Capacity Loss on 2011-2012 LEAFs

[cwerdna]

^^^
Excellent! Great material to add to http://archive.org/web/web.php" onclick="window.open(this.href);return false;.

As I've asked at http://www.mynissanleaf.com/viewtopic.php?f=12&t=9553" onclick="window.open(this.href);return false;, if you come across something interesting that would be useful if archived for future reference, add to to archive.org! Better than getting a 404 at some point in the future...

 

[TickTock]

Wanted to share this here. Explains why there is a temperature dependance to the battery available charge guage and gid count. Reasonable to assume the capacity guage, too, is influenced by this temperature effect. This supports the notion that some of the degradation seen via gid count or bars lost will be recovered during cooler months although I will be surprised if the actual capacity as measured from the wall improves this winter.

 

[Herm]

Uhh... I wouldn't just call David Champion a "PR guy", per the Businessweek article I cited at http://www.mynissanleaf.com/viewtopic.php?f=12&t=9793" onclick="window.open(this.href);return false;, he was "senior director of Consumer Reports Auto Test Center".

Sorry, I meant to say the new job at Nissan Casa Blanca is a PR management job, per an article I read. He will be the guy that comes out to the parking lot to talk to the picketing Leaf owners.

 

[RegGuheert]

Reasonable to assume the capacity guage, too, is influenced by this temperature effect.

Agreed that is a reasonable assumption. But, as I have pointed out before, Nissan makes the claim on the page you posted, as well as on others, that "Li-ion battery capacity level gauge is immune to temperature change."

 

[TickTock]

Reasonable to assume the capacity guage, too, is influenced by this temperature effect.

Agreed that is a reasonable assumption. But, as I have pointed out before, Nissan makes the claim on the page you posted, as well as on others, that "Li-ion battery capacity level gauge is immune to temperature change."

Good point - I was assuming they meant short-term temperature change (i.e. change during one charge-discharge cycle) since that is what the page deals with, but you can certainly interpret that to include long-term effects, too.

 

[edatoakrun]

Wanted to share this here. Explains why there is a temperature dependance to the battery available charge guage and gid count. Reasonable to assume the capacity guage, too, is influenced by this temperature effect. This supports the notion that some of the degradation seen via gid count or bars lost will be recovered during cooler months although I will be surprised if the actual capacity as measured from the wall improves this winter.

I'd be surprised if you don't see the actual capacity as measured from the wall decline this Winter.

One question I still have of temperature-related changes in the capacity bar display, are if they are a simply related to current battery temperatures, or if they also are the result of the LEAF's BMS varying the available percentage of total battery capacity.

Since the BMS cannot not foretell future temperatures, it would presumably have to make an estimate based on some period of past temperature experience, to limit future charge levels.

And we all have seen how well this principle works for range estimates from the GOM...

 

[RegGuheert]

Good point - I was assuming they meant short-term temperature change (i.e. change during one charge-discharge cycle) since that is what the page deals with, but you can certainly interpret that to include long-term effects, too.

I agree with your assessment. I just wanted to point out their unqualified statement. It certainly doesn't agree with some observations on this board of capacity bars coming and going with temperature.

 

[jspearman]

Met (ambushed) a guy driving a Silver Leaf in the parking lot of a Safeway in Scottsdale. He's not a member of the forum, but said he just lost his first bar at around 14K miles. I told him to check out this thread, since he said he's looked at the forum before. I didn't want to keep him too long, so that's all the info I have.

 

[opossum]

49.5 miles driven so far today. 5.1 miles/kWhr average. So I've used 9.7 kWhr. Plugged into L3 Blink. It said SOC was 63%. So 37% used. 9.7/0.37 = 15.4 kWhr. If you assume 21 kWhr is a new pack, we're at 73.4%. It's a toasty good time on the fast charger right now! The fun continues...

 

[mksE55]

49.5 miles driven so far today. 5.1 miles/kWhr average. So I've used 9.7 kWhr. Plugged into L3 Blink. It said SOC was 63%. So 37% used. 9.7/0.37 = 15.4 kWhr. If you assume 21 kWhr is a new pack, we're at 73.4%. It's a toasty good time on the fast charger right now! The fun continues...

Are you in Contact with your dealer, I would state this is direct proof your battery is shot and will not make the 5 year 20% or 10 yr 30% rule. Your actual mile capabilities is almost nearing, what economy cars get with 1 gallon of gas. I still dont know how you guys can drive in normal traffic and get 5.1mile/Kwhr. On my best slow day extra careful I was barely able to squeak out 4.6. I normally run 3.9. If I drove your car it would only make about 34 miles down the road. Complete failure as a car. What has your dealer said they are doing about this.

 

[Volusiano]

49.5 miles driven so far today. 5.1 miles/kWhr average. So I've used 9.7 kWhr. Plugged into L3 Blink. It said SOC was 63%. So 37% used. 9.7/0.37 = 15.4 kWhr. If you assume 21 kWhr is a new pack, we're at 73.4%. It's a toasty good time on the fast charger right now! The fun continues...

There's something wrong with what you're saying. I think you meant to say SOC was 37% remaining, 63% used. So 9.7/0.63 = 15.4 kwh. Otherwise, 9.7/.37 DOES NOT equal to 15.4 kwh.

Also, I think the L3 Blink will give you a much more optimistic SOC reading compared to the SOC bars on the LEAF. At least that's what I've observed many times when using the L3 Blink. So if you base your number of the L3 SOC, your battery remaining capacity will seem to be higher than if you base your number on the LEAF SOC bars.

I don't know which is more correct. I'm assuming that the L3 SOC is more correct because I'm guessing that the LEAF SOC bars are padded by Nissan to look worse than it is so that there's still some reserve left to lessen the risk of people running down their batteries sooner rather than later. Meanwhile, the L3 SOC does not need to be padded by Blink so it may be a more true measure. Just guessing here...

But the fact that your calculation comes out to 73.4% battery capacity is very close to your 3 bar loss (15+6.25+6.25)=27.5%. So that does seem to imply that the L3 SOC by Blink is more accurate than the SOC bars by the LEAF.

I'm curious whether you run AC or not, because 5.1 m/kwh is pretty darn good if you ran with AC, which I assume you need to being in Phoenix weather during a summer day.

 

[shrink]

I'm curious whether you run AC or not, because 5.1 m/kwh is pretty darn good if you ran with AC, which I assume you need to being in Phoenix weather during a summer day.

I got 5.0 m/kWh once this summer. All local driving on central Phoenix streets, A/C on, no highway, accelerating painfully slowly and keeping a steady speed. With a typical mix of highway and city driving here, we are usually around 4.2 to 4.5.

No idea how those guys can average over 5 locally. Impressive.

 

[DesertDenizen]

It is not difficult. My long term average is 5.6. I use the frontage roads instead of the highway so I don't exceed 45 mph. Exclusively Eco mode, don't use my breaks, just coast and get the regen. Plus I am much calmer and enjoy driving more. It becomes second nature.

 

[Stoaty]

It is not difficult. My long term average is 5.6. I use the frontage roads instead of the highway so I don't exceed 45 mph. Exclusively Eco mode, don't use my breaks, just coast and get the regen. Plus I am much calmer and enjoy driving more. It becomes second nature.

Agree. My lifetime average is 5.7, and my daily 40 mile round trip commute (90% of miles) involves 900 feet elevation gain on the way to work and 500 feet elevation gain on the way home (freeway goes over a hill). I drive 60% on the freeway, usually around 50-52 MPH (except when I have to slow down for traffic). Estimated extra time for driving this way is about 4 minutes each way, all time lost on the freeway. No time is lost on surface streets that I can tell.

 

[opossum]

Are you in Contact with your dealer, I would state this is direct proof your battery is shot and will not make the 5 year 20% or 10 yr 30% rule.

We've had our car at a dealership or the Nissan test facility roughly 5 times now. Each trip was useless (to us, the owners). We're now pursuing other options that have more potential benefit. We're about 2 steps away from resorting to driving the car through the front door of Mark Perry's office at full speed.

I still dont know how you guys can drive in normal traffic and get 5.1mile/Kwhr. On my best slow day extra careful I was barely able to squeak out 4.6. I normally run 3.9.

Precooling in the morning while plugged in. Minimal or no A/C on the way to work, provided I leave early enough and can get away with it. If necessary, I keep the A/C fan setting low (1 or 2 bars). My commutes are about 75% flat freeway. 58mph in the slow lane, provided I'm not pissing off lots of people. Slow down a bit on inclines, then speed back up on the declines. Timing lights and minimal braking on the city streets. Eco mode only. Today's first 50 miles did include a 1-way trek down SR-51, which gave me a handful of downhill miles. Otherwise, I would have probably been in the high 4s per kWhr.

There's something wrong with what you're saying. I think you meant to say SOC was 37% remaining, 63% used.

My bad. I transposed the two numbers, but the math part was correct. It must have been the heat being given off as my batteries were being fast-charged that put me in an altered mental state while I typed that on my phone.

But the fact that your calculation comes out to 73.4% battery capacity is very close to your 3 bar loss (15+6.25+6.25)=27.5%. So that does seem to imply that the L3 SOC by Blink is more accurate than the SOC bars by the LEAF.

It's also right in line with the range test we did before our car went to the Casa Grande facility, where our mileage to 1 SOC bar remaining was roughly 25-30% lower than the spec table from the Nissan bulletin.

 

[brettcgb]

:|

I lost my first battery capacity bar a week ago (about August 26, 2012). I noticed it after one of my infrequent 100% charges.
SOC bargraph now shows higher than battery capacity bargraph after 100% charge. Hmmm....

8500 miles, 2012 model year, leased Dec 20, 2011. Gilbert AZ (Phoenix Metro area). Contacted Nissan direct (not dealer), got a case number. Leasing is beginning to look better all the time.

I use L3 chargers about 6-8 times a month, and charge to 100% at home about as often. Home charging to 80% occurs after midnight, every night. During the hotter months, I've been enabling climate timer while on the charger, which also continues charging to about 90% typically.

Most of my driving is to/from work, about 15 miles each way, usually on side streets about 45 MPH, averaging about 4.6mi/kWHr, occasionally reaching 5.0mi/kWHr. Freeway driving is limited to 65 MPH (3.9-4.2mi/kWHr). Almost always in ECO mode (except when I notice it's not).

Once or twice a month, I take a trip to Glendale to visit parents (about 60 miles each way, with a stop on the way out). Carwings suggests that such round trips draw about 38kWHr. I've got modified "trickle" EVSE, so can charge from 240V (3.3kW) at parents - BIG help!

The last couple trips to parents have been... troublesome... each way, reaching VLB before reaching destination. At various times, I thought it was due to 1) Monsoon heat taking its toll on A/C, 2) brothers' driving technique on the last trip (but he drives a Prius and is "qualified"), then finally 3) Monsoon heat AND humidity.

Fortunately, there's now an L3 not far west of the mall in Scottsdale for the trip to Glendale in the afternoon (untried), and another in the ASU Research park (available 24/7, confirmed) for the return trip late in the evening.

Tangential story follows -----------
During the last trip to parents, got stranded at Bell Road Ford, planning on using the L3 DCFC. Got there with 6 miles range (indicated), 15 miles to go, and _ALL_ Blink chargers were non-functional (L3 powered off, one L2 failed self test, other L2 charged for 3-5 seconds before stopping). After panicking briefly :evil: (and forgetting there were other L2 chargers in range) one of the sales people pointed out a Ford branded L2 charger in front of showroom, but no one knew if it worked. After locating and turning on the power service switch, was able to charge for an hour and be on our way. Friendly sales people - got lit for Focus Electric (said little about electric systems, similar to Leaf).

Side comment - I'd really appreciate a J1772 charger at Scottsdale Fashion Square Mall. They've got a pair of Tesla HPC chargers (WTF?!? - 'xcuse the language).

 

[HXGuy]

Man, I don't know how you guys can drive how you do (referring to the slow driving). I've actually been trying to see how good my ICE cars can do mileage wise, which has meant driving no faster than the speed limit on the freeway (65 in a 65, 55 in a 55) and within 2-5 miles of the speed limit on surface streets and it feels like I'm driving SO slow, it's painful. All that and I was only rewarded with 32 MPG out of a tank of fuel on a diesel Mercedes E350. :?

 

[surfingslovak]

They've got a pair of Tesla HPC chargers (WTF?!? - 'xcuse the language).

You could get an adapter for those. It might cost a pretty penny, unless you went with something homegrown. The Tesla HPC should be pin-compatible with J1772.

 

[TonyWilliams]

:|

I lost my first battery capacity bar a week ago (about August 26, 2012). I noticed it after one of my infrequent 100% charges.
SOC bargraph now shows higher than battery capacity bargraph after 100% charge. Hmmm....

8500 miles, 2012 model year, leased Dec 20, 2011. Gilbert AZ (Phoenix Metro area). Contacted Nissan direct (not dealer), got a case number. Leasing is beginning to look better all the time.

Absolutely pathetic performance. I can't tell you how happy I am with a lease now. I charge every moment the car is in my garage and just drive. No stress!

 

[brettcgb]

They've got a pair of Tesla HPC chargers (WTF?!? - 'xcuse the language).

You could get an adapter for those. It might cost a pretty penny, unless you went with something homegrown. The Tesla HPC should be pin-compatible with J1772.

Thought about that, even did some research. Its possible to plug a J1772 charger into a Roadster HPC socket (I've seen this, and found adapters on the net), but to go from HPC plug to J1772 socket requires an HPC socket - these don't seem to be available anywhere.