Capacity Loss on 2011-2012 LEAFs

[RegGuheert]

There is a fan inside

For some reason I thought there was an internal fan to even out heat distribution. Guess I dreamt that up in my head.

No, you didn't dream it up. Nissan said there was a fan once-upon-a-time, but it never materialized in the production car.

Theoretically the "cooling" system is passive radiation from the pack to the outside air, obviously not effective in this case.

It's difficult to radiate heat to the air since air does not absorb infrared light effectively. Any radiation from the LEAF battery would be to other surfaces that surround it such as the floorboards or the plastic sheet below it, and, yes, that is pretty limited.

Most of the cooling of the LEAF battery when driving is through conduction to the unibody and conduction from both the battery and the unibody to the air. When the car is moving heat gets carried away by a form of convection due to the car moving to cooler air all the time. However, when the car is at rest, the warm air around the battery is somewhat trapped so the heat takes a long time to dissipate.

Since the LEAF battery is a net dissipater of heat, the lower temperature limit is the ambient air temperature. In reality, its average temperature will be above the ambient level. This is good when it is cold outside and bad when it is hot.

 

[lorax]

I did a bit of driving yesterday and took the car down to VLBW. To charge from VLWB to 100% was 16.9 KWh according to the Blink. It took about 4h 27m to charge. Assuming 85% charging efficiency, about 14.4 KWh were delivered to the battery.

Harsha

 

[lorax]

I also did a QC at PADT yesterday -- GOM was at 5 miles. Charged to 80%. According to the Blink website, 12.17 KWh delivered.

Harsha

 

[scottf200]

I did a bit of driving yesterday and took the car down to VLBW. To charge from VLWB to 100% was 16.9 KWh according to the Blink. It took about 4h 27m to charge. Assuming 85% charging efficiency, about 14.4 KWh were delivered to the battery. Harsha

How many miles were you able to drive :?:

 

[RegGuheert]

I did a bit of driving yesterday and took the car down to VLBW. To charge from VLWB to 100% was 16.9 KWh according to the Blink. It took about 4h 27m to charge. Assuming 85% charging efficiency, about 14.4 KWh were delivered to the battery.

Harsha

Assuming an extra 1.5 kWh of energy required From the wall had you gone to turtle, that indicates you can only put in 18.4 kWh/26.1 kWh = 70.5% as much energy as a new LEAF. That is consistent with having lost three bars (66.25% to 72.5% of original capacity).

I am basing this calculation on data from this thread: Collecting data:Off-the-wall power for turtle to 100% charge

Edit: Corrected my calculation to use consistent energy numbers (now all are from the wall).

 

[edatoakrun]

I did a bit of driving yesterday and took the car down to VLBW. To charge from VLWB to 100% was 16.9 KWh according to the Blink. It took about 4h 27m to charge. Assuming 85% charging efficiency, about 14.4 KWh were delivered to the battery.

Harsha

What kWh consumption did your LEAF report for the same trip, either calculated by using nav sceen m/kWh and odometer miles, or just using (if you can) the CW kWh use report?

 

[opossum]

After I got home around 64-65 miles, I started driving a loop around the neighborhood. Lights every mile or so, 35-40 mph. VLBW came on 74.3 miles. I pulled into my garage at 75.4 miles. Average was 4.3 miles/kWh. Ambient temps on the LEAF display were 88F on the way down, 92F on the way back. 6 temp bars the whole time. Mileage when I pulled in was 2220.

75.4 / 4.3 = 17.5 kWh. That's lower than I would have hoped/expected for a Phx Leaf with only 2220 miles on it! But I hate you a little for that sort of range. At this point, I don't think our Leaf could get 75 miles going downhill... on the back of a flatbed! :mrgreen:

 

[shrink]

75.4 / 4.3 = 17.5 kWh. That's lower than I would have hoped/expected for a Phx Leaf with only 2220 miles on it! But I hate you a little for that sort of range. At this point, I don't think our Leaf could get 75 miles going downhill... on the back of a flatbed! :mrgreen:

What? Clearly all you need to do is update that buggy software

 

[EatsShootsandLeafs]

Apologies for askign what must already have been asked, but this thread is gargantuan!

In this thread: http://www.mynissanleaf.com/viewtopic.php?f=30&t=9917" onclick="window.open(this.href);return false; Nissan mentions how there is no battery problem, but rather a faulty display. This certainly seems to me to be rubbish, but assuming it's not, how is it that if that is indeed the cause (buggy software) that 1) The software of the display hasn't been updated and 2) It disproportionately affects people in hot climates?

Why aren't people in New Jersey suffering from this "faulty" display?

 

[cwerdna]

In this thread: http://www.mynissanleaf.com/viewtopic.php?f=30&t=9917" onclick="window.open(this.href);return false; Nissan mentions how there is no battery problem, but rather a faulty display. This certainly seems to me to be rubbish, but assuming it's not, how is it that if that is indeed the cause (buggy software) that 1) The software of the display hasn't been updated and 2) It disproportionately affects people in hot climates?

Why aren't people in New Jersey suffering from this "faulty" display?

I agree the explanation seems like rubbish and we sure wish we got better communication from Nissan other than the "explanation" that someone stumbled across from Mr. Palmer. So far, neither of those has been explained, AFAIK.

It still seems like Phoenicians who had their Leafs taken to Casa Grande haven't heard back much that's of been of any use..

Hopefully Tony Williams' test in about a week goes as planned and w/o incident so we can further throw water on the claims there's no battery problem.

 

[DaveEV]

Some great information from GerryAZ regarding the broken gauges after losing a bar he's documented in the Collecting data:Off-the-wall power for turtle to 100% charge thread.

Incidentally, the car's instrumentation became erratic after losing the first capacity bar. SOC bars sometimes disappear quickly and other times are more like they used to be. The GOM (Nissan calls it the DTE meter) is all over the place--much worse than it was before losing the capacity bar. The first low battery warning (LBW) consistently comes sooner than it did before, but the range between LBW and the very low battery warning (VLBW) has increased significantly and the distance from VLBW to Turtle has also increased about the same amount as the increase between LBW and VLBW. The net effect is that the range is about the same as before the loss of the capacity bar, but much more of the mileage is after LBW.

Edited to add: I lost the second capacity bar at 13834 miles on 8/8/2012 (just before going on vacation), but I have not noted any additional changes to the instrumentation or loss of actual driving range.

 

[TonyWilliams]

Gerry's post is virtually devoid of hard data, or how he arrived at any of his observations. Can we please get his car at our test on Sept 15 (staging of cars on Sept 14) in Phoenix?

http://www.mynissanleaf.com/viewtopic.php?p=225481#p225481" onclick="window.open(this.href);return false;

Some great information from GerryAZ regarding the broken gauges after losing a bar he's documented in the Collecting data:Off-the-wall power for turtle to 100% charge thread.

Incidentally, the car's instrumentation became erratic after losing the first capacity bar. SOC bars sometimes disappear quickly and other times are more like they used to be. The GOM (Nissan calls it the DTE meter) is all over the place--much worse than it was before losing the capacity bar. The first low battery warning (LBW) consistently comes sooner than it did before, but the range between LBW and the very low battery warning (VLBW) has increased significantly and the distance from VLBW to Turtle has also increased about the same amount as the increase between LBW and VLBW. The net effect is that the range is about the same as before the loss of the capacity bar, but much more of the mileage is after LBW.

Edited to add: I lost the second capacity bar at 13834 miles on 8/8/2012 (just before going on vacation), but I have not noted any additional changes to the instrumentation or loss of actual driving range.

 

[lorax]

I did a bit of driving yesterday and took the car down to VLBW. To charge from VLWB to 100% was 16.9 KWh according to the Blink. It took about 4h 27m to charge. Assuming 85% charging efficiency, about 14.4 KWh were delivered to the battery.

Harsha

What kWh consumption did your LEAF report for the same trip, either calculated by using nav sceen m/kWh and odometer miles, or just using (if you can) the CW kWh use report?

Friday (started with 100% charge):
115.7 mi @ 4.5 mi/KWh (dash).
GOM was at 5 miles at QC charge. VLWB at L2 charge
QC+L2 Charge: 12.17 + 16.9 = 29.1 KWh.
Wall to wheels: 115.7/29.1 = 3.98 mi/KWh
Charging efficiency: 3.98/4.5 = 88.4%.

Saturday (started with 100% charge):
46.8 mi @ 4.5 mi/KWh (Dash)
GOM: 17 mi with 2 bars left.
L2: 12.8 KWh overnight
Wall to wheels 3.65 mi/KWh.
Charging efficiency: 3.65/4.5 = 81.2%
Average speed 36.5 MPH (dash)

(On weekends, I tend to charge to 100%. On weekdays, I charge to 80%).

I am looking at battery performance from a slightly different angle than TonyWilliams. Tony is charging to 100% and then driving until the battery hits turtle. I am driving and then measuring how much energy it takes to recharge the battery. The two approaches should be similar.

Also, the odometer is at 26,331 mi.

Harsha

 

[TonyWilliams]

I am looking at battery performance from a slightly different angle than TonyWilliams. Tony is charging to 100% and then driving until the battery hits turtle. I am driving and then measuring how much energy it takes to recharge the battery. The two approaches should be similar.

Also, the odometer is at 26,331 mi.

Harsha

Unfortunately, there are plenty of variables to consider in determining how much energy to fill up the depleted battery and comparing that data to other reports. Voltage and amperage is a huge factor on efficiency. Temperature of the battery. SOC of the battery. Degradation (hence internal resistance). Accuracy of the meter measuring the power.

Nobody, yet, (except Nissan) even has a method to measure battery temperature.

 

[opossum]

It still seems like Phoenicians who had their Leafs taken to Casa Grande haven't heard back much that's of been of any use..

Exactly right. Our car went to the dealership Friday for a battery test to 'document' the loss of a 3rd capacity bar. When I talked to our service advisor that day, he had indicated that a 'task force' was in the process of being assembled. I made it clear to the advisor that we were growing extremely frustrated both with Nissan's denial of an issue and with their complete lack of feedback on the Casa Grande testing or any other testing or investigations. I told the advisor earlier in the week that we wanted something in writing explaining what had been done in Casa Grande, but he said the task force was not yet prepared to share anything. Our Leaf has been to Casa Grande and dealerships about 10 times now since capacity loss was noticed. I'll share with everyone ALL of the information Nissan has shared with us in the last 4 months:

86% capacity remaining when measured in Casa Grande (spoken, not in writing)
(The End)

:evil: :roll:

 

[mdh]

It still seems like Phoenicians who had their Leafs taken to Casa Grande haven't heard back much that's of been of any use..

Exactly right. Our car went to the dealership Friday for a battery test to 'document' the loss of a 3rd capacity bar. When I talked to our service advisor that day, he had indicated that a 'task force' was in the process of being assembled. I made it clear to the advisor that we were growing extremely frustrated both with Nissan's denial of an issue and with their complete lack of feedback on the Casa Grande testing or any other testing or investigations. I told the advisor earlier in the week that we wanted something in writing explaining what had been done in Casa Grande, but he said the task force was not yet prepared to share anything. Our Leaf has been to Casa Grande and dealerships about 10 times now since capacity loss was noticed. I'll share with everyone ALL of the information Nissan has shared with us in the last 4 months:

86% capacity remaining when measured in Casa Grande (spoken, not in writing)
(The End)

:evil: :roll:

I think this is a very positive sign... "task force." And, the dealer is not pushing back.

 

[opossum]

I think this is a very positive sign... "task force." And, the dealer is not pushing back.

What aggravates me is all the time "lost." Even if you ignore the fact that we've been complaining about capacity loss since late April and early June, our cars returned from Casa Grande on August 6th. So they *finished* with their Nissan corporate pud-holding convention down at the test track over a month ago... and *now* they're getting around to forming a task force? Sorry, but that's dragging of the feet, even for a huge corporation. I work for an engineering company with over 125,000 employees worldwide, and yet we would still mobilize faster than this for an issue of this magnitude. Our car is dangerously close to reaching the point at which my wife can't even make a trip to work and back (she already has to skip trips to the gym after work now). Seeing Nissan give us the silent treatment and attack this with the speed of a sloth does not make me happy. Nissan Arbitration hasn't even returned our calls for several weeks now...

 

[theaveng]

What aggravates me is all the time "lost." ..... Sorry, but that's dragging of the feet, even for a huge corporation.

For the corporation's viewpoint this is not a big deal. When your car is no longer functional it will just buy the car back and throw it into a crusher like GM did with the EV1s. To you it is an emergency but to it, the car is not a problem. The problem can be made to go away by throwing a bit of money at the customer.

My wife almost can't make ONE trip to work in the car now. Roughly 10 trips to dealers and a test facility. Countless work hours and weekends lost.

Lost work hours = money lost. I'd be putting the Leaf in the garage and getting another car. I saw a really nice 50,000 mile Civic Hybrid for $6600 on ebay. Used Priuses and Insights have slightly higher pricing. All 3 get around ~45mpg on highway driving and are rated SULEV in California and the Northeast states. (Don't know what they are in your home.)

 

[mdh]

I think this is a very positive sign... "task force." And, the dealer is not pushing back.

What aggravates me is all the time "lost." Even if you ignore the fact that we've been complaining about capacity loss since late April and early June, our cars returned from Casa Grande on August 6th. So they *finished* with their Nissan corporate pud-holding convention down at the test track over a month ago... and *now* they're getting around to forming a task force? Sorry, but that's dragging of the feet, even for a huge corporation. I work for an engineering company with over 125,000 employees worldwide, and yet we would still mobilize faster than this for an issue of this magnitude. Our car is dangerously close to reaching the point at which my wife can't even make a trip to work and back (she already has to skip trips to the gym after work now). Seeing Nissan give us the silent treatment and attack this with the speed of a sloth does not make me happy. Nissan Arbitration hasn't even returned our calls for several weeks now...

I agree with you... not fast enough. At least a wheel is turning... I am just glad there is a heart beat as the silence is amazing.

 

[theaveng]

20% at 5 years is gradual, 5% a month, is not. No traction battery that is at end of life at 2 years has gradual loss.

5% per month is gradual. Lots of batteries have the level of loss. Like alkaline.

http://www.youtube.com/watch?v=DShtvd5jJHQ http://www.nissan-global.com/EN/REPORTS/2011/08/110803.html" onclick="window.open(this.href);return false;
Interesting that Mark Perry says the frequently repeated 70-80% battery capacity in 10 years, "and that is gradual".

Good catch.