mkjayakumar
Well-known member
I am not sure replacing a few cells is the right solution. That will give you a few more months of better range only to find yourself in the same state again..I
Herm said:You guys might have a few bad modules (or one) bringing the whole pack down prematurely, Nissan might be becoming receptive to fixing these cases now that the brown stuff has hit the fan.. it cant be inexpensive to fix. You will never know unless they tell you a module is significantly lower than the rest.
LEAFfan said:Herm said:You guys might have a few bad modules (or one) bringing the whole pack down prematurely, Nissan might be becoming receptive to fixing these cases now that the brown stuff has hit the fan.. it cant be inexpensive to fix. You will never know unless they tell you a module is significantly lower than the rest.
It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
Joeviocoe said:From what I've heard, there is a small fan inside the sealed pack that keeps the temperature consistent to avoid hot spots...
As we have heard in one of the many interviews recently, Nissan can track the state and health of the battery pack through CarWings very granularly, supposedly down to the cell level. If any of the affected Leafs had a bad module or two, it's possible that a repair would have been attempted. Additionally, Randy indicated that a cell-pair voltage test was conducted on his car and revealed that the pack was Normal (TM).LEAFfan said:It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
wiltingleaf said:He also showed me the voltage output of all 96 cells of the battery were in specification. I tried to explain to him that the output voltage of a battery means nothing if it can only sustain that for a limited amout of time. He just told me this shows there is not obvious issues with the battery and therefore the car is working "normally".
TonyWilliams said:Joeviocoe said:From what I've heard, there is a small fan inside the sealed pack that keeps the temperature consistent to avoid hot spots...
Not true. There was in prototypes, but not production LEAFs.
While I agree that it's generally the entire pack that degrades, I think you really need to go below LBW to get a better picture of weak cells.LEAFfan said:It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
drees said:While I agree that it's generally the entire pack that degrades, I think you really need to go below LBW to get a better picture of weak cells.
In fact, if I'm understanding Nissan's test procedures - you are more likely to trigger a case for cell replacement with the lowest SOC possible since that's most likely to generate the highest differences in cell voltage.
drees said:While I agree that it's generally the entire pack that degrades, I think you really need to go below LBW to get a better picture of weak cells.LEAFfan said:It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
In fact, if I'm understanding Nissan's test procedures - you are more likely to trigger a case for cell replacement with the lowest SOC possible since that's most likely to generate the highest differences in cell voltage.
Weak cells still charge to the same voltage because they are top balanced by the BMS, which means they are unbalanced at the bottom. Weak cells will show increased voltage drop near the end of discharge since they have less capacity. Reading the voltage of each cell, or cell pair, during discharge will point out the weak cells.DaveinOlyWA said:what happens is weaker cells will have greater voltage drop. essentially the knee appears to move to a fairly high voltage level (this is reason why degraded cells still charge to 393 volts)
Dave, did the ZENN have a sophisticated cell balancing scheme with shunts across each cell as is employed in the LEAF?DaveinOlyWA said:now with lead acid (granted much different but still a battery) i saw weak cells very early in my ZENN. problem with "pack mentality" is batteries work the same way.
RegGuheert said:Dave, did the ZENN have a sophisticated cell balancing scheme with shunts across each cell as is employed in the LEAF?DaveinOlyWA said:now with lead acid (granted much different but still a battery) i saw weak cells very early in my ZENN. problem with "pack mentality" is batteries work the same way.
leiko49 said:2nd bar loss this morning, first bar reported about 2 months ago (in Wiki). 10,100 miles! Given my loss of battery capacity, I might just drop my yearly Leaf mileage (due to range loss, and lack of opportunity to charge on the fly) from 10K a year to the Nissan normed average of 7,500. At least I'll know I am now normal.
Your truly magic graph will not grant me the magick I seek, to return to the day when the car was anew, and a 107 number graced my fully charged GOM (Nissan pseudo magick), minus the 2% a year promise. I was naive back then, I know that now. But still, I dream.TonyWilliams said:leiko49 said:2nd bar loss this morning, first bar reported about 2 months ago (in Wiki). 10,100 miles! Given my loss of battery capacity, I might just drop my yearly Leaf mileage (due to range loss, and lack of opportunity to charge on the fly) from 10K a year to the Nissan normed average of 7,500. At least I'll know I am now normal.
Fresh off the presses:
Use this 75% chart for a battery that has 10 of 12 capacity bar segments.
FWIW, I wanted to amend my statements about the best class action settlement I've gotten. Previously it was for http://www.girardgibbs.com/Prius.asp" onclick="window.open(this.href);return false;, where I received a check for the cost of 2 HID bulbs (~$110 total, IIRC) bought from Amazon, even though I was a bit past the time and mileage provided by the settlement's warranty extension when one of my HID bulbs started failing.mwalsh said:theaveng said:I've gotten close to 1000 dollars from class-action lawsuits. $25 from the CD/record Company cartel case, $85 from the paypal case, and 800 from the Equinox MLM class-action case.turbo2ltr said:2: The only people that win in class action lawsuits (or any for that matter) are the lawyers. IANAL, so I will not participate in any class action.
I'm getting $4500 (in an unrelated suit) as a named plaintiff, as are the other 7 named plaintiffs, after two years of back and forth in court. The class members who aren't named are getting $10 each. The lawyers are getting $3.5 million. I wouldn't peruse legal action like this again. The only plus side of it for me is that the company we sued is going to have to change the way they do business, which was very important to me personally.
We had Nissan do a cell test at full SOC and at VLBW. Variances were in tolerance both times.drees said:While I agree that it's generally the entire pack that degrades, I think you really need to go below LBW to get a better picture of weak cells.LEAFfan said:It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
In fact, if I'm understanding Nissan's test procedures - you are more likely to trigger a case for cell replacement with the lowest SOC possible since that's most likely to generate the highest differences in cell voltage.
azdre said:We had Nissan do a cell test at full SOC and at VLBW. Variances were in tolerance both times.drees said:While I agree that it's generally the entire pack that degrades, I think you really need to go below LBW to get a better picture of weak cells.LEAFfan said:It's very unlikely they have bad modules. In this kind of heat, it's the whole battery that degrades, not just a few cells or modules. When I was down about 10%, I thought that some cells went bad, but every one tested 'good' and I was given a copy of the whole report. At the time of the test, I was down to 2-3 fuel bars.
In fact, if I'm understanding Nissan's test procedures - you are more likely to trigger a case for cell replacement with the lowest SOC possible since that's most likely to generate the highest differences in cell voltage.
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