Capacity Loss on 2011-2012 LEAFs

[DaveEV]

That reference is to the "old" Service Manual. That chart has been replaced by a graph in the April 2011 Revision of the LEAF Service Manual and the temperature ranges given are different:

5 Bars: -3C (27F) to 27C (81F)
6 Bars: 10C (50F) to 38C (100F)

Interesting that this graph shows the hysteresis that would keep the bars from bouncing around too much - there's a 31F overlap which is quite large.

What's weird is that my car currently toggles between 5-6 bars if it doesn't get too warm during the day, and for sure I know it's not getting below 50F - it's probably not getting below 65F so it would be interesting to know how it chooses between overlapping bars.

 

[RegGuheert]

What's weird is that my car currently toggles between 5-6 bars if it doesn't get too warm during the day, and for sure I know it's not getting below 50F - it's probably not getting below 65F so it would be interesting to know how it chooses between overlapping bars.

Yeah, I don't think those bars are meant to apply to a car in one given condition. In other words, I don't think you can cover the entire bar in one day, but you may be able to see that over the life of the battery.

Frankly, I think the original chart was more useful for a new LEAF, but it may not apply later in the car's life.

 

[smkettner]

That reference is to the "old" Service Manual. That chart has been replaced by a graph in the April 2011 Revision of the LEAF Service Manual and the temperature ranges given are different:

5 Bars: -3C (27F) to 27C (81F)
6 Bars: 10C (50F) to 38C (100F)

Interesting that this graph shows the hysteresis that would keep the bars from bouncing around too much - there's a 31F overlap which is quite large.

What's weird is that my car currently toggles between 5-6 bars if it doesn't get too warm during the day, and for sure I know it's not getting below 50F - it's probably not getting below 65F so it would be interesting to know how it chooses between overlapping bars.

I will have 6 bars in the morning in a 72-74 garage charging to 80% by 6a. It may sit in the sun at work with temps around 66-68 in the morning and it drops to 5 bars by lunch time. I just do not see how that wide range hyteresis is actually working the way it implies.

I think I can sense a drop in range and been getting 9 bars at 80% for at least a month on and off. No GID meter and I am hoping I am not the first along the mild coast to lose that first capacity bar. Time will tell.

 

[SanDust]

So the question on everyone's mind is whether future losses of bars will happen more quickly or more slowly than the second bar. Many believe Nissan's claim that capacity losses slow with time. I am not convinced.

That's how the batteries work. We don't have the charts for the Leaf batteries but we do for the Tesla Model S batteries. 20% loss over the first 300 cycles and 30% over the first 500 cycles. But then the curve flattens and you get maybe another 5% loss at 2000 cycles.

Heat accelerates he process but it doesn't change it. Expect to see Leafs in milder climate reporting losses sooner or later.

 

[RegGuheert]

That's how the batteries work. We don't have the charts for the Leaf batteries but we do for the Tesla Model S batteries. 20% loss over the first 300 cycles and 30% over the first 500 cycles. But then the curve flattens and you get maybe another 5% loss at 2000 cycles.

As I said, that is how batteries work when losses are dominated by the effects of cycling.

Heat accelerates he process but it doesn't change it.

Take away the cycling and you still have calendar losses, so I would say heat has its own loss mechanism. Granted, I haven't seen many studies of calendar losses without cycling (of course there are a few cycles to measure the battery), but the one I have seen on chemistry similar to the Tesla shows calendar losses ACCELERATING once you pass a 15% drop in capacity. Do you have a study of any Li-ion battery calendar capacity losses (without cycling) which shows the opposite?

Unfortunately, that is the regime the LEAF batteries in Phoenix are being operated in: calendar losses dominating over cycling losses. Does the LEAF have the same shape for its calendar losses? I don't know, but in absence of evidence to the contrary, I will suspect that it does. None of the anecdotal evidence posted on this forum to date leads me to believe otherwise.

 

[Boomer23]

I posted this same post on the "I Want my 281" thread, but thought I'd post it here as well.


I just took my LEAF to turtle in the interest of increasing the general knowledge base about pack capacity reduction and actual range impact.

My last (and first) turtle experience was on April 14, 2011, two weeks after bringing the car home, and before I had a Gid meter. Range from 100% charge to turtle was 86.5 miles at an indicated energy economy on the main dash of 4.0 mi/kWh. Turtle announcement came on about .3 miles before I stopped the car.

Today's readings are 75.0 miles range at 4.1 mi/kWh. Gid reading at the end of the run was 5 Gids (1.7%). Turtle indicator lit as I was pulling into the garage. Gid reading at the beginning of day was 258 (91.8%).

So I'm calculating a range reduction of 13.3%, minimum. Actual range reduction is probably very slightly more since today's mi/kWh was slightly higher and I stopped the car slightly sooner. Still, my 75 mile range is slightly better than the EPA rating for the LEAF.

Other data on my car:
Mieage: 14,372 mi
Age: Car delivered 3/30/11, slightly more than 15 months old.
I have not lost a capacity bar.
Most frequent charging percent: 100% until mid-May, 2012, when I changed to 80% charging most frequently.
Quick Charges: twice
Location: Coastal Southern Calif
Overall energy efficiency measured at wall: 3.22 mi/kWh, lifetime

I generally got a full 280 to 281 Gids at full charge until early May, 2012, when I started to notice a decline in Gids.

Most recent three Gid readings at full charge were 257 (91.4%), 266 (94.6%) and 258 (91.8%).
Max capacity loss by Gid reading: 8.5%

Charging energy required to charge to 100% from turtle on April 14, 2011 measured by TED system: 26.1 kWh
I'll update this thread tomorrow with charging energy after recharging to 100%.
Update: full charge overnight went to 265 Gid (94.3%) and took 21.7 kWh from the wall.

So how do we measure capacity loss?
75 miles to turtle vs. 86.5 miles when the car was new? 13.3% capacity loss?
Averaging Gids to full charge? Mean of 263 Gid (includes most recent charge) on three consecutive days full charges vs 281 Gid: 6.4% capacity loss?
Energy from wall to recharge from turtle? 21.7 kWh vs 26.1 when new: 16.9% capacity loss?

I guess I'd go with the actual driving range figure.

 

[mkjayakumar]

In little over a month you lost over 24 Gids ?

 

[Boomer23]

Two months, actually.

 

[mkjayakumar]

That makes me feel better

 

[vrwl]

Edit: updated the wiki with 4 other people (ecoobsessive, Leafwing, GerryAZ, and jhm614) who weren't already in there but were on this list

added djchrispaul to this list, also added him to the wiki, he posted his loss of a bar on another thread which is linked to his name in the wiki

1. Azdre & Opossum - April 26, 2012. 16.6K miles/13 months ownership. Phoenix (2nd bar loss reported 6/14/2012 @~19K miles)
2. bturner - May 12, 2012. 13.6K/12 months. Phoenix
3. turbo2ltr - May 18, 2012. 13K/15 months. Phoenix (2nd bar loss reported 6/29/2012)
4. TickTock - May 20, 2012. 14K/12 months Phoenix
5. Volusiano - May 20, 2012. 16.5K/12 months. Phoenix
6. Mark13 - May 22, 2012. 15.7K/12 months. Phoenix (2nd bar loss reported 7/1/2012)
7. Leafkabob - May 26, 2012. 9.5K/12 months. Phoenix
8. Cyellen - June 7, 2012. 10.2K/ 14 months. Phoenix
9. RickS - June 10, 2012. 11.3K/13 months. Phoenix
10. Pipcecil - June 17, 2012. 20.2K/12 months. Dallas, Texas
11. Phxsmiley - June 17, 2012. 13.7K/10 months. Phoenix
12. AZknauer - June 17, 2012. 9.2K/13.5 months. Phoenix
13. Myleaf - June 19, 2012. 13.3K/14 months. Phoenix
14. johndoe74 - June 5, 2012. 13.5K/ 9 months. Phoenix
15. Matt Ferris - June 20, 2012. 15K/ 12 months. Dallas, Texas
16. Shrink - June 21, 2012. 10.2K/ 10.5 months. Phoenix (sold that Leaf, replaced w/leased '12 Leaf)
17. ravi100 - June 24, 2012. 13.1K/ 13.5 months. Southlake, Texas (no longer has Leaf)
18. ev4me - approx. June 1, 2012. 7K/ 15 mos. Phoenix (Dropped 2 bars)
19. jspearman - June 28, 2012, ?/10.5 months. Phoenix
20. Leafwing - July 05, 2012, 13.5K/15 months, Plano, TX.
21. GerryAZ - July 05, 2012, ?/?, Phoenix
22. ecoobsessive - July 6, 2012, 13K/13 months, San Antonio, TX
23. jhm614 - May 15, 2012, 25K/14.5 months, Arlington, TX (2nd bar loss reported on 7/7/2012)
24. djchrispaul - June 22, 2012, 4.3k/9months, Palm Springs, NV

Not reported by owner, but by others:
1. Opossum reported knowing of another car in Phoenix that has lost 2 bars.
2. Leafkabob reported a street encounter with a Leaf owner who stated he lost a bar after about a year.
3. Skywagon approx. May, 2012. Phoenix (supposedly no longer has Leaf)

 

[HXGuy]

Is that correct, Palm Springs, NV or should it be CA?

Also, wow, one bar lost at only 4,300 miles/9 months?

 

[vrwl]

Edit: updated the wiki with 4 other people (ecoobsessive, Leafwing, GerryAZ, and jhm614) who weren't already in there but were on this list

added djchrispaul to this list, also added him to the wiki, he posted his loss of a bar on another thread which is linked to his name in the wiki

Well, after reading more of the thread where djchrispaul discusses his "bar loss", I'm removing him from the list and from the wiki. He's lost a GOM bar, not a capacity bar.

1. Azdre & Opossum - April 26, 2012. 16.6K miles/13 months ownership. Phoenix (2nd bar loss reported 6/14/2012 @~19K miles)
2. bturner - May 12, 2012. 13.6K/12 months. Phoenix
3. turbo2ltr - May 18, 2012. 13K/15 months. Phoenix (2nd bar loss reported 6/29/2012)
4. TickTock - May 20, 2012. 14K/12 months Phoenix
5. Volusiano - May 20, 2012. 16.5K/12 months. Phoenix
6. Mark13 - May 22, 2012. 15.7K/12 months. Phoenix (2nd bar loss reported 7/1/2012)
7. Leafkabob - May 26, 2012. 9.5K/12 months. Phoenix
8. Cyellen - June 7, 2012. 10.2K/ 14 months. Phoenix
9. RickS - June 10, 2012. 11.3K/13 months. Phoenix
10. Pipcecil - June 17, 2012. 20.2K/12 months. Dallas, Texas
11. Phxsmiley - June 17, 2012. 13.7K/10 months. Phoenix
12. AZknauer - June 17, 2012. 9.2K/13.5 months. Phoenix
13. Myleaf - June 19, 2012. 13.3K/14 months. Phoenix
14. johndoe74 - June 5, 2012. 13.5K/ 9 months. Phoenix
15. Matt Ferris - June 20, 2012. 15K/ 12 months. Dallas, Texas
16. Shrink - June 21, 2012. 10.2K/ 10.5 months. Phoenix (sold that Leaf, replaced w/leased '12 Leaf)
17. ravi100 - June 24, 2012. 13.1K/ 13.5 months. Southlake, Texas (no longer has Leaf)
18. ev4me - approx. June 1, 2012. 7K/ 15 mos. Phoenix (Dropped 2 bars)
19. jspearman - June 28, 2012, ?/10.5 months. Phoenix
20. Leafwing - July 05, 2012, 13.5K/15 months, Plano, TX.
21. GerryAZ - July 05, 2012, ?/?, Phoenix
22. ecoobsessive - July 6, 2012, 13K/13 months, San Antonio, TX
23. jhm614 - May 15, 2012, 25K/14.5 months, Arlington, TX (2nd bar loss reported on 7/7/2012)

Not reported by owner, but by others:
1. Opossum reported knowing of another car in Phoenix that has lost 2 bars.
2. Leafkabob reported a street encounter with a Leaf owner who stated he lost a bar after about a year.
3. Skywagon approx. May, 2012. Phoenix (supposedly no longer has Leaf)

 

[vrwl]

Is that correct, Palm Springs, NV or should it be CA?

Also, wow, one bar lost at only 4,300 miles/9 months?

Heh, my bad... CA. But see my previous post, he's off the list anyway. He lost a GOM bar but not a capacity bar (yet).

Edit: And now that I've finally plowed through all the pages in that thread, he traded it in on a leased 2012 Leaf, so it's someone else's problem now.

 

[mwalsh]

Is that correct, Palm Springs, NV or should it be CA?

Also, wow, one bar lost at only 4,300 miles/9 months?

Heh, my bad... CA. But see my previous post, he's off the list anyway. He lost a GOM bar but not a capacity bar (yet).

Edit: And now that I've finally plowed through all the pages in that thread, he traded it in on a leased 2012 Leaf, so it's someone else's problem now.

Good. Because, perverse though it may sound, I want to be the first CA resident to loose a capacity bar.

 

[Stoaty]

Good. Because, perverse though it may sound, I want to be the first CA resident to loose a capacity bar.

Some people will look for any chance to be "first", dubious though the honor may be in this case. :lol:

 

[DesertDenizen]

Good. Because, perverse though it may sound, I want to be the first CA resident to loose a capacity bar.

Some people will look for any chance to be "first", dubious though the honor may be in this case. :lol:

I fear I may be the first from Tucson to lose a bar. I don't wanna join that club!

 

[Stoaty]

I fear I may be the first from Tucson to lose a bar. I don't wanna join that club!

Do you have a recent Gid reading after 100% charge, and if so, what is it? Don't recall whether you have a Gid-o-meter or access to one. Apologies in advance if you already posted that number; I'm not going to read through 110 pages of this thread to find out.

 

[DesertDenizen]

I fear I may be the first from Tucson to lose a bar. I don't wanna join that club!

Do you have a recent Gid reading after 100% charge, and if so, what is it? Don't recall whether you have a Gid-o-meter or access to one. Apologies in advance if you already posted that number; I'm not going to read through 110 pages of this thread to find out.

No, no GID reading, I wonder if anyone in Tucson has one. I have never seen a post from someone else from Tucson. But as an 80% charge sometimes gives me 9 bars from what I have read on this great forum that does not augur well.

 

[LEAFer]

Suggestion: If you live in an "affected area" and have a GID meter or access to one temporarily, post your 100% charge GID # in your signature.

I did. We don't have a GID meter, but I used the one from Tony's LEAF on our LEAF while I had his here at home. I don't really live in an "affected area", although we have pretty hot 3-4 month summers. However, our summer last year was a lot milder than any one before in several years. This year it's been "mild" so far, but the duration of the heat spells is getting longer. It still cools (60F) at night, so I can't claim it's anything like AZ here. I would argue, though, that we're hotter than mwalsh ... so, let's see what happens :|

 

[DarkDave]

Add me to the 11 bar list. I should have reported it sooner on this thread.

I live in the Phoenix area, and I saw my Leaf drop to 11 bars around June 15th at ~8500 miles and ownership time of 14.5 months.