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Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:14 pm
by wiltingleaf
Nissan has agreed to repurchase my car under AZ Lemon Law. Check out my blog for additional information.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:15 pm
by smkettner
TickTock wrote: This data is not LA4, but rather a 32.2A discharge rate to better match 55mph discharge rate.
Does this imply faster driving and spirited acceleration will degrade the battery significantly faster?

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:18 pm
by klapauzius
wiltingleaf wrote:Nissan has agreed to repurchase my car under AZ Lemon Law. Check out my blog for additional information.
Congrats! I think this should be a solution for everyone affected.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:30 pm
by jspearman
wiltingleaf wrote:Nissan has agreed to repurchase my car under AZ Lemon Law. Check out my blog for additional information.
Curious to see what the final number turns out to be. I'd take that check and go buy a Volt and invite a news crew along.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:39 pm
by gaswalla
wiltingleaf wrote:Nissan has agreed to repurchase my car under AZ Lemon Law. Check out my blog for additional information.
Great news! Congratulations, and I hope others can reach similar closure.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 2:44 pm
by TickTock
smkettner wrote:
TickTock wrote: This data is not LA4, but rather a 32.2A discharge rate to better match 55mph discharge rate.
Does this imply faster driving and spirited acceleration will degrade the battery significantly faster?
No. This doesn't (at least not directly). The additional loss of capacity caused by the higher discharge rate is just due to the additional I2R losses inside the battery - not permanent damage. If you drive slowly you will get more kWh out of your battery then if you drive fast. I got to see a graph of this effect too. At 90mph, a new battery pulls 40kW and will lose 5% of the battery capacity to i2r losses in the battery.

That said, driving faster *does* require more energy per mile just due to wind drag --> more charge/discharge cycles per mile --> more degradation per mile.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 3:01 pm
by wishboneash
TickTock wrote:
smkettner wrote:
TickTock wrote: This data is not LA4, but rather a 32.2A discharge rate to better match 55mph discharge rate.
Does this imply faster driving and spirited acceleration will degrade the battery significantly faster?
No. This doesn't. The additional loss of capacity caused by the higher discharge rate is just due to the additional I2R losses inside the battery - not permanent damage. If you drive slowly you will get more kWh out of your battery then if you drive fast. I got to see a graph of this effect too. At 90mph, a new battery pulls 40kW and will lose 5% of the battery capacity to i2r losses in the battery.

That said, driving faster *does* require more energy per mile just due to wind drag --> more charge/discharge cycles per mile --> more degradation per mile.
I don't quite agree. High current into or out of the battery will stress the battery more besides the IR drop issue that reduces power. There are papers on "intercalation stress" on Li-ion batteries, but not being a electrochemical engineer, I don't know how it applies to these batteries. However, I can envision high temperatures within the battery, electromigration effects etc. which could cause some damage over time (just like the exposure to high ambient temps). I prefer not to drive aggressively to mitigate this possibility and since I own and not lease, I am not taking any chances. I have not seen much degradation in capacity yet.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 4:55 pm
by JRP3
As I recall intercalation happens on charge and de-intercalation happens on discharge, and I believe the intercalation stress is only a concern during charge, and why batteries can usually put out a higher discharge rate than a charge rate.

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 5:45 pm
by azdre
Nissan is also going to buy our car back at standard lemon law repurchase terms. We were told of this intent (verbally only) a few days before the range test (9/11), and debated whether to say anything. We really couldn't jeopardize our chance at the buyback so we decided to keep quiet. We were very skeptical at whether they would actually follow through and were given no details at that time.

We followed the dispute resolution process as outlined in the warranty manual... to the tee. So if someone wants to know how we did it, tell them to RTFM! :-)

She gets returned on Tuesday at 9am. This will put this to an end for us, but we're still here to help anyone else get the resolution they desire. If anyone has an idea of an offset for all of the bad mojo I've given to EVs, let me know. I want them to be mainstreamed, but I'm not willing to throw $33,000 out the window for it to happen.

We'll have an update on KPHO (probably tonight @10pm). http://www.kpho.com/" onclick="window.open(this.href);return false;

Re: Early Capacity Losses-Was(Lost a bar...down to 11)

Posted: Wed Sep 26, 2012 6:31 pm
by jspearman
azdre wrote:Nissan is also going to buy our car back at standard lemon law repurchase terms. We were told of this intent (verbally only) a few days before the range test (9/11), and debated whether to say anything. We really couldn't jeopardize our chance at the buyback so we decided to keep quiet. We were very skeptical at whether they would actually follow through and were given no details at that time.

We followed the dispute resolution process as outlined in the warranty manual... to the tee. So if someone wants to know how we did it, tell them to RTFM! :-)

She gets returned on Tuesday at 9am. This will put this to an end for us, but we're still here to help anyone else get the resolution they desire. If anyone has an idea of an offset for all of the bad mojo I've given to EVs, let me know. I want them to be mainstreamed, but I'm not willing to throw $33,000 out the window for it to happen.

We'll have an update on KPHO (probably tonight @10pm). http://www.kpho.com/" onclick="window.open(this.href);return false;
Whoa, two in one day! Looks like the logjam might be breaking.