Capacity Loss on 2011-2012 LEAFs

[Kataphn]

Just lost our first bar at 23,800 miles, 2 1/2 years. Car lives outside on the driveway half way between downtown Los Angeles and the beach. Mild climate. 80% charged 95% of the time.

 

[garygTx]

After hanging on for dear life as long as possible, bar 11 went to the big bit bucket in the sky. It is odd that it was there in the AM, but when I was leaving work it was gone. My AmpHr readings for yesterday were:

• 10/17 AM 51.3779
  10/17 PM 51.4041

It has continued dropping even though the summer heat is gone. I just hit 21,000 miles. I charge to 80% in the summer, but do 100% in the winter due to the wonderful heater. As a matter of fact, I will be returning the car at the end of the lease due to the range hit of the heater.

 

[opencar]

Seems right on time if we use Ahr as the best indicator of mapping to bar loss - glad you leased. thanks for posting this.

After hanging on for dear life as long as possible, bar 11 went to the big bit bucket in the sky. It is odd that it was there in the AM, but when I was leaving work it was gone. My AmpHr readings for yesterday were:

• 10/17 AM 51.3779
  10/17 PM 51.4041

It has continued dropping even though the summer heat is gone. I just hit 21,000 miles. I charge to 80% in the summer, but do 100% in the winter due to the wonderful heater. As a matter of fact, I will be returning the car at the end of the lease due to the range hit of the heater.

 

[Weatherman]

That is good information. I was curious as to when I would lose bar #11. Only a little over 3 Ahrs to go. Should be gone sometime early next year.

 

[bowthom]

Hello,
My Leaf continues it's rapid drop in capacity according to my Leaf DD. I am charging from VLBW (6.66 Ah) to 100% tonight. Need to find out if I have really lost this much capacity.
Edit: It took 19.7 kWh charging to 100%.

10/4/13


10/16/13 (12 days later 3.2 Ah gone at same temp!!)


10/20/13 Now 4 days later another Ah gone......


91 mV of variation for cell #16 (was ~ 50 mV a month ago)

 

[surfingslovak]

My Leaf continues it's rapid drop in capacity according to my Leaf DD. I am charging from VLBW (6.66 Ah) to 100% tonight. Need to find out if I have really lost this much capacity.

Thanks for sharing. It looks like you are still close to 63 Ah?

 

[RickS]

FYI I got my replacement pack on October 4th.

Cool! Did it have 12 capacity bars? Get any gid readings on a 100% charge? If you don't have the equipment, I'd imagine someone in your area can help you out.

Yes it's back to 12 bars, I haven't looked yet, but it should be a brand new 2013 pack. I also was pretty much forced to get the software update at the same time, but the range seems higher than it ever was when new. No GID reading equipment yet. I'm contemplating just selling it.

 

[bowthom]

My Leaf continues it's rapid drop in capacity according to my Leaf DD. I am charging from VLBW (6.66 Ah) to 100% tonight. Need to find out if I have really lost this much capacity.

Thanks for sharing. It looks like you are still close to 63 Ah?

Not sure where it really is but leaf DD says 58 Ah

 

[surfingslovak]

Not sure where it really is but leaf DD says 58 Ah

OIC - yes, it's on the photo second from last. Interesting. Are you seeing such a big swing due to a recently applied software update?

 

[bowthom]

Not sure where it really is but leaf DD says 58 Ah

OIC - yes, it's on the photo second from last. Interesting. Are you seeing such a big swing due to a recently applied software update?

Not sure, capacity has been falling like a stone. Last April (after 26 months of ownership) it was at 279 gids. Tonight it took 19.7 kwh to charge from VLBW to 100%.

 

[surfingslovak]

Not sure, capacity has been falling like a stone. Last April (after 26 months of ownership) it was at 279 gids. Tonight it took 19.7 kwh to charge from VLBW to 100%.

Yes, but GIDs in April do not necessarily mean much. The battery might have been down on capacity already, but this was masked by an overstated GID count. My LEAF was at 281 last April even though I measured 5% less range. The GID count then declined to 266 over the period of 2-3 months. How many GIDs do you see on a full charge these days? Your mileage is relatively low. How do you garage the LEAF?

 

[EricBayArea]

Unfortunately I just joined the club. 24 months almost exactly, 16,5xxx miles and 11 capacity bars

I haven't done a full 100% charge yet to get the stats, but "health" is reading 70.7%... FWIW.

 

[vrwl]

Unfortunately I just joined the club. 24 months almost exactly, 16,5xxx miles and 11 capacity bars

I haven't done a full 100% charge yet to get the stats, but "health" is reading 70.7%... FWIW.

My "health" is lower than that and I still haven't lost a bar, so what is your AHr reading at your first bar loss?

 

[TomT]

At this point, particularly after the P3227 update, I don't think we have any real idea what "Health" is or what it represents...

My "health" is lower than that and I still haven't lost a bar, so what is your AHr reading at your first bar loss?

 

[DaveinOlyWA]

Not sure where it really is but leaf DD says 58 Ah

OIC - yes, it's on the photo second from last. Interesting. Are you seeing such a big swing due to a recently applied software update?

Not sure, capacity has been falling like a stone. Last April (after 26 months of ownership) it was at 279 gids. Tonight it took 19.7 kwh to charge from VLBW to 100%.

Mine has been the same but like others, I had noticed somewhat less range as well. part of it was due to tire changes but also part was due to GIDs simply not going as far as before. Now, I did not get a GID meter until after a year so dont know what the very early days were like but did track my GIDs and noticed the first GIDs after a charge did not last nearly as long as GIDs in the middle of the pack.

But I have to say my GID readings this past Spring were inflated. Instead of being in the low 270's with an occasional 276-279, I am guessing it was more like the low to mid 260's. Now i am at the low 240's which leads me to guess (since i really cant do anything else) that I lost about 15-20 GID over the Summer which was the warmest since I got my LEAF by a wide margin.

Now, my GID count has rebounded somewhat since cooler weather along with my ahr and health. In my signature my goal is to post my weekly range and those numbers have gone up slightly over the past two weeks so we shall see where I am at come Spring

 

[vrwl]

At this point, particularly after the P3227 update, I don't think we have any real idea what "Health" is or what it represents...

My "health" is lower than that and I still haven't lost a bar, so what is your AHr reading at your first bar loss?

Agreed, that's the reason I asked OP for the Ahr reading, much more meaningful.

 

[EricBayArea]

I usually don't charge to 80%. However, I can provide Ahr and relative GID, SOC, etc. next time I go out to my car.

 

[bowthom]

Hello,
It makes me think that a heat event causes a permanent change in the rate of degradation. Put another way, each event increases the slope of the degradation curve. So even when temps have cooled down, we continue to see accelerated degradation. Those damaging effects are accumulative. It would explain a lot.

Just two weeks ago my 100% GID count was 260 now it's 248 at the same battery temp (20*C).
My leaf is parked outside but is in the shade in the afternoon when home. It is in the sun all day 3 times per week.

Last night's charge from VLBW to 100% = 19.7 kWh and took 5.4 hours.
My charger efficiency has historically been 87%.
19.7 x .87 = 17.1 kWh into the battery.
Figured another way:
3.3 kW per hour of charging, 3.3 kW x 5.2 hrs = 17.1 kWh (averaging the last .4 hrs of reduced charge rate).
Don

 

[GregH]

The true exact SOC might not be the same one day at VLBW as another.. On a discharge test a few days ago I noted that 1-2 Gid could produce a dramatically bigger cell voltage deviation.. Probably a better measure would be distance from average to low at the SAME average voltage (or pack voltage) on a different day..
For example I saw:
100mv (max-min) @ 21Gids, 350V
135mv (max-min) @ 18Gids, 347V
170mv (max-min) @ 14Gids, 339V
200mV (max-min) @ 10Gids, 335V
Once you get below 20-25Gids the lowest cells are dropping like rocks.. Might be more telling to measure (avg-min) @ avg (or Vpack)

In other news... unlike Bowthom, my capacity has been going UP this month!! Mostly due to lower temperatures I'm guessing (more likely to be 20-25C, 5TB now).
9/30 59.0793Ah 87.70Hx
10/4/ 59.1252Ah 87.79Hx
10/7 58.8628Ah 86.27Hx (well except here.. must have been a hot spell)
10/9 59.1908Ah 87.92Hx
10/15 59.6566Ah 88.84Hx
10/21 59.7944Ah 89.10Hx
This is still pre-P3227

 

[DaveinOlyWA]

I no longer use GIDs alone. This morning I was 245 but lost the first 5 GIDs in a mile which tells me that 245 was inflated. My "truer" GID count is probably 240. Not sure what benefit having ahr and health are but it does add more reference points along with batt temps