Post Your Battery Degradation Results

[hill]

...Makes me wonder who has driven the farthest so far with no bars lost...

Not quite what you're asking, but I presume that the record was TaylorSFGuy, who lost his first bar at 78,600 miles, 25 months, in WA. He seems to have gotten his money's worth out of his first LEAF! ..........snip..........

Wow! He sure kicked my arse right out of town.
:shock:
.

 

[kmp647]

45,000 miles 2012 SL delivered 11/11/11
Just lost bar 11 so 2 bars down
Bar 12 went at 41,000 miles earlier this year
Curr at 51ah

Northern va ( hot summers)

I used to have my evse on the outside of my garage so I had nighttime cooling
Moved an mounted my evse inside the garage,,,,, not good
Garage stays hot at night, ESP with a v8 ice parked in it.

I recommend outdoor night time charging

Car is still great though!

 

[RegGuheert]

45,000 miles 2012 SL delivered 11/11/11
Just lost bar 11 so 2 bars down
Bar 12 went at 41,000 miles earlier this year
Curr at 51ah

Last 6.25% of lost capacity took 1/10 as many miles as the first 15%.Perhaps you had P3227 update sometime around when the first bar disappeared?

Northern va ( hot summers)

But not so hot this summer. Certainly the first summer in your LEAF (2012) was the hottest with some 100-degree weather. This summer we had a couple of 95F days earlier and this last week saw 90F highs. No doubt last week sped things up for your second bar loss.

Since you won't likely lose any bars over the winter, you will likely run out of miles before you lose that fourth bar. Do you have the option to park it at ~58,000 to claim a new battery before warranty expiration? (I'm guessing not.)

I'm currently at 21,000 miles and haven't lost the first bar, yet, but it is getting close (55.4Ah currently).

 

[kmp647]

I have not been to the dealer and have not had the 3227 update.
I know it has not been a hot summer but my move to a new house and subsequent installation of the evse into the inside of the new gargage accelerated the degredation.

I wish I had a dual setup. Inside gargage evse for winter and fall , and outside for nighttime cooling/charging in late spring and all summer.

My lease is up in January at 49,000 miles so I am turning the car in !

 

[RegGuheert]

I have not been to the dealer and have not had the 3227 update.

Interesting. So you lost the last 6.25% capacity 10X faster than than the first 15% without a change in BMS firmware!

I know it has not been a hot summer but my move to a new house and subsequent installation of the evse into the inside of the new gargage accelerated the degredation.

Probably so, but I doubt that it accounts for the more-than-quadrupling of rate that you saw:

6.25%/4,000 = 1.56%/1000 miles
15%/41,000 = 0.37%/1000 miles
Ratio = 4.2:1

Of course, a big part of that difference in rate is because the last 6.25% was mainly during the summer. If each of the two previous summers were 6.25%, then they account for about 12.5% together. Since they were hotter, then perhaps they account for the entire previous 15%.

My lease is up in January at 49,000 miles so I am turning the car in !

Then I guess you have no worries!

 

[DaveinOlyWA]

45,000 miles 2012 SL delivered 11/11/11
Just lost bar 11 so 2 bars down
Bar 12 went at 41,000 miles earlier this year
Curr at 51ah

Northern va ( hot summers)

I used to have my evse on the outside of my garage so I had nighttime cooling
Moved an mounted my evse inside the garage,,,,, not good
Garage stays hot at night, ESP with a v8 ice parked in it.

I recommend outdoor night time charging

Car is still great though!

mine is mounted so I can easily park outside garage and charge. In fact the plug for the EVSE is about 6 feet from the garage door and is currently strung around and thru shelves to be positioned to be plugged in when parked in the garage. I do park outside every once in a while to charge but only because I am doing something that needs garage space. I have too much work equipment that I am too lazy to remove from the car to leave it outside at night although there is near zero security risk in my neighborhood.

 

[TomT]

Lost my third bar yesterday. It is now a race to see if I can loose the fourth bar before I turn the car in in March... To hasten the demise of the fourth, I have turned off the charge timer and will now charge to 100% each time (I pretty much need most of the 100% charge these days anyway with my current range)...

 

[garygid]

Lost the top capacity bar yesterday, at 20300 miles, 3 years and
5 months, in the mild winter but rather warm summer of Orange
County, CA.

From the GID meter, it appears that the useful full capacity is
(for now, in this hot weather where the car only charges to 91% SOC)
really down about 20%. Perhaps when the cooler winter temperatures
return, the car will again charge to around 95% SOC, and it will again
start using something like the top 4% of the usable capacity.

 

[DaveinOlyWA]

Lost my third bar yesterday. It is now a race to see if I can loose the fourth bar before I turn the car in in March... To hasten the demise of the fourth, I have turned off the charge timer and will now charge to 100% each time (I pretty much need most of the 100% charge these days anyway with my current range)...

must be nice!! I never lost a bar at all but degradation forced me to charge to 100% every day along with getting a boost on the road 2-3 days a week!

 

[Pipcecil]

I have had some interesting battery results in the past 2 1/2 months. I had my battery replaced July 2nd and the battery hit its peak value on July 15th (13 days later) at 100% SoH and 65.92 AHr. Since then the battery has done is gradual decline, averaging ~0.017 AHr per day to the end August. This is pretty spectacular as its the hottest part of the year (note I did NOT get a lizard battery). Unfortunately the stats change starting after August 31st. My AHr degradation increased to ~0.048 per day - a significant difference. I don't quite understand the behavior. The weather is definitely cooler than in July and August (despite it being a more mild summer). So why the increased capacity loss?

The ONLY thing that directly relates to this: multiple charging. I used to charge at work using Blink units everyday. I would only use ~65-70% of my battery to get to work (25 miles) but would charge for 2 hours to fill it back up. Then my car would sit for 7 hours fully charged before I drive it home. From our standard practices, to get the most out of the battery, it suggested to leave it charged @ 100% as little as possible. Now that CarCharging raised the rates ($2 per day now becomes $4.70 per day - so hell no), I don't charge at work anymore (this went into effect at the beginning of September). So far, unless there is something else going on, NOT charging my car twice a day (and leaving at 100% for many hours) is hurting the capacity more. My graphic plot of AHr shows a significant tilt down past August 31st. I would have originally attributed this to just an anomaly, but the trend has been going for over 2 weeks with showing signs of increasing the rate of loss.

Is there any other explanation for the sudden downward increase? Its been extremely consistent. Despite "normal" behaviors for Li-ion batteries, this seems to contradict the rules - it almost feels like Lead Acid - it wants to be charged up and topped off. As always, I will continue to track it daily, but I wanted some other minds thrown against the problem. The only other plausible explanation is that the battery finally "settled" and the original 1.5 months of loss were inflated (less loss) because the battery was settling still (despite it loosing AHr) and this is the true delta in loss that should be occurring, and the date of change, coupled with the change in charging habits was just a coincidence.

 

[dgpcolorado]

^ My capacity values fluctuate somewhat. A couple of weeks ago I had them go up by a tenth of an Ahr after I charged to 100% twice for the first time in three months; I presume that it had something to do with battery balancing. But, in general, I see small fluctuations in Ahr in warm temperatures on my 2012 battery, so I think that the calculation is based on factors that can vary depending on charge state.

At cold battery temperatures last winter my capacity stayed the same for months. No idea why temperature makes such a difference in the stability of the reading.

 

[DaveinOlyWA]

I have had some interesting battery results in the past 2 1/2 months. I had my battery replaced July 2nd and the battery hit its peak value on July 15th (13 days later) at 100% SoH and 65.92 AHr. Since then the battery has done is gradual decline, averaging ~0.017 AHr per day to the end August. This is pretty spectacular as its the hottest part of the year (note I did NOT get a lizard battery). Unfortunately the stats change starting after August 31st. My AHr degradation increased to ~0.048 per day - a significant difference. I don't quite understand the behavior. The weather is definitely cooler than in July and August (despite it being a more mild summer). So why the increased capacity loss?

The ONLY thing that directly relates to this: multiple charging. I used to charge at work using Blink units everyday. I would only use ~65-70% of my battery to get to work (25 miles) but would charge for 2 hours to fill it back up. Then my car would sit for 7 hours fully charged before I drive it home. From our standard practices, to get the most out of the battery, it suggested to leave it charged @ 100% as little as possible. Now that CarCharging raised the rates ($2 per day now becomes $4.70 per day - so hell no), I don't charge at work anymore (this went into effect at the beginning of September). So far, unless there is something else going on, NOT charging my car twice a day (and leaving at 100% for many hours) is hurting the capacity more. My graphic plot of AHr shows a significant tilt down past August 31st. I would have originally attributed this to just an anomaly, but the trend has been going for over 2 weeks with showing signs of increasing the rate of loss.

Is there any other explanation for the sudden downward increase? Its been extremely consistent. Despite "normal" behaviors for Li-ion batteries, this seems to contradict the rules - it almost feels like Lead Acid - it wants to be charged up and topped off. As always, I will continue to track it daily, but I wanted some other minds thrown against the problem. The only other plausible explanation is that the battery finally "settled" and the original 1.5 months of loss were inflated (less loss) because the battery was settling still (despite it loosing AHr) and this is the true delta in loss that should be occurring, and the date of change, coupled with the change in charging habits was just a coincidence.

probably the miles you are driving daily. don't get concerned over day to day trends. what is your kwh available say? besides, if you don't like your numbers, change them!

http://daveinolywa.blogspot.com/2014/09/manipulating-battery-stats.html" onclick="window.open(this.href);return false;

 

[keydiver]

I finally lost my second bar within the last day or 2, it took all summer to lose 4%:
28,733 miles
AHr = 51.55
SOH = 78%
Hx = 60.32%
206 GIDS (73.3%)
89.7% SOC at full charge
3 QC
2546 L1/L2
+-14mv (very balanced pack, all cells are aging equally)

 

[msandeep]

Folks,
Would it be possible to post your maximum observed range, along with your other stats? The other numbers are interesting, but at end of day what matters is whether the car will be usable a few years down the line. I am especially interested in hearing from people with 50K+ miles.

 

[Weatherman]

I finally lost my second bar within the last day or 2, it took all summer to lose 4%:
28,733 miles
AHr = 51.55
SOH = 78%
Hx = 60.32%
206 GIDS (73.3%)
89.7% SOC at full charge
3 QC
2546 L1/L2
+-14mv (very balanced pack, all cells are aging equally)

Second bar gone at 51.55? I think my capacity bars are stuck. Still 11 bars at 50.33. Doesn't matter. LEAF gets delegated to grocery store trips from now on. I'd like to give it back to Nissan, but they don't want it.

As for range, I wouldn't consider using it for a trip of more than about 45 miles after a full charge.

 

[lorenfb]

I finally lost my second bar within the last day or 2, it took all summer to lose 4%:
28,733 miles
AHr = 51.55
SOH = 78%
Hx = 60.32%
206 GIDS (73.3%)
89.7% SOC at full charge
3 QC
2546 L1/L2
+-14mv (very balanced pack, all cells are aging equally)

Second bar gone at 51.55? I think my capacity bars are stuck. Still 11 bars at 50.33. Doesn't matter. LEAF gets delegated to grocery store trips from now on. I'd like to give it back to Nissan, but they don't want it.

As for range, I wouldn't consider using it for a trip of more than about 45 miles after a full charge.

Your second bar will most likely 'drop' before you reach a capacity of 49 AHrs.

 

[dgpcolorado]

Folks,
Would it be possible to post your maximum observed range, along with your other stats? The other numbers are interesting, but at end of day what matters is whether the car will be usable a few years down the line. I am especially interested in hearing from people with 50K+ miles.

This just isn't practical. Range depends on driving conditions. One can do a range test using the standard conditions developed by Tony Williams (100 kph on relatively level terrain for as long as it will go on a full charge down to turtle) but this is very difficult to accomplish (and downright impossible where I live). [If you are talking about "range" as depicted by the "Guess-o-meter" (GOM) number on the fuel bars, that is a completely useless number of no validity whatsoever.]

So, speculating as to range would be a meaningless number. The critical number for battery degradation is Ahr (Amp•hours). The 2011/2012 LEAFs seemed to start out at 66.25 Ahr when new. Some 2013 and newer LEAFs sometimes show higher numbers, for reasons that are unclear, but likely have to do with the difficulty of measuring such things.

The Ahr readings can be used as a proxy for range: If you get a range of 70 miles under your driving conditions in a new LEAF, when your battery declines to 55 Ahr you could expect a range of about 58 miles.

But it isn't quite as simple as that because as the battery declines in capacity, the proportion of charge below Low Battery Warning (LBW) and Very Low Battery Warning (VLBW) will increase (since those warnings are at fixed charge levels). LEAF drivers who get spooked by the LBW will find their presumed range falling at a faster rate than the battery is degrading. That's because they are leaving an increasingly large proportion of the battery charge unused.

Sorry, posting "maximum observed range" just isn't a meaningful number.

 

[Wennfred]

Dropped 2nd Bar at 34274 Miles beginning of Sept. San Diego Ca. Sept is a record hot month here with Temps 90's - 100 and that's on the coast.

S: 93.2
C: 51.31
H: 59.78

211-214 GiDs

Back to driving in ECO mode, still getting 60 Miles. Work commute is 40 Miles round trip and I arrive with 89 GiDs & 20 Miles on the GOM.

Fred

 

[msandeep]

No need to speculate - just report what you see. I believe this problem lends itself well to some statistical analysis. I can think of a number of a number of independent variables - battery age (in miles), average speed, top speed, average summer temperature, beginning and ending SOC. The dependent variable would be miles traveled. Given enough data points, it might be possible to build a regression model that predicts the range at the 90% confidence level. The key would be to get enough people to respond and enter data accurately.

This just isn't practical. Range depends on driving conditions. One can do a range test using the standard conditions developed by Tony Williams (100 kph on relatively level terrain for as long as it will go on a full charge down to turtle) but this is very difficult to accomplish (and downright impossible where I live). [If you are talking about "range" as depicted by the "Guess-o-meter" (GOM) number on the fuel bars, that is a completely useless number of no validity whatsoever.]

So, speculating as to range would be a meaningless number. The critical number for battery degradation is Ahr (Amp•hours). The 2011/2012 LEAFs seemed to start out at 66.25 Ahr when new. Some 2013 and newer LEAFs sometimes show higher numbers, for reasons that are unclear, but likely have to do with the difficulty of measuring such things.

The Ahr readings can be used as a proxy for range: If you get a range of 70 miles under your driving conditions in a new LEAF, when your battery declines to 55 Ahr you could expect a range of about 58 miles.

But it isn't quite as simple as that because as the battery declines in capacity, the proportion of charge below Low Battery Warning (LBW) and Very Low Battery Warning (VLBW) will increase (since those warnings are at fixed charge levels). LEAF drivers who get spooked by the LBW will find their presumed range falling at a faster rate than the battery is degrading. That's because they are leaving an increasingly large proportion of the battery charge unused.

Sorry, posting "maximum observed range" just isn't a meaningful number.

 

[keydiver]

Would it be possible to post your maximum observed range, along with your other stats?

After a 100% charge this morning, I believe the GOM showed either 62 or 64 miles, but on arriving back home this afternoon, after driving 44 miles, the GOM showed 10 miles remaining (in ECO mode).