Capacity Loss on 2011-2012 LEAFs

[Herm]

I would be curious in how long of drives they did on their testing on a daily basis..I need 80 miles..
The dealer went over everything with me that lasted close to 2 hours..I told the salesman this car was going to be the workhorse with 80 mile avg. drives ,his reply was this car was the right choice and I should have years of problem free driving..

I wont say anything about believing what a car salesman will tell you because there must be a few in the world that are honest.

The battery in the Leaf is good for 1000 cycles, at your usage rate of 80 miles every day times 335 times a year that works out to a life of 3 years.. probably less under Phoenix conditions. True there are examples with very mild usage that have lost capacity. Nissan knows all this because they get a detailed battery report from every owner yearly.. I hope they file the reports for further study.

Lithium-ion batteries have a limited number of cycles they can handle.. the owner that gets 73 miles from a cycle will not have the same outcome as the owner that gets 150 miles from each cycle. The Leaf should have never been marketed as a long distance commuter.

 

[Herm]

Looking at the EV Project data, it's scary how many people are charging between 9pm-12am (leaving 8 hours storage at "full") and how many are charging to 100% (~65% Phoenix EV Project participants and ~50% Tuscon EV Project participants).

At the same time - the difference between 80%/100% charging habits don't seem to have a significant effect on real-life LEAFs in hot-weather climates like AZ which is a bit of a mystery as in theory, storage at 80% should cut degradation rate in half compared to 100% (perhaps less in the LEAF since 100% is really only ~94% but it should still be easily seen).

Edit: Found the source of the image - comes from a NREL study: http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/53817.pdf" onclick="window.open(this.href);return false;

That is a scary study, even the OP of this thread admitted they always charged to 100%, that along with the extreme temperatures found in Phoenix is a lethal combination.

Thanks for the link.

 

[mwalsh]

I am tempted to push my 80% end-timer out from stopping around ~5am closer to my usual 8-9am departure time even though that would increase my cost to charge about 20%. Doing so would get me 3-4 hours/day less time spent at 80% SOC instead spent at 30-50%.

That's what I did. Charging gets done at 6:30am now instead of at 4:30am, 2 hours closer to my 9am departure. I could set it to finish even closer, but I'd rather the car be ready to go in case I got called in to work early on an emergency.

 

[Herm]

This is just devastating news for Leaf owners in Phoenix:

 

[JPWhite]

I, for one, would not have become an early adopter if Nissan has disclosed all this stuff about waiting for the battery to cool down before charging, or that 80% charge stored all night long is bad, etc. There's a balance before too many charging requirements becomes a nuisance and not worth using. After all, people buy the car to serve them, not the other way around.

I wondered about this shortly after purchasing and contacted the customer service folks, by chat of course to get a written record. here's what they said.

Please wait while we find an agent to assist you...

You have been connected to Eric W.

Eric W: Thank you for contacting Nissan LEAF Consumer Affairs. How may I assist you?

JP White: Hi I've been reading the Owners Manual and have a question regarding some advice it gives......

Eric W: Go ahead.

JP White: ..... On page EV-22 it says to let the batery cool after use prior to charging. Does that apply even if the battery temp is in the normal range?

Eric W: The intention is not to attempt to charge the battery if the temperature of the battery is above a certain point at which charging could be detrimental to the battery.

JP White: Normally it maintains 'six bars' on the temperature gauge. Is that an acceptable temp to begin charging or should one wait anyway?

Eric W: Just a moment please.

JP White: k

Eric W: It should be acceptable to charge the vehicle if the battery temperature gauge shows that the battery is within normal range (between the blue and red gauge squares.

JP White: OK Thanks. That answers my question

Eric W: Is there anything else I can assist you with today?

JP White: No Thanks. I appreciate your help today.

Eric W: Thank you for contacting Nissan LEAF and have a good day.

The User manual contradicts itself, of course, here's what the user manual says.

EV-20

NISSAN recommends that you connect
the normal charge cable when getting
out of the vehicle, even if it is not going
to be used. By doing this, you can get
the most out of the remote climate
control and Climate Ctrl. Timer functions
the next time you use the vehicle

EV-22

Allow the vehicle and Li-ion battery to cool
down after use before charging.

The only way to connect the charging cable without initiating a charge is to have an end-timer set. Nissan don't explain that very well. Drivers can be excused for not knowing this stuff. Personally I charge to 80% all the time and will charge immediately after stopping if I anticipate using the vehicle again that day.

The advice to let the battery cool down after use before charging kinda makes EVSE's at restaurants useless. By the time it has cooled down it'll be time to leave. Clearly one will charge immediately after stopping the vehicle or just not bother to park in the space if a charge isn't necessary. Last night had I NOT charged my vehicle at the restaurant we ate at, I wouldn't have got home. Waiting for the battery cool after driving makes use of L3 quick chargers very inconvenient. Wait 30 minutes than charge for 20? If that's true, the car is too fragile for everyday use by everyday folks.

I'm not convinced the difference between 80% and 100% is as big a factor to premature battery degradation as is ambient temperature. I noticed a loss of range shortly after the most recent heat wave when we broke all records for June temperatures. The only advice Nissan give about ambient temperature is keep it below 120, which clearly doesn't work for those in AZ.

 

[KJD]

While there is probably a temperature at which degradation really takes off, in general the colder the battery, the longer it will last

Yes I would agree with this and this is often overlooked.

Nissan clearly hasn't educated customers well enough on the potential benefits of using and end-only-timer.

To me this is the biggest mistake made by Nissan so far. It is a great feature of the car and more people should be using it.

 

[KJD]

Looking at the EV Project data, it's scary how many people are charging between 9pm-12am (leaving 8 hours storage at "full")

I don't blame people for wanting to plug in right away after they get home and charge to 80% between 9pm-12am. They want their car to be ready at full 80% capacity as soon as possible to serve them whenever needed. After all, Nissan never said anything about doing that being bad for the battery. All Nissan recommends is 80% charge and you can't blame people for doing things Nissan never said is bad for the battery.

The Nissan documentation sucks. Get over it.

I, for one, would not have become an early adopter if Nissan has disclosed all this stuff about waiting for the battery to cool down before charging, or that 80% charge stored all night long is bad, etc. There's a balance before too many charging requirements becomes a nuisance and not worth using. After all, people buy the car to serve them, not the other way around.

I guess we could all go back to driving monster sized SUV's and sending a billion dollars a day to OPEC. I would rather see if we can make this car work.

But since Nissan chose to not disclose or require people to do any of these practices, it's on Nissan's head to be held responsible if these practices that Nissan condones (by not saying anything about them) becomes detrimental to battery life.

I seriously doubt Nissan withheld any information on purpose. It appears their testing for AZ was flawed. Lets see if they can find the problem and fix it. This will not be fixed overnight, it will take some time.

 

[pchilds]

First 100% charge with my new LeafCan meter, 89% GID 250, not a big surprise. Will my Leaf be the second California Leaf to lose a bar?

I have had my Leaf for just under one year and 8700 miles, the car splits its time between San Diego and Temecula, charge to 80%, 90% of the time.

Last summer was very mild for Temecula, capacity loss could have been much worse.

Edited to correct mileage.

 

[DaveinOlyWA]

This is just devastating news for Leaf owners in Phoenix:

we need waaaay more information about this chart. originally i was happy to see it, but now i realize it is causing more grief than it is worth.

i do not think the temperatures on this graph can be correlated to the LEAF pack. it is simply too low. also keep in mind, this is constant temps and not the occasional spikes we really need to be concerned about here. the chart does not go high enough and if it did, no one maintains temps at 40C.

if we are talking ambient pack temperatures, i am at that risk right now every time i QC or anytime i am out driving in Summer. OAT of 75º in bright sunlight can mean an ambient temp well into the 90º for hours on end. am i at risk as well? i tend to park in the shade if its available because i dont want a hot car but more a lot of my options shade is NA. my previous work where i parked till 5:30 PM daily has ZERO shade of any kind (other than light poles...)

a few days ago while parked in my garage, i had a temp probe sitting under the car. the garage door was open but there was minimal Sun shining in (only went about 3 feet past door opening) and the probe was still at 32C and OAT was only 79F. was i at risk?

no, i dont think so. if this chart was accurate, i would be seeing something by now and i am not.

 

[KJD]

First 100% charge with my new LeafCan meter, 89% GID 250, not a big surprise. Will my Leaf be the second California Leaf to lose a bar?
I have had my Leaf for just under one year and 9500 miles, the car splits its time between San Diego and Temecula, charge to 80%, 90% of the time.
Last summer was very mild for Temecula, capacity loss could have been much worse.

I have only had my GID meter for a couple of weeks and the readings have been pretty consistent.

The only time I noticed a decrease in GID count was the day after I did a top off charge in the late afternoon. The temp difference between high and low of the day is often 20 to 30 degrees here. Maybe that difference is enough to cause problems.

My question for people who have had a GID meter for a long time, have you noticed the GID number going down the day after charging during the heat of the day. Do your GID numbers stay more consistant when using the end-only-timer to charge during the coolest hours of the day?

 

[sparky]

I am tempted to push my 80% end-timer out from stopping around ~5am closer to my usual 8-9am departure time even though that would increase my cost to charge about 20%. Doing so would get me 3-4 hours/day less time spent at 80% SOC instead spent at 30-50%.

That's what I did. Charging gets done at 6:30am now instead of at 4:30am, 2 hours closer to my 9am departure. I could set it to finish even closer, but I'd rather the car be ready to go in case I got called in to work early on an emergency.

I would happily use the end-timer for daily charging, but I've been waiting 18 mos for Blink to fix my EVSE. It ground-faults every few days at the onset of the charge cycle so, I can see/hear the error and reset the Blink if I it's set to start charging right away. I can't afford to play roulette with the next day's driving option. So that's one of the data points for the EV Project's many "charge as soon as they get home" stats.

 

[DaveinOlyWA]

I am tempted to push my 80% end-timer out from stopping around ~5am closer to my usual 8-9am departure time even though that would increase my cost to charge about 20%. Doing so would get me 3-4 hours/day less time spent at 80% SOC instead spent at 30-50%.

That's what I did. Charging gets done at 6:30am now instead of at 4:30am, 2 hours closer to my 9am departure. I could set it to finish even closer, but I'd rather the car be ready to go in case I got called in to work early on an emergency.

I would happily use the end-timer for daily charging, but I've been waiting 18 mos for Blink to fix my EVSE. It ground-faults every few days at the onset of the charge cycle so, I can see/hear the error and reset the Blink if I it's set to start charging right away. I can't afford to play roulette with the next day's driving option. So that's one of the data points for the EV Project's many "charge as soon as they get home" stats.

problem with plugging it in just before you go to bed? if so, have your children do it. that is what i do. unlike me, my 5 year old son

very much enjoys doing it for whatever strange child reason he has in his head.

 

[KJD]

I would happily use the end-timer for daily charging, but I've been waiting 18 mos for Blink to fix my EVSE. It ground-faults every few days at the onset of the charge cycle so, I can see/hear the error and reset the Blink if I it's set to start charging right away. I can't afford to play roulette with the next day's driving option. So that's one of the data points for the EV Project's many "charge as soon as they get home" stats.

And 18 months from now you will still be waiting.
If you end up destroying your battery pack early because of using a "Free" blink charger are you really saving any money ?

The EVSE upgrade is a good low cost alternative and it works every time no problem.

 

[ericsf]

I would happily use the end-timer for daily charging, but I've been waiting 18 mos for Blink to fix my EVSE. It ground-faults every few days at the onset of the charge cycle so, I can see/hear the error and reset the Blink if I it's set to start charging right away. I can't afford to play roulette with the next day's driving option. So that's one of the data points for the EV Project's many "charge as soon as they get home" stats.

And 18 months from now you will still be waiting.
If you end up destroying your battery pack early because of using a "Free" blink charger are you really saving any money ?

The EVSE upgrade is a good low cost alternative and it works every time no problem.

+1
Not having to worry about charging at home is worth every penny. I tough I was a sucker for having paid for my AV charging station but now I can't imaging having to deal with a dead battery when it's time to go to work. I changed my charging timer from start time to end time about 6 months ago (when I learned about this feature on this forum) to minimize the time spent at high SOC. It has worked flawlessly and I think the "end of charge" should be the recommended way to use the timer.

Last time I had to deal with a dead battery was when my 8yo VW Golf refused to start when I had to move it to the other side of the street because of street cleaning (which now accounts for 80% of the miles we drive it for). It was quite enjoyable to drive to O'Reilly with my LEAF to buy a battery

 

[thankyouOB]

cute kid, dave.
blessings.

 

[LEAFfan]

First 100% charge with my new LeafCan meter, 89% GID 250, not a big surprise. Will my Leaf be the second California Leaf to lose a bar?

You have about 9% more to lose before you lose your first bar.

 

[DaveinOlyWA]

cute kid, dave.
blessings.

thank you!

 

[DaveEV]

Looking at the EV Project data, it's scary how many people are charging between 9pm-12am (leaving 8 hours storage at "full")

I don't blame people for wanting to plug in right away after they get home and charge to 80% between 9pm-12am. They want their car to be ready at full 80% capacity as soon as possible to serve them whenever needed.

I can see the psychology behind this - but at least personally in over a year of LEAF ownership - there has been zero cases where I've needed to go out again after getting home. And even if I did (and I suspect the vast majority of other LEAF owners as well), I have another car should I need the range.

I do think that a multi-stage charge setting could be beneficial - something where you can program something like this:

1. Charge at least to 30% regardless of time (to maintain some reserve for emergencies).
2. Charge to 70% during super-off-peak hours (to minimize charging cost).
3. Top off battery by set time (to minimize time spent at high SOC).

Probably too complex for the typical owner (would also need to offer an "easy" mode), but I can guarantee you that people would use that feature if available once educated on the benefits.

After all, Nissan never said anything about doing that being bad for the battery. All Nissan recommends is 80% charge and you can't blame people for doing things Nissan never said is bad for the battery.

Nissan specifically stated that one shouldn't charge again until SOC is below 80% and that one should let the pack cool before charging. It is too bad that they didn't also say that delaying charge until closer to expected departure time can also be very beneficial. But still - what about the 50%+ EV project owners in AZ charging to 100%?

I, for one, would not have become an early adopter if Nissan has disclosed all this stuff about waiting for the battery to cool down before charging, or that 80% charge stored all night long is bad, etc. There's a balance before too many charging requirements becomes a nuisance and not worth using. After all, people buy the car to serve them, not the other way around.

This was all disclosed before one received their car. But perhaps not quite as prominent as it should have been.

I seriously doubt Nissan withheld any information on purpose. It appears their testing for AZ was flawed. Lets see if they can find the problem and fix it. This will not be fixed overnight, it will take some time.

Something definitely going on... I really can't imagine that Nissan would sell a car where the typical car is expected to lose 20-30% capacity in 2-3 years instead of the 5-10 years that they have claimed.

we need waaaay more information about this chart. originally i was happy to see it, but now i realize it is causing more grief than it is worth.

i do not think the temperatures on this graph can be correlated to the LEAF pack.

It can be correlated, (all lithium chemistries are affected similarly to temperature, just in different degrees) but it should only be used as a relative measure of how temperature and SOC can accelerate degradation.

First 100% charge with my new LeafCan meter, 89% GID 250, not a big surprise. Will my Leaf be the second California Leaf to lose a bar?

You have about 9% more to lose before you lose your first bar.

Yep, still quite a ways before you lose a bar. I suspect that after 1 year in southern california, GID readings of 250-260 is fairly typical. I really need to get a GID meter, but my seat-of-the-pants estimate based on other data puts it in that ballpark.

 

[Stoaty]

The other interesting tidbit to pull from this study is that the lower SOC is extremely beneficial to battery life. Storing the NCA battery at 40% SOC / 35C results in the same degradation rate as storage at 80% SOC / 17C. Also, using "just-in-time" charging to 100% results in basically the same degradation rate as just-in-time charging to 80%. Nissan clearly hasn't educated customers well enough on the potential benefits of using and end-only-timer.

I am tempted to push my 80% end-timer out from stopping around ~5am closer to my usual 8-9am departure time even though that would increase my cost to charge about 20%. Doing so would get me 3-4 hours/day less time spent at 80% SOC instead spent at 30-50%. Storage at 40% SOC is about half as bad as storage at 80% SOC which is about half as bad as storage at 100% SOC.

Edit: Found the source of the image - comes from a NREL study: http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/53817.pdf" onclick="window.open(this.href);return false;

Interesting info, but remember that NCA means "Lithium Nickel Cobalt Aluminum Oxide" cathode, while the Leaf has LMO cathode which is "Lithium Manganese Oxide". Each battery chemistry has different characteristics, so what applies to one may not apply to another. See:

http://batteryuniversity.com/learn/article/types_of_lithium_ion" onclick="window.open(this.href);return false;

for general characteristics of different cathode types.

 

[thankyouOB]

drees,
how do you estimate gids without a meter?
and did folks get the meters from gary.

i need one, but would rather wait for ingineer's new gizmo, with the cool display and easy hook up.