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LTLFTcomposite
Posts: 4780
Joined: Fri Apr 23, 2010 6:06 pm
Delivery Date: 10 Dec 2011
Leaf Number: 5926
Location: Central FL

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 4:37 am

SanDust wrote:
LTLFTcomposite wrote:
SanDust wrote:You can BTW extend for six months assuming it's a Nissan lease.
Whatchutalkinboutwillis?
You can extend the lease for six months at the same rate.
And the residual drops accordingly?
I leased for 36 months specifically to coincide with the bumper to bumper warranty. My luck some other expensive repair would pop up in that time frame (didn't someone here say they had a headlight go bad and it was nearly a grand to replace it?) so I probably wouldn't extend but good to know it's an option.
LTL
White 2012 SV delivered 10 Dec 2011 returned 25 Nov 2014 replaced with stopgap ICE Sentra
[35 months] [35K miles] [9 Bars]
2013 Volt replaced after 36 months/30k miles with ICE Rogue
2016 SV-adjacent May 2016 lost 4th bar March 2018

DaveinOlyWA
Posts: 15067
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 7:29 am

i dont think its outrageous to have a temporary loss in extreme temps which does happen in cold and hot. i do not have access to 21 Kwh in winter like i do in Summer. i tested that theory twice. once before the GID, once after and the results were probably temp related since i got access to just over 19 Kwh once and just under 19 Kwh the 2nd time. so the winter hit is less performance and less capacity.

so to have the same but to a lesser degree for Summer i can believe. problem with that i see. it would appear that a portion of the summer loss is permanent and likely to be cumulative.

i expected to have at least 5% after a year and up to 10% degradation after 18 months. i thought there would be a big chunk lost at first (still do) and then it would taper off to 1-2 % a year ending at 20% after 5

so could have been

year 1; 10% lost
year2-5 2% lost total 20%

or

year 1; 15% loss
year 2-5; 1% loss total 20%

now that i have not seen any real loss yet. i expect when it starts it will be 10-15% that everyone else is seeing before it levels off. for those few who are seeing more. that might be temporary due to the heat.
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 13,705 mi, 93.41% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

klapauzius
Posts: 1658
Joined: Thu Feb 24, 2011 4:19 pm
Delivery Date: 25 Jan 2011
Leaf Number: 0197
Location: Seattle, Wa

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 10:48 am

DaveinOlyWA wrote:i dont think its outrageous to have a temporary loss in extreme temps which does happen in cold and hot. i do not have access to 21 Kwh in winter like i do in Summer. i tested that theory twice. once before the GID, once after and the results were probably temp related since i got access to just over 19 Kwh once and just under 19 Kwh the 2nd time. so the winter hit is less performance and less capacity.

so to have the same but to a lesser degree for Summer i can believe. problem with that i see. it would appear that a portion of the summer loss is permanent and likely to be cumulative.

i expected to have at least 5% after a year and up to 10% degradation after 18 months. i thought there would be a big chunk lost at first (still do) and then it would taper off to 1-2 % a year ending at 20% after 5

so could have been

year 1; 10% lost
year2-5 2% lost total 20%

or

year 1; 15% loss
year 2-5; 1% loss total 20%

now that i have not seen any real loss yet. i expect when it starts it will be 10-15% that everyone else is seeing before it levels off. for those few who are seeing more. that might be temporary due to the heat.
I think the mechanisms for heat and cold are different. Whenever Thermodynamics is involved,
things are irreversible.

Understand that the higher/lower power/cap relationship between warm and cold is due to the normal battery chemistry going faster/slower at higher/lower temps. That is the normal function
of the battery. These changes take place on a rather fast timescale (i.e. however long it takes the battery pack to reach a given temperature, a few hours maybe).

Degradation is a totally different animal, that is the chemical process that destroys, if my understanding is correct, the electrodes of the battery. I takes place on a timescale of several years ( or so we hope) AND it is, unlike the normal battery operation, NON-reversible.
So hot temps speed this decay up, low temps slow it down, but ill goes in just one direction.

Put a rotten steak in the freezer and it wont become fresh and tasty again. :D

It might be however that there is an artificial intervention involved in the process, TickTocks cap vs temperature data indicate an almost linear relationship between temperature and capacity, but opposite to what you would expect from chemistry. So maybe the BMS is doing something...?

klapauzius
Posts: 1658
Joined: Thu Feb 24, 2011 4:19 pm
Delivery Date: 25 Jan 2011
Leaf Number: 0197
Location: Seattle, Wa

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 10:56 am

turbo2ltr wrote:If everyone wants to chip in for my electric bill, I'll charge my car in my air conditioned shop for the next week and see if I get a bar back.. lol
I think this test would work within the time frame to cool the battery pack to whatever ambient temperature your workshop has.

So here is the experiment:

1) Set your workshop to various temps, e.g. 65-70-75-80-85-90,

2) measure the battery pack temperature, when it reaches the set temperature on the thermostat, charge to full

3) measure gids (or true capacity if you have access to more sophisticated measures)

4) plot gids/cap vs. temps.

You could try one temperature setting each day. If the BMS would somehow reduce capacity because of higher temperatures, this should show it.

The thermodynamic process that destroys the battery is of course irreversible and cold temps merely slow it down, but artificial interventions could create the illusion of temporary loss.
It seems like grasping after straws though...

jspearman
Posts: 244
Joined: Sun Aug 21, 2011 4:04 pm
Delivery Date: 20 Aug 2011
Leaf Number: 5954
Location: Phoenix, AZ

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 12:03 pm

Thanks for the thoughtful post, Shrink. I am in a similar boat, since this is my wife's daily driver and she is reluctant to trade the car for another. Are there any women on this forum?

I'm interested to see what kind of depreciation that car dealers assign to the loss of bars after trading electric cars becomes more common. I think you are right that they likely had no idea what they were looking at, except a shiny electric car with low mileage. I think we will hang on until Nissan proposes some kind of solution.

leafkabob
Posts: 410
Joined: Fri Dec 03, 2010 5:47 am
Delivery Date: 09 Sep 2015
Leaf Number: 1827
Location: Central Phoenix

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 12:09 pm

jspearman wrote:Thanks for the thoughtful post, Shrink. I am in a similar boat, since this is my wife's daily driver and she is reluctant to trade the car for another. Are there any women on this forum?

I'm interested to see what kind of depreciation that car dealers assign to the loss of bars after trading electric cars becomes more common. I think you are right that they likely had no idea what they were looking at, except a shiny electric car with low mileage. I think we will hang on until Nissan proposes some kind of solution.
Same boat here too. Our Leaf is my wife's daily driver and she is very reluctant for me to push Nissan to any resolution that would cause her to lose the leaf. She said the thought of going back to an ICE turns her stomach. It does me too, which makes this a real quandry.
Kelly

2011 White SL-e (sold back to Nissan on 01/10/2013)
2011Silver SL with new lizard battery purchased used on 9/9/2015
2018 Tesla Model 3 received 4/27/2018

DaveinOlyWA
Posts: 15067
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 2:15 pm

klapauzius wrote: I think the mechanisms for heat and cold are different. Whenever Thermodynamics is involved,
things are irreversible.

Understand that the higher/lower power/cap relationship between warm and cold is due to the normal battery chemistry going faster/slower at higher/lower temps. That is the normal function
of the battery. These changes take place on a rather fast timescale (i.e. however long it takes the battery pack to reach a given temperature, a few hours maybe).

Degradation is a totally different animal, that is the chemical process that destroys, if my understanding is correct, the electrodes of the battery. I takes place on a timescale of several years ( or so we hope) AND it is, unlike the normal battery operation, NON-reversible.
So hot temps speed this decay up, low temps slow it down, but ill goes in just one direction.

Put a rotten steak in the freezer and it wont become fresh and tasty again. :D

It might be however that there is an artificial intervention involved in the process, TickTocks cap vs temperature data indicate an almost linear relationship between temperature and capacity, but opposite to what you would expect from chemistry. So maybe the BMS is doing something...?
right and the issue we probably have here is the battery management not working well in temps hotter than expected.

suppose, we charge to 100% of available capacity in a garage. its 85 or whatever. we leave garage hit the 110º pavement. we drive just a few miles, SOC still near enough to 100% that the additional heat created pushes the battery over its limits. granted, just a little. but that little tiny bit is lost capacity, never to return. this can add up to the significant loss AZ'ers are seeing over time.

that is one probably mechanism. the other is Battery management itself. it is out and about, temps are high. charging starts and battery management purposefully restricts access to the full capacity as a protection measure against the still high temps. so instead of going to the 100% of available capacity, it stops short at say 90% to give that extra head room in case temps spike up again. this will come back.
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 13,705 mi, 93.41% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

User avatar
Kataphn
Posts: 753
Joined: Thu Jun 03, 2010 10:57 am
Delivery Date: 13 Jun 2013
Location: Los Angeles, CA

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 2:52 pm

jspearman wrote: Are there any women on this forum?
Yes, woman here...there are several of us that post from time to time.
Delivered: May 3, 2011
VIN: 1467 made 3-7-11
SL, Blue, eTec trim, EV project Blink
[purchased] as of 11-1-13: 25,000: 11 bars
Also have a PiP

LEAFfan
Posts: 4828
Joined: Fri Apr 23, 2010 6:08 pm
Delivery Date: 08 Jun 2011
Leaf Number: 1855
Location: Phoenix Area

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 2:59 pm

There are drivers now that are close to losing their third bar so I highly doubt if these bars are going to come back when the weather cools. The cooler weather (winter) may slow down the degradation until the heat comes again (it only takes 87F or higher to start the larger degradation process and we have those temps most of the year), but another bar will disappear during the summer and the degradation will once again accelerate.
2013 LEAF SV Del. 2/28/13
2013 LEAF World Record for Most Miles Driven On One Charge-188 miles/8.8 m/kW h
4.8 kW DC PV ($ .91/W fully installed)/ Dec., 2010

shrink
Posts: 360
Joined: Sun Aug 07, 2011 11:21 pm
Delivery Date: 26 Jun 2012
Leaf Number: 21842
Location: Phoenix, AZ

Re: Turning Over a New LEAF: My Response to a Lost Capacity

Sat Jun 30, 2012 3:23 pm

Some new data:

Leaffan was generous enough to come over and take some reading with his Scan Gauge today.

On the new 2012 LEAF that now has about 100 miles on it, a 100% charge resulted in 95.3%.

My 2011 LEAF on 5/25/2012 had 85.7% on the same gauge. I lost my 1st bar on 6/21/2012. I believe leafkabob lost his 1st capacity bar one day after an 81.1% reading on his LEAF.

95.3% - 81.1% = 14.2%

So, that's just about the 15% capacity loss listed in the service manual.
Last edited by shrink on Sat Jun 30, 2012 5:44 pm, edited 1 time in total.
2011 LEAF (Sold) | 2012 Volt (Sold) | 2012 LEAF (Lease Ended) | 2010 Tesla Roadster #501 | 2013 Tesla Model S #9001 | 6.827 kW SunPower PV System

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