Capacity Loss on 2011-2012 LEAFs

[edatoakrun]

...Those two statements appear to be in direct conflict unless I assume the first one is from 100% to LBW while the second is from 100% to turtle (or disconnect). Is that what you meant?

See edits for clarity.

"RegGuheert"
...Ed's long-distance drives at very slow speeds tell us that much of the capacity is still there, but is is not available to those driving on the highway...

I can recall multiple posts reporting on ranges far longer than LBC-projected at higher speeds, as well.

I suggest (those who can) actually test that fraction of the available capacity, matching all the conditions of any one of the 70 mph AVTA LEAF tests as closely as possible.

The higher the speed, the less any efficiency changes your LEAF or its tires have experienced should have on the results.

At the lower speeds I drive, the range loss is considerably less than my pack's available capacity loss, evidently due to lower rolling resistance (tread wear-adjusted) of my replacement ecopias, and/or a reduction in drivetrain friction from when I began range-testing, at ~3k miles from new.

BTW, in addition to your suggestion that the LBC may allow a lower % of access to the total capacity when driving at higher speeds, it is also entirely possible (IMO) that actual cycling efficiency (or, perhaps just discharge efficiency at high rates/high speeds) decreases as the battery ages.

There is an old discussion on the Volt thread RE the apparent decrease in discharge efficiency from AVTA data.

 

[TimLee]

... Does anyone know the exact voltage of the lowest cell when the battery disconnects? ...

Information I posted back on June 2, 2015:

I let my two capacity bar loss 2011 LEAF go to contact opening yesterday and determined that it was NOT triggered by lowest cell voltage being 3.0 volts.

Turtle happened at 0.4 kWh remaining.
At turtle drive power is limited to 20 kW and HVAC is eliminated.
Blower will run off the 12V, but AC or heat will not operate.
At turtle lowest cell voltage was around 3.2 volts with cell low to high up around 240 mV.

As I watched lowest cell voltage was down to around 3.109.
But LEAF was still doing cell balancing.
The lowest cell voltage turned and improved.
It climbed back to near 3.2 volts with cell low to high improved to 192 mV.

And then the Turtle indication disappeared when it opened the contactor.
Remaining was still 0.3 kWh at that point.
Unclear to me what value it used to determine it was necessary to open the contactor.

Vehicle was parked in garage.
But it would not have driven very far with only 0.1 kWh.
I was lucky I made it into the garage when it Turtled on the hill previously 500 feet from the garage :shock:

 

[RegGuheert]

... Does anyone know the exact voltage of the lowest cell when the battery disconnects? ...

Information I posted back on June 2, 2015:

Thanks, Tim! Very interesting. It seems all we can say is that when the lowest cell is *around* 3.0 V, you are in danger of seeing the turtle followed shortly by the contactor opening.

 

[TimLee]

I observed high voltage disconnect a couple times in the past few weeks and got similar results.
Cell voktages at High Voltage Disconnect:
3.108 Min, 3.199 Ag, 3.275 Max (162 mV delta)
3.108 Min, 3.193 Ag, 3.275 Max (167 mV delta)

Clearly some people with much newer batteries have seen lower values around 2.8 or possibly 2.7.

But from my observations the disconnect occurs when the LEAF reports remaining capacity of 0.3 kWh.

That usually happens any where from 15 seconds to one minute after LEAF Spy Pro SOC hits 0.0%.

Once disconnect happens usually remaining will drop to 0.2 kWh very quickly.

But the pack is still working on balancing and remaining will slowly improve to 0.4 kWh with some increase of the lowest cell pair voltage.

NOTE:
Once high voltage disconnect happens the 12V battery is now on its own.
With the LEAF still on and the OBDII Bluetooth adapter powered it will be discharging at a high rate around 8 amps, or much higher if AC was on and blower at higher speed.
Very bad for the 12V battery.
As long as you don't turn it off 12V will stay active (apparently due to safety concerns, hazard flashers may be important depending on where it disconnected the high voltage pack).
Once the 12V voltage sags to around 9 volts you will have to jump the LEAF off using another vehicle or battery.

Once high voltage disconnect has happened and LEAF has been turned Off, it will not start again until you have charged up to around 40 GID or 2.0 kWh remaining IIRC.
AC will not go back to working till up around 60 GID.

 

[TimLee]

... It seems all we can say is that when the lowest cell is *around* 3.0 V, you are in danger of seeing the turtle followed shortly by the contactor opening.

No, what I have observed is that Turtle always happens when LEAF Spy Pro shows 0.4 kWh remaining and the High Voltage Disconnect always happens when it shows 0.3 kWh remaining.

The LEAF calculation of kWh remaining may partially be a function of lowest cell pair voltage, but it is more than just voltage.
Older LEAF with lower Hx it will be a higher lowest cell pair voltage when Turtle happens than with a brand new high voltage pack.

 

[o00scorpion00o]

Here is a 2011 Irish leaf (U.K imported) with almost 80% capacity after 38,000 miles, This can't be normal can it ? I met this man at a DC point a few weeks ago.

Could the odometer have been turned back and would leafspy still report the correct mileage ?

 

[RegGuheert]

Here is a 2011 Irish leaf (U.K imported) with almost 80% capacity after 38,000 miles, This can't be normal can it ? I met this man at a DC point a few weeks ago.

I think it can be normal. UK has a cool climate so that amount of degradation seems reasonable after four years and 38,000 miles. Has it lost any capacity bars, yet?

Could the odometer have been turned back and would leafspy still report the correct mileage ?

Turned back? Are you thinking this car really should show LESS degradation than 17%?

 

[mwalsh]

I think it can be normal. UK has a cool climate so that amount of degradation seems reasonable after four years and 38,000 miles.

Just a small point of order - much of Ireland is not a part of the UK.

Éirinn go Brách!

 

[RegGuheert]

I think it can be normal. UK has a cool climate so that amount of degradation seems reasonable after four years and 38,000 miles.

Just a small point of order - much of Ireland is not a part of the UK.

Éirinn go Brách!

My understanding of his post is that this LEAF was imported (to Ireland) from the UK. As such, I had assumed it was used. (All 2011 LEAFs and their batteries were manufactured in Japan, so it was NOT manufactured in the UK.)

 

[RonDawg]

I think it can be normal. UK has a cool climate so that amount of degradation seems reasonable after four years and 38,000 miles.

Just a small point of order - much of Ireland is not a part of the UK.

Éirinn go Brách!

My understanding of his post is that this LEAF was imported (to Ireland) from the UK. As such, I had assumed it was used. (All 2011 LEAFs and their batteries were manufactured in Japan, so it was NOT manufactured in the UK.)

We don't know when it was imported, so technically you could be right and the car could have spent most of its life in the United Kingdom before being brought to the Republic of Ireland.

You are correct in that the weather of the British Isles helps preserve the battery.

 

[o00scorpion00o]

I think this car came from the U.K mainland.

Anyway, I was thinking DC charger abuse but hardly at this amount of dc charges.

Yes there is one capacity bar lost.

I wasn't expectation almost 20 % loss after 4 years and pretty low mileage ?

The 2014+ battery seems to be much more robust, a early 2014 I tested in February had still 100% and 67.7 AH after 18,000 miles and the U.K taxi with 102,000 and 83% capacity and 5,500 odd DC charges. I Think it was a 2013.

I wouldn't have expected calender loss to be so high.

 

[keydiver]

What mileage was his dash odometer reading? I'm not sure how LeafSpy handles the difference between km and miles. Are you saying there is a diference between the two?
Without knowing exactly where that Leaf came from, its very hard to say if the degradation is normal or not. I'm at 39,000 miles, and about to lose my 4th bar, so everything is relative, especially relative to where you live. If the Leaf was in the UK, maybe they lived inland southern UK, and left it charged at 100% on the hot asphalt parking lot all day. Who knows?

 

[o00scorpion00o]

The mileage was much the same, didn't check exactly.

There is one Leaf in Ireland that I know of that had around 70,000 before the loss of the fist bar a bit like Steve Marsh, did he loose his first bar around 70,000 miles also ? Isn't he in Seattle ? so probably a climate not do distant from ours .

This is why I'm thinking something isn't right.

 

[RegGuheert]

The mileage was much the same, didn't check exactly.

There is one Leaf in Ireland that I know of that had around 70,000 before the loss of the fist bar a bit like Steve Marsh, did he loose his first bar around 70,000 miles also ? Isn't he in Seattle ? so probably a climate not do distant from ours .

This is why I'm thinking something isn't right.

Calendar degradation is a bigger factor in the 2011 LEAF than the effects of cycling. As a result you will get the MOST miles from a LEAF by driving it a lot and the least by driving it very little.

The results you are seeing are very believable.

 

[Valdemar]

As a result you will get the MOST miles from a LEAF by driving it a lot and the least by driving it very little.

Depends on where you live. In SoCal to get the MOST miles from a LEAF you drive not more than 12,000 miles annually for the first 5 years, get your pack replaced under warranty, and then drive it a lot

 

[GetOffYourGas]

I think this is the right place to report this. I've officially lost my first bar. I noticed it today after work. I am not surprised to see it go, but was surprised by the timing - it has been getting chilly lately. I cannot seem to get LeafSpy to connect on my android tablet and my phone is an iPhone so unfortunately I don't have much more information than what's captured in the picture. I took delivery of the car on 3/9/12. It was manufactured 1/12 according to the door jam.

Edit: I guess I still don't know how to embed a picture in a post here. Here's a link to the picture:
https://www.dropbox.com/s/15lab4g92jrt5zi/First Bar Loss.JPG?dl=0

 

[Rat]

I finally lost my first bar. I have a 2011 that I got in June 2011. Being retired, I don't commute or drive that much. I noticed it two or three days ago at odometer reading of 20,385 miles. It's normally charged at night on my home Blink EVSE to 80%. I have only charged it on Level 3 chargers perhaps 5 or 6 times. I do occasionally charge to 100% at home. Climate here in the SF Bay Area is very mild and the car is garaged when not in use. I don't suppose there's anything remarkable here, but here's one more data point for those keeping score.

 

[ampitupco]

They day has come - I've lost my first bar. A 2012 LEAF Delivered in Jan 2012 with 33,000 miles currently. I was really hoping (and thinking) it would get to next summer before losing a bar. This fall has been brutal in Denver -- almost 90 degrees yesterday in October. The cool weather did not come soon enough to stop the capacity loss.

 

[vrwl]

Lost my 2nd bar today. 19,630 miles. Entry added to the MyNissanLeaf.com Wiki at http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss#Loss_of_two_battery_capacity_bars_.2821.25.25.29 along with comments detailing the car's split time between Dallas, TX and the Poconos of PA.

Stats from Leaf Spy Pro at 100% charge: 211 GIDS, 16.4kWh, 51.51 AHr, Hx 60.23%, SOH 78%. 7 lifetime QC's, 1253 Lifetime L1/L2 charges.

 

[dhanson865]

Lost my 2nd bar today. 19,630 miles. Entry added to the MyNissanLeaf.com Wiki at http://www.electricvehiclewiki.com/Real_World_Battery_Capacity_Loss#Loss_of_two_battery_capacity_bars_.2821.25.25.29 along with comments detailing the car's split time between Dallas, TX and the Poconos of PA.

Stats from Leaf Spy Pro at 100% charge: 211 GIDS, 16.4kWh, 51.51 AHr, Hx 60.23%, SOH 78%. 7 lifetime QC's, 1253 Lifetime L1/L2 charges.

I'm near that with 51.85 aHr and 61.03 Hx and 79% SOH. I just don't know if it will be this fall or next spring when the bar drops.

My car was in North Carolina to start and moved to Tennessee when I became the 2nd owner.

Just to show you how mileage doesn't matter as much as heat you have half the miles as me. I'm at 42,455 and counting.

Car was made in 10/11 so I'm 48 months in and 42,455 miles so I'm not sure if I'll hit 60 months or 60,000 miles first.

Either way I'm thinking I'll hit the limit before the 3rd bar drops so no free battery for me.

Sounds like you'll hit the months before you lose the 4th bar unless you take it back south again.