Elmil
Posts: 142
Joined: Mon Oct 26, 2015 9:46 am
Location: Sweden

Re: Battery Ageing Model

Wed Nov 25, 2015 11:52 am

I have added a tab in the "Kia Soul EV CAN Messages" spreadsheet with data from a CHAdeMO charging session I did yesterday. Exactly the same thing happened as did at another QC a few days ago. I.e during the last 5-10 minutes until completion (83%), the Accumulative Discharge Energy counter started to count. This time it did 1.5kWh in 8 minutes. I am speculating that it might be due to cell balancing, but the power (11kW) seems too high. Any thoughts??
Kia Soul EV 2015 / 115,543 km Sold
Kia Soul EV 2019

JejuSoul
Posts: 1408
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Fri Nov 27, 2015 5:41 am

Hi Elmil, that is interesting data. I cannot explain it.
There is an interesting discussion of Chademo at the the German site here (in English)
http://www.goingelectric.de/forum/kia-s ... 1-120.html
I added a comment about you data.
Hope they have some ideas.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

goev
Posts: 79
Joined: Thu Oct 15, 2015 2:41 am
Location: Mandal, Norway

Re: Battery Ageing Model

Fri Nov 27, 2015 6:00 am

Jejusoul, can recuperation be the cause of the differences you see in your numbers?
If your car produced 14-15kWh in recuperation during driving, this would add up:

Cumulative energy charged: 35 from charging + 15 from recuperation = 50kWh
Cumulative energy discharged: 34 actually used "from battery" + 15 of the recuperated enegry = 49kWh.

This might also explain why the cumulative discharge/odometer is so high on my car: 21.62kWh/100km.

JejuSoul
Posts: 1408
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Location: Jeju
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Re: Battery Ageing Model

Sat Nov 28, 2015 7:05 am

goev wrote:Jejusoul, can recuperation be the cause of the differences you see in your numbers?
Interesting idea.
The Cumulative Energy counters are too high. Recuperation may explain it.
I will try to measure this by recording data coming down the mountain.

I have the same inconsistency as you in that the cumulative discharge/odometer reading does not match my trip reality.
I plotted it out to check : Only 1 month of data so no climate variation to view yet.
Image
The graph shows 21kWh/100km, my reality is between 13 and 14 kWh/100km.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

JejuSoul
Posts: 1408
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Sat Nov 28, 2015 7:11 am

Elmil wrote:I have added a tab in the "Kia Soul EV CAN Messages" spreadsheet with data from a CHAdeMO charging session I did yesterday. Exactly the same thing happened as did at another QC a few days ago. I.e during the last 5-10 minutes until completion (83%), the Accumulative Discharge Energy counter started to count. This time it did 1.5kWh in 8 minutes. I am speculating that it might be due to cell balancing, but the power (11kW) seems too high. Any thoughts??
I logged a Chademo session today. The Accumulative Discharge Energy counter did not change. The 96 cells were not balanced beforehand, but after charging I had a completely balanced pack for the first time since I have been recording data,
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

JejuSoul
Posts: 1408
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Battery Ageing Model

Sun Nov 29, 2015 6:09 am

I recorded a Chademo session again today. Some comments.
1. The Cumulative Energy Charged counter had increased between charges.
2. The efficiency of the charging seems to be about 94%
3. Again I did not see the Cumulative Energy Discharged counter alter during the charge.

It seems the Cumulative Energy counters do include the recuperation energy created during braking.
This renders the charts I have made for comparing cars useless, because driving style means each car will have a different proportion of recuperation.
The only good news is that for my own car the slope of the deterioration is a lot less than before.
I can't judge for any other car because I don't have the data.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

Elmil
Posts: 142
Joined: Mon Oct 26, 2015 9:46 am
Location: Sweden

Re: Battery Ageing Model

Mon Nov 30, 2015 11:10 am

I recorded another CHAdeMO session this weekend, with same result as before. Cumulative Energy Discharged counter started moving at the same level.

Today I found another anomaly, this time with the Cumulative Energy Charged counter...

- Recorded the drive to work all the way until shutdown of the car.
- Car parked all day (9+ hours) without any charging cable connected. Temperature 0C all day.
- First logged record after starting the car (still parked and unconnected) shows that the Cumulative Energy Charged counter had moved 0.4kWh during the day!

Which means that the battery was charged with 40W from nowhere, during all day....

Possible explanations:
- The BMC had buffered data still not accounted for when I turned off the car?
- The BMC made some sort of compensation after all load was removed and the battery voltage was allowed to float?
- Another cell balancing symptom?
- ?

It's pretty obvious in my logs that the Cumulative Energy Charged counter includes the recuperation energy, which is logical.
But there seem to be enough anomalies to be restrictive with interpretations of these numbers, as well as the deterioration values.
I will continue recording and we'll see if any pattern shows up. ;)
Kia Soul EV 2015 / 115,543 km Sold
Kia Soul EV 2019

JejuSoul
Posts: 1408
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Re: Battery Ageing Model

Sun Dec 06, 2015 9:34 pm

After not changing for 1500km my deterioration counters suddenly jumped yesterday.
I have driven 9800km in 7 months.
Before Yesterday: max 3.5% min 0.1%
Yesterday morning: max 4.5% min 4.4%
Yesterday evening: max 5.5 min 4.4%
I assume this is a calibration effect rather than something I did yesterday that caused deterioration to happen suddenly.
Whatever these numbers mean my car is now fairly similar in rate of deterioration to yours.

Yesterday I drove over the mountain on the fast road to record recuperation effect.
I drove 49km using 7.2kWh off the battery and recuperated 2.6kWh.
For this trip I got 27% of the energy from recuperation.

My car has a driving info screen under the UVO settings. I don't know if any of you have this function. Here is the display.
Image

I also posted this message on the German forum under the OVMS thread. That thread is quite busy and useful. http://www.goingelectric.de/forum/kia-s ... 1-130.html
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

Tom
Posts: 30
Joined: Sat Jul 18, 2015 1:37 pm
Location: Switzerland

Re: Battery Ageing Model

Sat Dec 12, 2015 1:07 pm

Elmil wrote:.... I.e during the last 5-10 minutes until completion (83%), ..... This time it did 1.5kWh in 8 minutes. I am speculating that it might be due to cell balancing, but the power (11kW) seems too high. Any thoughts??


This happens with my KIA all the time.
Needs from 80.9% to arround 83.0% arround 15 to 20 minutes (at all EVTEC 20KW station and the charger goes down until 2.2kW sometimes).
Charges easily 1.5kWh per percent (sometimes it is more in the 81%, sometimes more in the 82% range).
AND
At a 50kW ABB Tera station it will go only half the time and only goes down until arround 9 to 11kW.
I do not know if the longer time is a fault from the charger or not.
KIA Soul EV with vented seats and Chademo
Until July 2015 i-MiEV 13'500km
Summer 2015; Sold my all year arround used Cadillac Seville STS

JejuSoul
Posts: 1408
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
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Re: Battery Ageing Model

Tue Dec 15, 2015 12:35 am

Tom wrote:This happens with my KIA all the time...
What Elmil is referring to is the Cumulative Energy Discharged counter in the battery management system of the car itself. This counter goes up during the last portion of the charge. To graph battery ageing I use the Cumulative Energy numbers because I assume the deterioration is proportional to the use. That the numbers also include regeneration energy is fine, since this energy also counts as use. But am not sure if the increase Elmil has seen also counts as use. For now I'll ignore it and continue to graph data using the Cumulative Energy Discharged counter. Let's see if the graphs make sense when we compare them with actual range deterioration data. We don't have any yet - that's a future task - perhaps in two years time.

Some data we do have is the U.S. Advanced Vehicle Testing Activity from Phoenix, Arizona.
Phoenix is very hot. It is known to cause faster deterioration. (Especially to cars without thermal management of the battery = leaf)
None of the data we have for our Soul EVs is from a place as hot as Phoenix.
But that is where the testing center is and that is the data we've got.

Image

The trend lines are for the:
Ford Focus - 10% deterioration in 1 year driving 1000 miles a month.
2013 Leaf - 20% deterioration in 1 year driving 1000 miles a month.

The BMW seems to be on the same line as the Focus. (not enough data to make a trend yet)
Our data seems to be closer to the Focus than the Leaf. (but we don't know what scale our data is at yet)
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

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