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Re: Capacity Loss on 2011-2012 LEAFs

Posted: Sat Feb 10, 2018 11:04 pm
by ixnay
I picked up a 2011 Ocean Blue SL with 0,000 miles last month, now 30,716 (so I'm driving double the former owner's monthly average)
According to LeafSpy Pro
166 GIDs
AHrs = 48.18;
SOH - 73.45
After last night's 80% charge, current SOC 78.1 (in part because I was detailing it today and had it powered on for a bit)

Bottom line: with my current efficiency, I can drive around 40 miles, getting 4.1-2/kWh. The GOM says 10 bars and 56 miles (was 58 at end of charge).

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Mon Feb 12, 2018 6:21 am
by RegGuheert
RegGuheert on December 14, 2017 wrote:Capacity degradation on our LEAF is now accelerating, with 2.6 Ah lost between 40,000 and 50,000 miles while we only lost 2.2 Ah between 30,000 and 40.000 miles. That is true even though the vehicle was driven those last 10,000 miles over a shorter period of time, so calendar losses during that last period should have been a bit lower.
So now I'm not so sure. As I reported previously, our LEAF has been showing increasing Ah readings recently. Since crossing 50,000 miles on December 7, 2017, at 47.21 Ah, the reported capacity has increased to 48.24 Ah on Februrary 11, 2018, with about 52,000 miles on the odometer.

So, has capacity loss accelerated from 2.2 Ah/10,000 miles (30,000 mi. to 40,000 mi.) to 2.6 Ah/10,000 miles (40,000 mi. to 50,000 mi.) or has it slowed to 1.6 Ah/12,000 miles (40,000 mi. to 52,000 mi.) or both?

Beats me, but I have a new theory about why the capacity has been increasing as of late. I think the BMS may be responding to our efforts to charge the battery to higher SOCs this winter by pressing the timer override button one or more times after the battery has completed its normal charge cycle. We started doing this because the combination of battery degradation (with the associated loss/reduction of regen), new tires and colder temperatures have made my wife's 50-mile commuted quite marginal this winter, even at temperatures of 20 degrees or more. Pressing the timer override button really DOES add more charge to the battery and I think the BMS interprets that as the battery having more capacity.

If that theory is correct, then I suppose when Spring comes around, we will get rapid reported capacity loss due to three different effects: 1) Loss of capacity due to no longer pressing the timer override button, 2) Loss of reported capacity as it warms up (It does that every year!), and 3) Loss of capacity that has been going on all along that has been masked by pressing the button.

We'll see. Perhaps the capacity loss reported over the 50,000- to 60,000-mile interval will shed some light on what is actually happening.

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Sun Feb 25, 2018 12:00 pm
by RegGuheert
RegGuheert wrote:
RegGuheert on December 14, 2017 wrote:Capacity degradation on our LEAF is now accelerating, with 2.6 Ah lost between 40,000 and 50,000 miles while we only lost 2.2 Ah between 30,000 and 40.000 miles. That is true even though the vehicle was driven those last 10,000 miles over a shorter period of time, so calendar losses during that last period should have been a bit lower.
So now I'm not so sure. As I reported previously, our LEAF has been showing increasing Ah readings recently. Since crossing 50,000 miles on December 7, 2017, at 47.21 Ah, the reported capacity has increased to 48.24 Ah on Februrary 11, 2018, with about 52,000 miles on the odometer.

So, has capacity loss accelerated from 2.2 Ah/10,000 miles (30,000 mi. to 40,000 mi.) to 2.6 Ah/10,000 miles (40,000 mi. to 50,000 mi.) or has it slowed to 1.6 Ah/12,000 miles (40,000 mi. to 52,000 mi.) or both?
Two weeks later, the Ah reading has dropped 1.0 Ah down to 47.28 Ah. It was 80F one day last week, so I guess it decided to head back down.

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Sun Feb 25, 2018 5:13 pm
by Valdemar
From my experience any gains in Ah are usually followed by a sharp drop to even lower levels.

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Sun Mar 04, 2018 5:29 pm
by Reddy
RegGuheert wrote:
RegGuheert wrote:
RegGuheert on December 14, 2017 wrote:Capacity degradation on our LEAF is now accelerating, with 2.6 Ah lost between 40,000 and 50,000 miles while we only lost 2.2 Ah between 30,000 and 40.000 miles. That is true even though the vehicle was driven those last 10,000 miles over a shorter period of time, so calendar losses during that last period should have been a bit lower.
So now I'm not so sure. As I reported previously, our LEAF has been showing increasing Ah readings recently. Since crossing 50,000 miles on December 7, 2017, at 47.21 Ah, the reported capacity has increased to 48.24 Ah on Februrary 11, 2018, with about 52,000 miles on the odometer.

So, has capacity loss accelerated from 2.2 Ah/10,000 miles (30,000 mi. to 40,000 mi.) to 2.6 Ah/10,000 miles (40,000 mi. to 50,000 mi.) or has it slowed to 1.6 Ah/12,000 miles (40,000 mi. to 52,000 mi.) or both?
Two weeks later, the Ah reading has dropped 1.0 Ah down to 47.28 Ah. It was 80F one day last week, so I guess it decided to head back down.
Reg, I measured my battery yesterday, first time since 11/1/17, and my reading went up slightly from 45.80 (41,700 mi) to 45.91 AHr (44,700 mi). I have increased my driving slightly (750 mi/mo vs. my previous 500 mi/mo normal), so maybe the battery likes being used more. I fully expect to see degradation increase again next month. I recorded about 2 AHr loss last year, and I’m expecting something similar this year. Hopefully it won’t be worse, though the summer could be brutal with more 115 F temps. I think I’m still on target to lose the 4th bar in 2019, so at about 8 years and right around 55,000 mi.

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Tue Mar 20, 2018 8:37 am
by Stanton
I've finally lost the first bar on my second (lizard) battery. The numbers (per LeafDD):

Months = 28
Miles = 22k
Ahr = 53.42
H = 72.61

Don't know why my "H" is so bad, but I still get decent range (70+ miles @4 mi/kWh).
This is better than my first battery...but only slightly :(

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Tue Mar 20, 2018 7:38 pm
by Marktm
Attached is the latest chart of amp-hr vrs time. This was a "lizard" battery replaced under warranty;
Battery log 3.14.18.jpg

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Wed Mar 21, 2018 3:22 am
by opencar
Stanton wrote:I've finally lost the first bar on my second (lizard) battery. The numbers (per LeafDD):

Months = 28
Miles = 22k
Ahr = 53.42
H = 72.61

Don't know why my "H" is so bad, but I still get decent range (70+ miles @4 mi/kWh).
This is better than my first battery...but only slightly :(
thanks for the info about the Lizard's 1st bar loss point: ~53Ahr. that's 2 Ahr below the original battery's 1st bar loss point; bar loss now seems even more like an arbitrary metric when i compare the two battery performances. sad to hear the improvement over the original battery is only slight at best.

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Wed Mar 21, 2018 12:33 pm
by ahagge
At the risk of being redundantly redundant, I'll re-post the degradation chart of my 2011 SL with a 2015 Lizard battery replaced in 2016 (1st bar dropped on 12/22/17 @ 52.29 AHr):

Image

Interactive version: https://docs.google.com/spreadsheets/d/ ... teractive/

Re: Capacity Loss on 2011-2012 LEAFs

Posted: Wed Mar 21, 2018 7:49 pm
by SageBrush
ahagge wrote: I'll re-post the degradation chart
NIce information, but regarding the Google Docs chart ...

How do you get a scale on both sides of the graph ? I've wanted that for a long time.

Also, I'm not able to open the interactive link.