lorenfb
Posts: 1802
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Mon Aug 14, 2017 10:09 pm

SageBrush wrote:
lorenfb wrote:So, the only Leaf battery data I concern myself with is Ahrs and battery output impedance (both LeafDD & LeafSpy
calculate), another measure of battery condition over time like with any battery type.

I'd like to hear your opinion:

LeafSpy gives me Ahr and Voltage numbers at the top of my cell voltage histogram. I presume the Ahr is extrapolated out to a full battery, while the voltage appears to be average cell voltage * 96. So e.g from the photo below 384.11*58.15/1000 = 22.33 kWh

If I charge to 100% and calculate the Ahrs*voltage, would that be an accurate kWh capacity of the battery ? I'm inclined to say no because the voltage decreases as the energy is consumed. But lets say that I knew the average battery voltage from 0 - 100% SoC. Could I then calculate an accurate usable kWh capacity ?

Image


Your approach is valid and accurate to evaluate the battery's energy at any point in time or for any SOC.

The battery voltage is nominally about 370 (96 X 3.85 volts) under partial load. The battery voltage drops very little
as the battery's Ahrs availability declines, i.e. reduced SOC, and also as the battery ages. So given that, why not just
be concerned with Ahrs and focus on monitoring that battery parameter exclusive of the nominal battery voltage.
Most likely if one would compare a near new battery with one that had lost 4 -5 bars (6+ years old), the voltage
difference would be less than 5 - 10%, i.e. battery life is all about loss of Ahrs.

One might conclude that your approach is more rigorous than just monitoring Ahrs when evaluating the battery's
condition. Personally, I find it easier when I power-on the Leaf after its overnight charge to immediately determine its
capacity as I begin my daily drive and during my drive. So by quickly knowing the Ahrs and my typical range of about
2 miles/Ahrs, I know the basic condition of the state of the battery when I need to be concerned about getting
to a charging station, if need be, and making it home without reliance on the Leaf's unreliable SOC or GOM.

Note: Your Leaf battery appears to be aging better than mine when it was at your mileage, i.e. mine was 55 Ahrs
and presently at 51 Ahrs @ 51K & 12 bars.
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

SageBrush
Posts: 2581
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Mon Aug 14, 2017 11:24 pm

lorenfb wrote:So given that, why not just
be concerned with Ahrs and focus on monitoring that battery parameter exclusive of the nominal battery voltage.

Fair point. I was trying to scrape up a few percent from somewhere to convince myself that I was not seeing a 1.5% monthly degradation.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

jbuntz
Posts: 134
Joined: Thu Dec 08, 2016 5:41 am
Delivery Date: 17 Dec 2016
Leaf Number: 303765
Location: New Braunfels, TX

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Tue Aug 15, 2017 6:03 am

I lost my first bar at 9,245 mi 61.68 AHr SOH 77% Hx 75.83
Mfg 11/15 Del 12/16 TX 2016 SL 30kWh,
Date Bar MI GID Ahr SOH
05/17 12 05175 324 70.75 89
08/17 11 09245 282 61.68 77
10/17 10 12000 260 57.22 71
01/18 09 15329 244 53.72 68
06/20 08 21716 230 50.41 63
06/27 11 22047 296 66.01 83 Aftr Updt

jbuntz
Posts: 134
Joined: Thu Dec 08, 2016 5:41 am
Delivery Date: 17 Dec 2016
Leaf Number: 303765
Location: New Braunfels, TX

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Tue Aug 15, 2017 6:08 am

cwerdna wrote:https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1591060294298139/ is a report of a 3 bar loser on a 30 kWh car. Post says location is Chandler, AZ, states car is 1.5 years old and shows 14,099 miles on the odo.


So he gets a new battery with the next bar loss?

Sam Backus, also from AZ, is reporting 3 bar loss in that same thread....
Mfg 11/15 Del 12/16 TX 2016 SL 30kWh,
Date Bar MI GID Ahr SOH
05/17 12 05175 324 70.75 89
08/17 11 09245 282 61.68 77
10/17 10 12000 260 57.22 71
01/18 09 15329 244 53.72 68
06/20 08 21716 230 50.41 63
06/27 11 22047 296 66.01 83 Aftr Updt

SageBrush
Posts: 2581
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Tue Aug 15, 2017 8:24 am

jbuntz wrote:I lost my first bar at 9,245 mi 61.68 AHr SOH 77% Hx 75.83

That sounds like another data point that points towards Nissan using a lower SoC before a bar is lost.

As for the other data, all I can is say is "ouch," but to clarify : your posted readings are from the time the bar was lost, right ?
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

jbuntz
Posts: 134
Joined: Thu Dec 08, 2016 5:41 am
Delivery Date: 17 Dec 2016
Leaf Number: 303765
Location: New Braunfels, TX

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Tue Aug 15, 2017 12:57 pm

SageBrush wrote:
jbuntz wrote:I lost my first bar at 9,245 mi 61.68 AHr SOH 77% Hx 75.83

That sounds like another data point that points towards Nissan using a lower SoC before a bar is lost.

As for the other data, all I can is say is "ouch," but to clarify : your posted readings are from the time the bar was lost, right ?


Yes, all bars visible the day before and it was on and off for a few days but now always off.
Mfg 11/15 Del 12/16 TX 2016 SL 30kWh,
Date Bar MI GID Ahr SOH
05/17 12 05175 324 70.75 89
08/17 11 09245 282 61.68 77
10/17 10 12000 260 57.22 71
01/18 09 15329 244 53.72 68
06/20 08 21716 230 50.41 63
06/27 11 22047 296 66.01 83 Aftr Updt

victorjsmith
Posts: 2
Joined: Thu Aug 17, 2017 12:45 pm
Delivery Date: 17 Oct 2016
Leaf Number: 309295

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Thu Aug 17, 2017 12:51 pm

My 2016, bought new 10 months ago, <10K miles just dropped a bar down to 11 bars. My offlease 2013 took 3 years and 30K miles to drop the first bar. Depressing.

SageBrush
Posts: 2581
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Thu Aug 17, 2017 3:41 pm

victorjsmith wrote:My 2016, bought new 10 months ago, <10K miles just dropped a bar down to 11 bars. My offlease 2013 took 3 years and 30K miles to drop the first bar. Depressing.

Yes, truly depressing.

So now your 30 kWh battery is like a new 24 kWh battery. Judging from other reports though, further degradation will be at a higher rate than the older 24 kWh technology. I suppose the only silver lining might be an increased likelihood of battery replacement under warranty.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

bakermel1
Posts: 8
Joined: Thu Dec 10, 2015 12:36 pm
Delivery Date: 09 Dec 2015
Location: Phoenix

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Thu Aug 17, 2017 5:53 pm

My 2016, purchased in Dec 2015, 30 kWh just lost it's 4th bar today at 29,800 miles in Phoenix. I took it to the dealer, they inspected it and are ordering a new battery. At this rate, I'll get a couple new batteries under warranty. I am looking forward to having more range again. I have been down to 60-70 miles for a full charge the last couple weeks.

jbuntz
Posts: 134
Joined: Thu Dec 08, 2016 5:41 am
Delivery Date: 17 Dec 2016
Leaf Number: 303765
Location: New Braunfels, TX

Re: 2016-2017 model year 30 kWh bar losers and capacity losses

Thu Aug 17, 2017 8:31 pm

bakermel1 wrote:My 2016, purchased in Dec 2015, 30 kWh just lost it's 4th bar today at 29,800 miles in Phoenix. I took it to the dealer, they inspected it and are ordering a new battery. At this rate, I'll get a couple new batteries under warranty. I am looking forward to having more range again. I have been down to 60-70 miles for a full charge the last couple weeks.


do you have leafspy data for when the bars dropped?
Mfg 11/15 Del 12/16 TX 2016 SL 30kWh,
Date Bar MI GID Ahr SOH
05/17 12 05175 324 70.75 89
08/17 11 09245 282 61.68 77
10/17 10 12000 260 57.22 71
01/18 09 15329 244 53.72 68
06/20 08 21716 230 50.41 63
06/27 11 22047 296 66.01 83 Aftr Updt

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