The 40KWH Battery Topic

I’m going through my 3mo update now. Currently at 91.62 soh.
2018 with 4,170 miles. And try keeping it in the 30-75 soc range. Doesn’t matter what I do, still drops.

My degradation basically slowed to a crawl and the seasons had nothing to do with it since it started in April. I traded it in at 25,000 miles and so will be starting the monitoring all over. FYI; on my E Plus, yesterday, I hit 99.66% SOH which is where my 40 kwh started. This should be interesting.

Looks like I have hit my three month update as my SOH took a big drop this morning. I know there has been speculation that winter shuts down the updates, and my daily drop rate had slowed to a crawl, but still getting a 3 month big adjustment. In a day or two when its done I'll post updated stats but I'm down below 93% now.

California's version of Winter likely doesn't even register on the BMS.

LeftieBiker said:

California's version of Winter likely doesn't even register on the BMS.

Click to expand...

Depends where in California - IIRR the record low was -45 deg. F, at a reservoir near Truckee in 1935. I once spent a night a few miles away when that same spot hit -37. I don't know just how cold it was where we were, but my -20 deg. F. rated windshield washer fluid had turned to the consistency of a Slurpee in the reservoir, and wouldn't flow through the hoses to the washer nozzles when I wanted to clean the ice off the windshield. Ridgecrest is sort of middling, being inland, high dry desert with a record low of -17C/1.4 deg. F. Its climate isn't Mediterranean like the coast or Central Valley, but it's not the mountains either: https://en.wikipedia.org/wiki/Ridgecrest,_California#Climate

LOL

My average battery temp the last month has been running around 45-48F or so depending on the time of day.
We actually had snow a week or two ago here.

But certainly its not THAT COLD around here in the winter.

Battery / BMS is continuing its 3 month adjustment, now down to 92.34%.


Doesn't the fact that (for some) winter shuts down the adjustments or the BMS tell us with certainty (AKA CONCLUSIVELY) that the LACK of thermal management is causing issues for the battery? why else would the BMS slow down adjustments when it is cold?

So we just need to keep the battery at about 20F and it would last forever....

danrjones said:

LOL

My average battery temp the last month has been running around 45-48F or so depending on the time of day.
We actually had snow a week or two ago here.

But certainly its not THAT COLD around here in the winter.

Battery / BMS is continuing its 3 month adjustment, now down to 92.34%.


Doesn't the fact that (for some) winter shuts down the adjustments or the BMS tell us with certainty (AKA CONCLUSIVELY) that the LACK of thermal management is causing issues for the battery? why else would the BMS slow down adjustments when it is cold?

So we just need to keep the battery at about 20F and it would last forever....

Click to expand...

Stop listening to what 24 and 30 kwh LEAFers have to say. Your pack is simply different. But the "real" difference is the BMS. Its simply reporting information using a completely different set of rules. I had my biggest negative adjustment happen during the coldest part of the year which coincides with the time of year I did least amount of driving (2717 miles in 3 months).

Then Summer came, I road tripped, cooked the pack, drove 4599 miles in 90 days, hit 12 temperature bars for the FIRST TIME EVER a few times. Did a QC compatibility test of Webasto which was 9 charging stops in one day exceeding 500 miles and my pack stats WENT UP.

With all that in mind; the real question becomes "how well do you think you can predict what your pack will do in the next year?"

You are at 92.30something % SOH? Well, that is about where I was after 21 months of ownership after being at 92.5% after 15 months...

But I am not alone. There are now dozens of us and we all seem to be between 15-21 months and 91 to 93% SOH. We live ALL OVER the World and have rampantly different driving habits, demands and needs.

A year is a long time; What do you think your SOH will be on July 4th?

DaveinOlyWA said:

danrjones said:

LOL

My average battery temp the last month has been running around 45-48F or so depending on the time of day.
We actually had snow a week or two ago here.

But certainly its not THAT COLD around here in the winter.

Battery / BMS is continuing its 3 month adjustment, now down to 92.34%.


Doesn't the fact that (for some) winter shuts down the adjustments or the BMS tell us with certainty (AKA CONCLUSIVELY) that the LACK of thermal management is causing issues for the battery? why else would the BMS slow down adjustments when it is cold?

So we just need to keep the battery at about 20F and it would last forever....

Click to expand...

Stop listening to what 24 and 30 kwh LEAFers have to say. Your pack is simply different. But the "real" difference is the BMS. Its simply reporting information using a completely different set of rules. I had my biggest negative adjustment happen during the coldest part of the year which coincides with the time of year I did least amount of driving (2717 miles in 3 months).

Then Summer came, I road tripped, cooked the pack, drove 4599 miles in 90 days, hit 12 temperature bars for the FIRST TIME EVER a few times. Did a QC compatibility test of Webasto which was 9 charging stops in one day exceeding 500 miles and my pack stats WENT UP.

With all that in mind; the real question becomes "how well do you think you can predict what your pack will do in the next year?"

You are at 92.30something % SOH? Well, that is about where I was after 21 months of ownership after being at 92.5% after 15 months...

But I am not alone. There are now dozens of us and we all seem to be between 15-21 months and 91 to 93% SOH. We live ALL OVER the World and have rampantly different driving habits, demands and needs.

A year is a long time; What do you think your SOH will be on July 4th?

Click to expand...

Good info

Actually I have only had the vehicle for 7 months, but it depends on if you count time it was sitting on the dealer lot or not. As of this AM I am at 92.13% so it is still doing its adjustment.

Where will I be July 4th? I do not know. My guess is into the 80's. But you could easily be correct as well. I do not think its even been proven that we are watching "Real" SOH.

danrjones said:

DaveinOlyWA said:

danrjones said:

LOL

My average battery temp the last month has been running around 45-48F or so depending on the time of day.
We actually had snow a week or two ago here.

But certainly its not THAT COLD around here in the winter.

Battery / BMS is continuing its 3 month adjustment, now down to 92.34%.


Doesn't the fact that (for some) winter shuts down the adjustments or the BMS tell us with certainty (AKA CONCLUSIVELY) that the LACK of thermal management is causing issues for the battery? why else would the BMS slow down adjustments when it is cold?

So we just need to keep the battery at about 20F and it would last forever....

Click to expand...

Stop listening to what 24 and 30 kwh LEAFers have to say. Your pack is simply different. But the "real" difference is the BMS. Its simply reporting information using a completely different set of rules. I had my biggest negative adjustment happen during the coldest part of the year which coincides with the time of year I did least amount of driving (2717 miles in 3 months).

Then Summer came, I road tripped, cooked the pack, drove 4599 miles in 90 days, hit 12 temperature bars for the FIRST TIME EVER a few times. Did a QC compatibility test of Webasto which was 9 charging stops in one day exceeding 500 miles and my pack stats WENT UP.

With all that in mind; the real question becomes "how well do you think you can predict what your pack will do in the next year?"

You are at 92.30something % SOH? Well, that is about where I was after 21 months of ownership after being at 92.5% after 15 months...

But I am not alone. There are now dozens of us and we all seem to be between 15-21 months and 91 to 93% SOH. We live ALL OVER the World and have rampantly different driving habits, demands and needs.

A year is a long time; What do you think your SOH will be on July 4th?

Click to expand...

Good info

Actually I have only had the vehicle for 7 months, but it depends on if you count time it was sitting on the dealer lot or not. As of this AM I am at 92.13% so it is still doing its adjustment.

Where will I be July 4th? I do not know. My guess is into the 80's. But you could easily be correct as well. I do not think its even been proven that we are watching "Real" SOH.

Click to expand...

Yeah as far as when the clock starts is a good question but mine spent zero time on the lot with build date 1/2018 picked up 2/16/18. My first adjustment happened after 74 days so if we assume it was 16 days from manufacture until my delivery date at the dealership...

My prediction for you? Still in the 90's. Maybe another 1% based on your much warmer climate.

My guesstimate of the effect of time before first sale is that if the car isn't fully charged, the loss is tiny. If it is sitting at 100%, or the climate is hot (or both), then the loss is more substantial.

Number four of eight from:
"8 lessons about EV battery health from 6,300 electric cars" by
Bradley Berman
- Dec. 14th 2019 1:23 pm ELECTREK webpage on Google News

"liquid-cooled batteries decline slower than air-cooled packs.
Geotab saw that a 2015 Tesla Model S with liquid cooling had an
average annual degradation rate of 2.3%, compared to an air-cooled
2015 Nissan Leaf’s rate of 4.2%."

Bouldergramp said:

Number four of eight from:
"8 lessons about EV battery health from 6,300 electric cars" by
Bradley Berman
- Dec. 14th 2019 1:23 pm ELECTREK webpage on Google News

"liquid-cooled batteries decline slower than air-cooled packs.
Geotab saw that a 2015 Tesla Model S with liquid cooling had an
average annual degradation rate of 2.3%, compared to an air-cooled
2015 Nissan Leaf’s rate of 4.2%."

Click to expand...

Not that he's wrong, but you can't compare batteries of two different chemistries based on another factor like thermal management alone.

LeftieBiker said:

Bouldergramp said:

Number four of eight from:
"8 lessons about EV battery health from 6,300 electric cars" by
Bradley Berman
- Dec. 14th 2019 1:23 pm ELECTREK webpage on Google News

"liquid-cooled batteries decline slower than air-cooled packs.
Geotab saw that a 2015 Tesla Model S with liquid cooling had an
average annual degradation rate of 2.3%, compared to an air-cooled
2015 Nissan Leaf’s rate of 4.2%."

Click to expand...

Not that he's wrong, but you can't compare batteries of two different chemistries based on another factor like thermal management alone.

Click to expand...

Agreed and if you bothered to look at other LEAFs, you would find that the 24 kwh packs were the only ones that degraded below the average curve line.

Good point, the 17 Leaf is actually doing better than the 16 Tesla S.

https://storage.googleapis.com/geotab-sandbox/ev-battery-degradation/index.html

Wow do you have some good comparison articles on that Doug, I'd like to save those and perhaps share them. I am assuming it was in more moderate climates.

So I finally seen my first increase in SOH (that I have noticed - usually take reading one every month or two)... here are the last 3 readings


Oct 21, 2019 Kilometers/Miles; 35500/22116 Ahr; 104.6 SOH; 90.61
Nov 15, 2019 Kilometers/Miles; 37018/23062 Ahr; 104.54 SOH; 90.56
Dec 14, 2019 Kilometers/Miles; 38703/24111 Ahr; 105.07 SOH; 91.02

Date SOH% SOH %Chg Ahr Ahr %Chg TempF

3/15/19 97.47 -2.53% 112.52 -2.53% 69.1
4/15/19 97.41 -2.59% 112.45 -2.59% 75.2
5/15/19 97.34 -2.66% 112.37 -2.66% 82.2
6/15/19 95.38 -4.62% 110.11 -4.62% 90.8
7/15/19 94.98 -5.02% 109.64 -5.02% 97
8/15/19 94.63 -5.37% 109.24 -5.37% 101.8
9/15/19 94.41 -5.59% 108.99 -5.59% 92.2
10/15/19 94.26 -5.74% 108.81 -5.74% 81
11/15/19 93.71 -6.29% 108.18 -6.29% 52.5
12/15/19 93.67 -6.33% 108.13 -6.33% 60

12,000 miles. Build date is 2/18 and in-service date is 3/15/19. This battery, so far, is actually doing slightly better than my 2015 lizard pack based on the leafspy numbers. I lost my first bar at ~45000 miles on that car after 3.5 years in service and 4.5 years after it was built. Overall I am very happy with this 2018... if it were faster I'd probably keep it until it died.

My three month adjustment finished putting me at 91.78% Currently have just under 3500 miles.


Date SOH AMPHr Hx
05/03/2019 97.63 112.70 97.50
05/06/2019 97.62 112.69 97.94
05/07/2019 97.61 112.68 98.03
05/10/2019 97.60 112.67 98.39
05/13/2019 97.59 112.66 98.55
05/15/2019 97.58 112.65 98.73
05/19/2019 97.57 112.63 98.84
05/27/2019 97.55 112.61 99.27
06/01/2019 97.53 112.59 99.61
06/04/2019 97.50 112.55 100.12
06/11/2019 97.44 112.48 101.03
06/12/2019 97.43 112.47 101.25
06/13/2019 97.42 112.46 101.25
06/14/2019 96.49 111.39 101.58
06/15/2019 96.28 111.15 101.58
06/16/2019 95.64 110.41 101.67
06/17/2019 95.42 110.15 101.82
06/19/2019 95.40 110.13 102.15
06/20/2019 95.38 110.11 102.25
07/15/2019 95.19 109.89 103.22
07/24/2019 95.10 109.78 104.04
08/11/2019 94.90 109.55 104.95
08/30/2019 94.73 109.36 106.05
09/05/2019 94.68 109.30 106.27
09/10/2019 94.65 109.26 106.45
09/11/2019 94.64 109.25 106.48
09/12/2019 94.50 109.09 106.47
09/13/2019 93.73 108.20 106.48
09/14/2019 93.30 107.71 106.45
09/15/2019 93.29 107.69 106.45
09/17/2019 93.28 107.68 106.42
09/19/2019 93.27 107.67 106.41
09/23/2019 93.25 107.65 106.25
09/29/2019 93.23 107.62 106.50
10/16/2019 93.19 107.58 105.56
10/21/2019 93.19 107.58 105.34
10/23/2019 93.18 107.57 105.20
10/27/2019 93.16 107.54 105.15
11/05/2019 93.16 107.54 105.08
11/11/2019 93.15 107.53 104.88
11/14/2019 93.14 107.52 104.83
11/15/2019 93.14 107.52 105.07
11/18/2019 93.13 107.51 105.37
11/20/2019 93.12 107.50 105.52
12/05/2019 93.12 107.50 106.04
12/10/2019 93.11 107.49 106.14
12/11/2019 92.90 107.24 106.10
12/11/2019 92.76 107.08 106.10
12/12/2019 92.34 106.60 106.12
12/13/2019 92.13 106.35 106.10
12/14/2019 91.78 105.95 106.09
12/16/2019 91.78 105.95 106.03

Bouldergramp said:

Number four of eight from:
"8 lessons about EV battery health from 6,300 electric cars" by
Bradley Berman
- Dec. 14th 2019 1:23 pm ELECTREK webpage on Google News

"liquid-cooled batteries decline slower than air-cooled packs.
Geotab saw that a 2015 Tesla Model S with liquid cooling had an
average annual degradation rate of 2.3%, compared to an air-cooled
2015 Nissan Leaf’s rate of 4.2%."

Click to expand...

Says more about Bradley Berman than it does about liquid vs passive cooling.

https://storage.googleapis.com/geotab-sandbox/ev-battery-degradation/index.html

Notice that the Soul EV, air cooled, has very low degradation, at least in this data base.

Notice that the LEAF 2012, worst battery, has very low degradation, the lowest of any LEAF, at least in this data base. LEAF 2013 was BETTER than LEAF 2015, at least in this database. Explain that.

Ah, maybe there is some factor not being shown. Or maybe the data is just not very good.

My almost two year old (2020 soon ) 40kWh pack is sitting at 95,5% SOH, it's in a very cool climate.