dwl
Posts: 77
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

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

Sun Jun 10, 2018 3:36 am

johnlocke wrote:As an owner of a 2016 4 bar loser, I can tell you that my experience is that the Leaf spy numbers matched the actual usable mileage fairly closely. For the last year I've been routinely driving the car to LBW or less fairly regularly. LBW is a fixed number of GID's (50) so I've watched the LBW creep up from 13% to 21% of power left when the nice lady announces LBW. Range has steadily dropped over time,

I agree 50 GIDs is LBW but the issue is where on the voltage curve it is occuring as the GIDs are based on measurement and calculations. It is my understand that as the capacity of a battery declines, the knee tends to stay around the same voltage but occurs at a lower Ah value. The portion of the battery capacity after the knee may hold a relatively constant amount of energy.

If the 50 GID point occurs at an increasing voltage as the battery degrades, or even just as BMS recalculates and places it higher, then the effective capacity as seen by the driver degrades. The only way to confirm this is to do a full discharge under controlled conditions to explore usable kWh remaining below LBW and indications are there is more than the 4kWh suggested by LBW.

At least you are getting a new pack so will have range fully restored. Thanks for the feedback.
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

jbuntz
Posts: 129
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

Sun Jun 10, 2018 8:34 am

Back in October I got mine down to 4 GIDs. Pack voltage 282.56. The voltages min/avg/max were 2.83/2.943/3.065 My SOH at the time was 71% Hx 70.24% AHr 56.92 odo 12168. What are others voltages at turtle??
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: 2488
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

Sun Jun 10, 2018 11:52 am

dwl wrote:
LeftieBiker wrote:
There are indications in tests here in New Zealand that some 2016 cars are under reporting capacity as presented in SOH and lost bars.

All of the available evidence shows that the batteries are losing capacity rapidly, not under-reporting it. This is an important distinction, as it means a real physical deterioration of the packs, as opposed to a software glitch in the BMS.

The amount of charge accepted from flat by several cars seems to be significantly more than would be expected from the AHr/SoH and kWh reports from Leaf Spy (simply relaying car BMS). If drivers only go down to LBW or VLBW they may experience the reduced capacity as these indications seem to be triggering at higher than expected voltages on some cars.

If there is evidence that confirms the total holding capacity is reduced, not just capacity down to the warning levels, references would be appreciated. I accept there will be cars that have lost more capacity and there will be variability across the whole fleet.

If we use the value from Nissan of 31.78kWh from empty, would we expect to only be able to put in SoH * 31.78kWh at 240V and 15A ? There might be calibration errors in the EVSE kWh reporting but the example I gave was the car accepted a lot more than would be expected for the SoH (87% vs 76% reported SoH). Unfortunately only using down to LBW and VLBW can show reported loss of capacity which might not be actual.

One of the effects of a degraded battery is increased resistance. So while 27.7 kWh may have been pulled from the meter, the charging losses are uncertain, as is the fraction of energy stored in the battery from the charging event.
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

dwl
Posts: 77
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

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

Sun Jun 10, 2018 2:30 pm

SageBrush wrote:One of the effects of a degraded battery is increased resistance. So while 27.7 kWh may have been pulled from the meter, the charging losses are uncertain, as is the fraction of energy stored in the battery from the charging event.

This is definitely a consideration during rapid charging. For 16A I put the following words in our local forum post: "if we use 0.1 ohm as 100% ESR (conservative, I think the 30kWh are less), the approximate charge current at 360V is 9A so that loss would 9*9*0.1=8.1W * 7.7h = 0.06kWh. If we assume 72% Hx is now 0.139 ohm, the extra loss might be 9*9*0.04=3.2W * 7.7h = 0.025kWh extra - i.e. very little and probably much bigger instrumentation errors." and got a response "100mR would be about right for a 24kWh car, I believe the newer batteries might be a bit better and the 30kWh car should be better linearly with capacity"

A further response was: "Given that loss is current squared times resistance, it's linear with resistance. Hx is 1/resistance so 72% Hx is 1.39* the original ESR. Assuming the time doesn't change (which it won't unless the ESR gets REALLY bad) then the difference will be 39% more for the 72% Hx car. Where it plays more of a role is total round-trip efficiency. It's not such a big deal when charging at 10A, but is a bit worse when discharging at 50A (current squared and all that jazz) and much much worse when charging at 120-140A. It will add nonlinearities depending on the type of charging/discharging. At a 50kW charge rate, you're looking at 1.9kW of loss (~96% efficient) for the 100% Hx and 2.7kW of loss (94.5% efficient) for the 72% Hx."
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

SageBrush
Posts: 2488
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

Sun Jun 10, 2018 3:44 pm

^^
That looks pretty convincing. Thanks
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

dwl
Posts: 77
Joined: Tue Jan 05, 2016 5:06 pm
Delivery Date: 08 Jan 2016
Leaf Number: 112097
Location: New Zealand

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

Sun Jun 10, 2018 3:57 pm

An interesting post on Facebook at https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1982145841856247/. He was down two bars and a Nissan dealer did "Recall PC630 LEAF 30KW BATTERY, NTB18 NISSAN RECALL PROGRAMMED HV BATTERY AS PER RECALL.". Now back to 12 bars. While it could be a simple reset it sounds like more.
2014 S - 6000 km Jan 2016; 45000 km May 2017 95% SoH; 68,000 km Mar 2018 90% SoH

vishvik
Posts: 5
Joined: Wed Mar 07, 2018 12:27 pm
Delivery Date: 07 Jul 2016
Leaf Number: 312128
Location: Atlanta, GA

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

Mon Jun 11, 2018 6:57 am

Lost my 4th bar today :( 26K miles. Leased it new 1 year and 11 months back. Contacted a local Nissan dealer and made a service appointment for this Friday. I do have LeafSpy but not sure what to look for. Can someone please point out? Thanks!

jbuntz
Posts: 129
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

Mon Jun 11, 2018 8:55 am

vishvik wrote:Lost my 4th bar today :( 26K miles. Leased it new 1 year and 11 months back. Contacted a local Nissan dealer and made a service appointment for this Friday. I do have LeafSpy but not sure what to look for. Can someone please point out? Thanks!
Swipe right to the cells page and record the AHr SOH Hx and cell difference in mV at full charge.
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

Reddy
Posts: 1496
Joined: Fri Feb 11, 2011 3:09 pm
Delivery Date: 18 Aug 2011
Leaf Number: 006828
Location: Pasco, WA

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

Mon Jun 11, 2018 12:12 pm

dwl wrote:An interesting post on Facebook at https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1982145841856247/. He was down two bars and a Nissan dealer did "Recall PC630 LEAF 30KW BATTERY, NTB18 NISSAN RECALL PROGRAMMED HV BATTERY AS PER RECALL.". Now back to 12 bars. While it could be a simple reset it sounds like more.
Great, now we have Nissan reprogramming 2016-7 batteries (not that we shouldn't expect it since they did the same to the 2011-2 batteries). :(
Reddy
2011 SL; 9 bar, 45.80 AHr; 45,000 mi; rcv'd Aug 18, 2011
Long: http://www.mynissanleaf.com/viewtopic.p ... al#p226115"
Cold: http://www.mynissanleaf.com/viewtopic.p ... 60#p243033"

WetEV
Posts: 2090
Joined: Fri May 04, 2012 8:25 am
Delivery Date: 16 Feb 2014
Location: Near Seattle, WA

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

Mon Jun 11, 2018 1:30 pm

Reddy wrote:
dwl wrote:An interesting post on Facebook at https://www.facebook.com/groups/nissan.leaf.owners.group/permalink/1982145841856247/. He was down two bars and a Nissan dealer did "Recall PC630 LEAF 30KW BATTERY, NTB18 NISSAN RECALL PROGRAMMED HV BATTERY AS PER RECALL.". Now back to 12 bars. While it could be a simple reset it sounds like more.
Great, now we have Nissan reprogramming 2016-7 batteries (not that we shouldn't expect it since they did the same to the 2011-2 batteries). :(


Yes. Soon followed by releasing a new battery chemistry (the "lizard") with more acceptable life. I'm interested, as I might want to buy a used Leaf in a few months or so. History doesn't repeat, but it rhymes.
WetEV
#49
Most everything around here is wet during the rainy season. And the rainy season is long.
2012 Leaf SL Red (Totaled)
2014 Leaf SL Red

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