capacity (which probably won't change with the update).
 
dwl said:
cwerdna said:
I'm thinking of a tests like: steady speed range test w/identical tires and tire pressure until turtle or well below VLBW w/no HVAC usage in dry weather and kWh count of car being charged from turtle to full for the above two cases. Would need to have near identical supply voltages though: no comparing to 208 vs 240 volts charging. Both need to be ~208 or both need to be 240.
One of the issues with the BMS reporting is the point at which LBW and VLBW are turned on relative to the acutal capacity remaining in the pack. We are relying on a calculation that is estimating 4kWh and 2kWh respectively and this may be wrong on some cars.

A range test that notes when these warnings light up adds the dimension of perceived range (which may change with the update) while running well below VLBW perhaps until flat is more related to the battery capacity (which probably won't change with the update).

And how about a simple LeafSpy test before & after, measuring all the key battery parameters, e.g. SOH, Hx, and most importantly Ahrs?
Those three parameters should not change if the "fix" is to just change the thresholds for the bar drop points, right? Hopefully, this "fix"
doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".
 
lorenfb said:
And how about a simple LeafSpy test before & after, measuring all the key battery parameters, e.g. SOH, Hx, and most importantly Ahrs?

LeafSpy just reads out the BMS estimates of battery pack condition. The BMS estimates are a potential issue, as these (in a 2014) can vary at least +12% -3% from my best battery capacity estimate from a charging energy test. LeafSpy can't be more accurate than the BMS.


lorenfb said:
Those three parameters should not change if the "fix" is to just change the thresholds for the bar drop points, right? Hopefully, this "fix" doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".

If the issue is that the BMS estimates are too low, then the SOH and Ahr numbers should increase after the firmware update and enough time to recover from the BMS reset. The key question is: "Does the recharge energy and/or distance actually driven to empty more closely match the BMS estimates before the firmware upgrade? Or after the firmware upgrade?"
 
WetEV said:
lorenfb said:
Those three parameters should not change if the "fix" is to just change the thresholds for the bar drop points, right? Hopefully, this "fix" doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".

If the issue is that the BMS estimates are too low, then the SOH and Ahr numbers should increase after the firmware update and enough time to recover from the BMS reset. The key question is: "Does the recharge energy and/or distance actually driven to empty more closely match the BMS estimates before the firmware upgrade? Or after the firmware upgrade?"

Right, then do the Leaf Spy tests before and after! It's another reference point about the "reset". How difficult is that?
And who really cares about the range estimates of the GOM anyway? Nissan is really just concerned about the bars
dropping and its liability.
 
lorenfb said:
Hopefully, this "fix"
doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".

I suppose we'll find out. As a historical data point, the BMS firmware update for he 2011/12 packs *did* reset battery parameters.

On 8/2/2013 my Ahr was 55.5763 first thing in the morning prior to the update
After the update was applied the Ahr increased to 59.7812

by 8/23/2013 the Ahr reading was back to 55.6944

I believe the update process will reset parameters and require the BMS to relearn the battery from scratch.

Back then LEAFspy didn't record SOH so not sure how it changed.
 
JPWhite said:
lorenfb said:
Hopefully, this "fix"
doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".

I suppose we'll find out. As a historical data point, the BMS firmware update for he 2011/12 packs *did* reset battery parameters.

On 8/2/2013 my Ahr was 55.5763 first thing in the morning prior to the update
After the update was applied the Ahr increased to 59.7812

by 8/23/2013 the Ahr reading was back to 55.6944

I believe the update process will reset parameters and require the BMS to relearn the battery from scratch.

Back then LEAFspy didn't record SOH so not sure how it changed.

Hopefully the same occurs with this "minor" firmware update.
 
happyfunball said:
Reading those scans from Nissan, it seems clear this won't affect range, just the display on the dash and SOH readings in LeafSpy. If you have reduced range this won't help :(

A better way of looking at this is that no, the fix does not give you more range, i.e. the 30 kWh battery will still be rated at 103 miles, not suddenly 151 miles. And if your 16-17 LEAF was a low mileage car, but had lost 3-4 bars, and the range had gone down, it's not that the battery had degraded, it is still fine, it's the monitoring calculations were bad. This fix, restores the ability of the car to use its full capacity that is still there.

Now of course the old saying: "Your mileage may vary" is applicable here. The fix won't restore battery capacity that has been lost through normal usage, but what it will do is provide more accurate information on the health of the battery.
 
LTLFTcomposite said:
Sounds like they are reprogramming it so the bars don't drop so fast. Big money savings for Nissan, owners lose out.

If you take the POV of a freeloader trying to game Nissan out of a free battery yes. But in reality, owners are the big winners here, because this fixes a flaw that indicated that their battery was going bad when it really wasn't.

It also saves Nissan a big warranty expense of replacing batteries that did not need to be replaced.
 
On an unrelated thing I am taking my '16 Leaf in for warranty service next week and will ask that they perform the update at the same time. I will be sure to capture before/after LeafSpy stats.

@rcm4453 given you are in MN, like me, and have lost bars already on your '16 Leaf I will be super interested in your analysis as well.
 
mn4az said:
On an unrelated thing I am taking my '16 Leaf in for warranty service next week and will ask that they perform the update at the same time. I will be sure to capture before/after LeafSpy stats.


Great!
 
rcm4453 said:
OrientExpress said:
It's great news that the BMS reprogramming fix has finally hit the streets. Nissan has been testing this fix since last year when it was first observed. In some cases they are still replacing the entire pack, but now most cars presenting with the phantom accelerated capacity loss can be fixed.


That's not a good thing will mean many won't be getting a new battery. If you're down 2 bars like the guy on FB was, they reprogram the BMS now it shows 12 bars isn't Nissan just hiding the capacity loss to avoid so many battery replacements? Sure sounds like it to me! After all when has Nissan ever had the consumer's best interest in mind?

Yeah...NO.
 
johnlocke said:
I can assure you that my battery loss was not a "Phantom Loss". My range decreased from 90 miles at VLBW to 65 miles at VLBW and 53 miles at LBW. LBW went from 13% to 21% over the course of 30 months. This was a real loss of range. Nissan has monkeyed around with the values of the capacity bars to confuse and disarm consumers. The first bar doesn't disappear until the battery is down by 20%. With 12 bars available the first bar ought to vanish at 92% of original capacity. Four bars down is actually 62% of original capacity. Nissan won't even define what a four bar loss actually is and uses confusing language ("more than a three bar loss") in the owners manual. Nissan might as well have put a simple warning light "Change the Battery" instead of a misleading gauge and just been upfront about it.


The BMS controls what the car can use or see. The issue here is its possible that the BMS prevented the car from using pack that was ok.
 
jbuntz said:
And why is it that it is only cars in TX Fl AZ So Cal are the ones that have the BMS problems ??

COMPLETELY UNTRUE!!

There are people in my region who have lost 2 bars in less than 20,000 miles. Now that might seem "better" than what you are seeing but remember, I went nearly 30,000 miles with a 1-3% loss. I was projected to have 12 bars at 100,000 miles EASILY
 
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