webeleafowners
Well-known member
Thank you to Orient Express for the above post. It is very clear. I'll wait for the message.
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.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.
dwl said: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.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.
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).
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?
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".
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?"
webeleafowners said: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.
lorenfb said:webeleafowners said: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.
lorenfb said:Hopefully, this "fix"
doesn't fully reset all the battery parameters, e.g. SOH == 95 - 100% after the "fix".
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.
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
LTLFTcomposite said:Sounds like they are reprogramming it so the bars don't drop so fast. Big money savings for Nissan, owners lose out.
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.
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?
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.
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 ??
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