msandeep
Posts: 15
Joined: Tue Sep 16, 2014 7:16 pm
Delivery Date: 25 Oct 2013
Location: San Francisco Bay Area

Re: Tuning the Battery Aging Model

Mon Sep 22, 2014 9:29 pm

Curious - why does the Miles Per KWH change from summer to winter? I thought this metric was independent of the battery state. Is it due to heating/cooling?

hjaime
Posts: 4
Joined: Fri May 16, 2014 12:09 am
Delivery Date: 25 Aug 2011
Leaf Number: 007942

Re: Tuning the Battery Aging Model

Mon Sep 22, 2014 9:46 pm

Air conditioning eats up battery

leafedbehind
Posts: 173
Joined: Sat Apr 30, 2011 9:49 am
Delivery Date: 11 Sep 2011
Leaf Number: 8198
Location: Mountain View, CA

Re: Tuning the Battery Aging Model

Tue Sep 23, 2014 1:13 pm

Update on my 3 year old leaf:
Date - 9/23/2014
11 capacity bars (lost first bar in April 2014 @20,700 miles)

Delivered - Sept 11, 2011
Manufactured - July 2011

Location - Mountain View, CA
Miles/kwh - 3.9
Odometer - 23,187
Capacity - 54.6054 AHr
LeafDD "H" - 67.86

Almost always charge to 80%. Car often garaged at home -- detached garage can get warm. Battery aging model pretty close to my experience with this car, if I plug in 7 days/week in the sun (that's really an overestimation of how long it is in the sun).
2011 SL-e, silver, VIN 8198, delivered 11 Sep 2011. 37k miles, ~200 GIDs, 9 bars (1st bar lost 3 April 2014 @20,700 mi, 3rd bar lost Aug 2017)
2015 e-Golf SEL
2013 Fit EV, VIN 151, delivered 17 Nov 2012, lease return Nov 2015 at 30k miles
7.7kW solar PV

cwerdna
Posts: 9814
Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Tuning the Battery Aging Model

Tue Sep 23, 2014 10:56 pm

msandeep wrote:Curious - why does the Miles Per KWH change from summer to winter? I thought this metric was independent of the battery state. Is it due to heating/cooling?
hjaime wrote:Air conditioning eats up battery
As does the heater. This was esp. true of the power hungry resistive heater in the '11 and '12 Leafs. I'm not clear if the '13 Leaf S' resistive heater is more efficient but the hybrid heater in the '13+ SV and SL helps for many folks.

Also, during winter, there's more likely to be rain, slush or snow, which increases rolling friction, thus reducing efficiency further.

'19 Bolt Premier
'13 Leaf SV w/premium package (owned)
'13 Leaf SV w/QC + LED & premium packages (lease over, car returned)

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

tivollix
Posts: 65
Joined: Wed Apr 03, 2013 6:56 am
Delivery Date: 18 Mar 2013
Leaf Number: 006065

Re: Tuning the Battery Aging Model

Wed Sep 24, 2014 4:12 am

The main reason is that air density increase when as temperature decrease.
cwerdna wrote:
msandeep wrote:Curious - why does the Miles Per KWH change from summer to winter? I thought this metric was independent of the battery state. Is it due to heating/cooling?
hjaime wrote:Air conditioning eats up battery
As does the heater. This was esp. true of the power hungry resistive heater in the '11 and '12 Leafs. I'm not clear if the '13 Leaf S' resistive heater is more efficient but the hybrid heater in the '13+ SV and SL helps for many folks.

Also, during winter, there's more likely to be rain, slush or snow, which increases rolling friction, thus reducing efficiency further.
2016 Leaf since 21000KM.
2015 for 30000KM
2011 Black SL Leaf. Demo. In service: 2013/03
Sold at 38000 KM

User avatar
RegGuheert
Posts: 6419
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: Tuning the Battery Aging Model

Wed Sep 24, 2014 6:48 am

tivollix wrote:The main reason is that air density increase when as temperature decrease.
At lower speeds, air density has very little effect on energy consumption.

OTOH, when it is 10F outside, the heater might consume as much electricity as the drivetrain. This is particularly true at lower speeds, and is not influenced by the presence of a heatpump at such low temperatures.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

tivollix
Posts: 65
Joined: Wed Apr 03, 2013 6:56 am
Delivery Date: 18 Mar 2013
Leaf Number: 006065

Re: Tuning the Battery Aging Model

Wed Sep 24, 2014 11:03 am

Ok, I just referred to the law of physics and common sens. Also when it is 10F I am not using the cabin heater when not connected to the wall power.
Sure a 6KW heater is using 6KW when it is 10F outside, that why we have heated seats that use 50W instead...
Also many people forget that ICE car consumption can go from 50MPG in summer to 40MPG in winter, at least up North.

RegGuheert wrote:
tivollix wrote:The main reason is that air density increase when as temperature decrease.
At lower speeds, air density has very little effect on energy consumption.

OTOH, when it is 10F outside, the heater might consume as much electricity as the drivetrain. This is particularly true at lower speeds, and is not influenced by the presence of a heatpump at such low temperatures.
2016 Leaf since 21000KM.
2015 for 30000KM
2011 Black SL Leaf. Demo. In service: 2013/03
Sold at 38000 KM

TimLee
Posts: 2811
Joined: Thu Jan 20, 2011 9:40 am
Delivery Date: 17 May 2011
Leaf Number: 2026
Location: Chattanooga, TN

Re: Tuning the Battery Aging Model

Wed Sep 24, 2014 11:20 am

tivollix wrote:...
Sure a 6KW heater is using 6KW when it is 10F outside, that why we have heated seats that use 50W instead...
Not all LEAFs have heated seats.

And many people don't like the car cabin at 10F, even if they have heated seats.

The most significant factor on winter efficiency is heat.
Second most is snow / rain.
Air density is a much less significant factor.

Tim Lee
Chattanooga, TN

Man. Date: 03/10/11, VIN # 2026
Delivered 05-17-2011
Blue Ocean, 2011 SL-eTec

tivollix
Posts: 65
Joined: Wed Apr 03, 2013 6:56 am
Delivery Date: 18 Mar 2013
Leaf Number: 006065

Re: Tuning the Battery Aging Model

Wed Sep 24, 2014 11:37 am

Your are pretty sure of your affirmation but we agree on the factors. Case closed.

Not everybody is using the car the same way and it is fine.

In my case I am not using much the heater when driving to preserve range.
But what do I know, Quebec is not that cold ;)
TimLee wrote:
tivollix wrote:...
Sure a 6KW heater is using 6KW when it is 10F outside, that why we have heated seats that use 50W instead...
Not all LEAFs have heated seats.

And many people don't like the car cabin at 10F, even if they have heated seats.

The most significant factor on winter efficiency is heat.
Second most is snow / rain.
Air density is a much less significant factor.
2016 Leaf since 21000KM.
2015 for 30000KM
2011 Black SL Leaf. Demo. In service: 2013/03
Sold at 38000 KM

thimel
Posts: 133
Joined: Fri Apr 23, 2010 6:10 pm
Delivery Date: 11 Jun 2011
Location: SF bay area

Re: Tuning the Battery Aging Model

Fri Oct 10, 2014 9:55 pm

Just lost my second capacity bar. So time for an update

Manufactured - 05/11
Delivered - 6/11/11
P3227 updte - 9/14/13
Location - Sunnyvale, CA (near San Jose)
Miles/kwh - 4.2
Odometer - 32209
Capacity - 51.57
Date - 10/10/14
Parked in sun - 5 days/week in Palo Alto

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