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

Posted: Wed Jun 13, 2018 6:57 pm
by webeleafowners
Thank you to Orient Express for the above post. It is very clear. I'll wait for the message.

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

Posted: Thu Jun 14, 2018 2:38 am
by happyfunball
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 :(

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

Posted: Thu Jun 14, 2018 2:45 am
by cwerdna
^^^
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/NissanL ... 456794901/, 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.

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

Posted: Thu Jun 14, 2018 5:38 am
by dwl
cwerdna wrote: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).

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

Posted: Thu Jun 14, 2018 5:53 am
by lorenfb
dwl wrote:
cwerdna wrote: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".

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

Posted: Thu Jun 14, 2018 6:33 am
by WetEV
lorenfb wrote: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 wrote: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?"

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

Posted: Thu Jun 14, 2018 6:45 am
by lorenfb
WetEV wrote:
lorenfb wrote: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.

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

Posted: Thu Jun 14, 2018 6:45 am
by webeleafowners
So when they refer to the battery capacity level gauge are they reffering to the 12 health bars on the right?

I know. Rookie question.

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

Posted: Thu Jun 14, 2018 6:46 am
by lorenfb
webeleafowners wrote:So when they refer to the battery capacity level gauge are they reffering to the 12 health bars on the right?

I know. Rookie question.


Yes.

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

Posted: Thu Jun 14, 2018 6:47 am
by webeleafowners
lorenfb wrote:
webeleafowners wrote:So when they refer to the battery capacity level gauge are they reffering to the 12 health bars on the right?

I know. Rookie question.


Yes.


Tanks dude.