Capacity Loss on 2011-2012 LEAFs

[RegGuheert]

I've noticed that the gids tend not to "fly off" when driving on an 80% or 100% charge. Before it seemed like I'd drop 5-10 gids in the first half mile of driving, now it seems a bit more reasonable at a few gids.

Thanks for this comment! I think this is the first mention of an actual change in behavior due to the new firmware.

 

[TomT]

Mine returned to the original Gid behavior about two months after I got the P3227 update. This the first report I have heard of the bar behavior remaining...

I've noticed that the gids tend not to "fly off" when driving on an 80% or 100% charge. Before it seemed like I'd drop 5-10 gids in the first half mile of driving, now it seems a bit more reasonable at a few gids.

Thanks for this comment! I think this is the first mention of an actual change in behavior due to the new firmware.

 

[KJD]

Today was a 9 bar 80% charge. The temps here this morning were low 70's. GID count was 210.

Have not done a 100% charge for a while, guess I will do that this weekend. Not happy at 15,000 miles.

 

[TimLee]

You need to time your sale of the Leaf around getting the new battery pack ..I expect in 2 years to need a new battery replacement again, that is when I will sell the Leaf and buy a new one, as long as the same warranty is in use ...

I will be curios in 2015, what a 2011 Leaf will be worth with 56000 miles, and with a new battery pack ....

No guarantee you'll get a brand new battery pack under warranty in 2015 with 56000 miles on the vehicle. It is possible, but also a possibility Nissan will install a 9, 10, or 11 capacity bar battery pack.

 

[vrwl]

You need to time your sale of the Leaf around getting the new battery pack ..I expect in 2 years to need a new battery replacement again, that is when I will sell the Leaf and buy a new one, as long as the same warranty is in use ...

I will be curios in 2015, what a 2011 Leaf will be worth with 56000 miles, and with a new battery pack ....

Agreed, but if we move up north to the cooler climate, I may not ever get to the point where I qualify for a replacement battery pack.

 

[JeremyW]

Mine returned to the original Gid behavior about two months after I got the P3227 update. This the first report I have heard of the bar behavior remaining...

Well I got the update on 8/2 so I've got some time for the car to "revert" to it's old ways. I've already gone from ~61Ah to 59.2Ah. Before the update I was at 57Ah.

Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

 

[LEAFfan]

Mine returned to the original Gid behavior about two months after I got the P3227 update. This the first report I have heard of the bar behavior remaining...

Well I got the update on 8/2 so I've got some time for the car to "revert" to it's old ways. I've already gone from ~61Ah to 59.2Ah. Before the update I was at 57Ah.

Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

That recommendation was in the old manual and now they say multiple QCs are okay.

 

[scottf200]

<snip>Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

That recommendation was in the old manual and now they say multiple QCs are okay.

Seriously?
Is that because as the battery capacity drops they think people may need to do multiple QC's per day?
Or because they have the battery capacity warranty now and so they can easily just replace it?
Or I guess they have the $100/month battery lease deal for those that bought the LEAF so it is covered?

 

[smkettner]

IMO it is the heat from QC that kills the battery not the QC itself.
Best to just go 70% to build less heat and stop QC for the day if you see 7 temp bars. In AZ that might mean no summer QC
Just MHO.

 

[surfingslovak]

IMO it is the heat from QC that kills the battery not the QC itself.

Agreed, that's what I would assume as well. In time, we will learn how those Model S owners will fare. Isn't supercharging moving to 125 kW or 1.5 to 2C rate, depending on the battery pack size?

 

[TomT]

Since has TMS, it shouldn't be an issue...

IMO it is the heat from QC that kills the battery not the QC itself.

Agreed, that's what I would assume as well. In time, we will learn how those Model S owners will fare. Isn't supercharging moving to 125 kW or 1.5 to 2C rate, depending on the battery pack size?

 

[TonyWilliams]

Repetitive DC charging on the LEAF, even at relatively low SOC% in benign ambient temperatures will heat up the battery. BTDT.

The problem is that even if the battery is only heated 10F, it won't appreciably cool down before the next charge. Then only 10F is added, and so on.

The thermal mass of the battery will hold a lot of heat for a long time.

 

[DaveEV]

Mine returned to the original Gid behavior about two months after I got the P3227 update. This the first report I have heard of the bar behavior remaining...

Mine has also returned to normal. The first 10 GIDs or so fly off very quickly as usual.

I've already gone from ~61Ah to 59.2Ah. Before the update I was at 57Ah.

Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

Not necessarily. Considering your miles, 59 Ah doesn't look too bad. That's about 1 Ah every 2.4k miles. Assuming capacity loss rate stays the same, by the time you get to 22.5k miles (same as me) you'll lose another 2.5 Ah putting you at 56.5 Ah which is slightly higher than me and I've only QCd 4 times, never more than once a day with 2 of those times only ~10 minutes long and one of those two on a 25 kW QC which was limiting the charge rate.

 

[LEAFfan]

<snip>Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

That recommendation was in the old manual and now they say multiple QCs are okay.

Seriously?
Is that because as the battery capacity drops they think people may need to do multiple QC's per day?
Or because they have the battery capacity warranty now and so they can easily just replace it?
Or I guess they have the $100/month battery lease deal for those that bought the LEAF so it is covered?

Yes, seriously.

 

[LEAFfan]

Repetitive DC charging on the LEAF, even at relatively low SOC% in benign ambient temperatures will heat up the battery. BTDT.

The problem is that even if the battery is only heated 10F, it won't appreciably cool down before the next charge. Then only 10F is added, and so on.

The thermal mass of the battery will hold a lot of heat for a long time.

People need to keep in mind that most drivers aren't doing multiple QCs such as you have done. One or two a day with an hour or so in between isn't going to hurt the pack. Again, the most degradation is from high ambient temps over time. So when posters try to say it damages the pack, they need to quantify the number and time between the QC charges.

 

[shrink]

Since has TMS, it shouldn't be an issue...

IMO it is the heat from QC that kills the battery not the QC itself.

Agreed, that's what I would assume as well. In time, we will learn how those Model S owners will fare. Isn't supercharging moving to 125 kW or 1.5 to 2C rate, depending on the battery pack size?

I'm not so sure. Quoting from this article:

Moreover, electric car owners should refrain from doing too many “fast charges,” in which an EV battery can be recharged in under an hour.

”At high power, there is deformation of the material on a particle scale,” Cugnet said. “If you’re really in a hurry, it’s OK to do it a few times,” he said. “But most of the time, you should charge your car overnight.”

 

[JeremyW]

Mine returned to the original Gid behavior about two months after I got the P3227 update. This the first report I have heard of the bar behavior remaining...

Mine has also returned to normal. The first 10 GIDs or so fly off very quickly as usual.

I've already gone from ~61Ah to 59.2Ah. Before the update I was at 57Ah.

Oh and for those following along, here's living proof multiple qc's in a day is bad for your battery. :roll: Not surprising Nissan doesn't recommend more than one a day. I'm only at ~16,500 miles.

Not necessarily. Considering your miles, 59 Ah doesn't look too bad. That's about 1 Ah every 2.4k miles. Assuming capacity loss rate stays the same, by the time you get to 22.5k miles (same as me) you'll lose another 2.5 Ah putting you at 56.5 Ah which is slightly higher than me and I've only QCd 4 times, never more than once a day with 2 of those times only ~10 minutes long and one of those two on a 25 kW QC which was limiting the charge rate.

I lied, I'm at 58.8 now (checked today). Obviously, the heat is the bad part about QCing (mostly), and the majority of my charging is at home/work bla bla bla. I know when I took my car to 8 TBs (~47c) I dropped a whole Ah just from that event. I originally dropped 1.3 Ah or so and gained back the 0.3Ah. We'll see how the summer progresses... :roll:

 

[TonyWilliams]

I lied, I'm at 58.8 now (checked today). Obviously, the heat is the bad part about QCing (mostly), and the majority of my charging is at home/work bla bla bla. I know when I took my car to 8 TBs (~47c) I dropped a whole Ah just from that event. I originally dropped 1.3 Ah or so and gained back the 0.3Ah. We'll see how the summer progresses... :roll:

Quotes from Shrink's link at Design News

"Other factors also play into the life expectancy of lithium-ion batteries. The first of those factors -- temperature -- is the most important. Batteries that are exposed to high mean temperatures tend to degrade significantly faster than those in colder climates. “If you’re living in Abu Dhabi, the battery life will be much shorter than if you’re in a place that has colder winters,” Cugnet told us. “And if you have your car parked under the sun in Atlanta or Louisiana three months of every year, the battery won’t last 20 years.”"

"The wrong charging techniques can also shorten a battery’s life. Lithium-ion battery packs need to stay as close as possible to a 50 percent charge, he said, usually going no higher than 80 percent and no lower than 20 percent. Moreover, electric car owners should refrain from doing too many “fast charges,” in which an EV battery can be recharged in under an hour."

"”At high power (charging), there is deformation of the material on a particle scale,” Cugnet said. “If you’re really in a hurry, it’s OK to do it a few times,” he said. “But most of the time, you should charge your car overnight.”"

 

[keydiver]

What were your battery app readings (AHr, CAP%, Health, GIDs) when you lost your bar?

Honestly, I wasn't watching it that closely, but last time I checked 2 weeks ago I was just a hair over 85%. That was yesterday, and today they are:
Ahr: 55.73
CAP%: 84.12%
HEALTH: 81.13%
GIDS: 196 (69.8%)
All cells are actually rather tightly grouped, with only 17mv differential.

I did a 100% charge for the first time today since losing a bar:
AHr: 55.43
CAP%: 83.65%
HEALTH: 80.52%
GIDS: 226 (80.4%)

 

[surfingslovak]

Quotes from Shrink's link at Design News

Now they are telling us! Where were these experts hiding last year? It's good to see that the word is getting out though.

I think every charge and discharge event results in permanent changes to the structure of the battery. That's a given. The speed of charging is only one consideration in a whole chain of contributing factors, of which long-term effective battery temperature seems to be the most important one. The reason why I asked the rhetorical question above is simple: there are still too many diverging opinions. Some say that batteries shouldn't be fast charged at all or only rarely, others think that it could be OK, if the charge was limited to 80% and the battery was properly cooled. Although I'm leaning towards the latter, we can't be sure until we have proof. Real-world proof with real cars.

To add to the academic debate, here are the results of a study I found a while ago. It seems to indicate that a regular LMO consumer cell can be charged at 1C rate exclusively and only lose a few additional percentage points of capacity over its life compared to the best-case scenario, which happened to be 0.5C-rate charging. Slow charging was apparently not that good in the long run. In the discussion on the other thread, the consensus was that slow charging likely elevated the temperature of the cell, which was air cooled, for a significant amount of time. That said, a singular cell can be likely air cooled more effectively than a large pack.