Battery Ageing Model

[mtndrew1]

Did a 100% - 2% - 100% cycle yesterday.

Current numbers:

MIN 12.6%
MAX 15.0%
CEC 14196
CED 13584
MAX CELL# 3
MIN CELL# 19

ODOMETER 41649 MILES / 67028 KM

 

[SoulEV2016]

Update from my car :

 

[Tom]

Still collecting numbers?

Max. Det. 7.5% , Cell #2
Min. Det. 6.5% , Cell #25

Batt. tmp. 27 °C (and it is sommer here)

ODO close to 30'000 Kilometer

Drive/SOC habitats:
I do not force the car really and drive in ECO mod 99% of the time
Usually exept for balanceing once a moth or so do not charge over 80% (more in winter when I need 100% for the roundtrip (selden).
I leave the car parked never with any SOC below 20% (usually 25%).
Charge a lot 50kW DC and drive it often to arround 13% SOC (in winter sometimes even to arround 8%) direct to the 50kW DC station and load up to arround 75% usually.
I drive and charge so my battery is not getting warmer then 40°C.

 

[SoulEV2016]

Update.

 

[JejuSoul]

Still collecting numbers?

Yes. I'm still collecting the numbers. Thanks for posting them.
All of the cars participating in the collection of data on this thread are doing well. No major battery problems.
For instance my car is over 2 years old, has driven nearly 40,000km and is still at SOH = 100%. I am nearing the end of the 10% buffer, so I expect to begin to see a small decrease in range over the next year.

But there are now plenty of stories of massively decreased range, battery failure and / or severe battery degradation leading to battery replacement on other threads. We have very little data on these failed cars, so we can't really say why.

An example is here - Evie zeroed out at 53 miles and UPDATE!! Evie's battery replacement complete!

 

[JejuSoul]

-
Yet another case of sudden degradation of the battery in California requiring battery replacement. Is this 6 cases now?

From last week -
71.2%. Decreased from 79.6% down to 71.2% over 3 weeks. Still does not meet the threshold for a battery warranty, but the dealership kept the car and said they will talk to Kia tomorrow because of the rapid battery deterioration.
see comment on Facebook Forum

This week the car is below 70% and the battery replacement is authorised.
Sudden degradation like this is presumably cell failure or a faulty BMS. But these problems do seem very common.

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Here in Korea there are two similar cases.

First - this car SOH = 62.7% is waiting for the battery replacement.



Second - this car SOH = 79.8% went in to get checked in July.
By August the SOH was 72%. Kia initially said yes, then refused.
I assume the 70% value will be hit next week.




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I don't have many details on how these cars were driven, or any long term battery data. So as yet no conclusions as to why these cars are failing, but none of the cars we are monitoring are. As a point of reference 10 of the 20 cars we are measuring battery data for have had an OBC replacement. Am guessing that the OBC error is randomly distributed and that it has occurred about half the time in cars 2 or 3 years old. Battery failure however is either very rare or is not randomly distributed. Am guessing the latter. Am assuming it is something similar to this - see http://www.mykiasoulev.com/forum/viewtopic.php?p=7277#p7277

Just in case people start to panic reading the above. There are a couple of things you should know.

1). The OP has 67,000 miles (107,000kms) on a car that is just over a year old.

2). They seem to charge extensively on a rapid c harger (level 3)

Obviously lots of highway driving being done and rapid charges.

This is extreme for any electric car. An EV is ideal for around town with some highway. The higher current draws from highway will (depending on average speed) accelerate battery degradation. Couple this with the higher amperage push on a level 3 c harger and you have a recipe for even more degradation. If you combine both of these activities frequently (long trips) you are Definitely going to see accelerated battery degradation.

These are city cars not cross country commuters...

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To add to the list of battery failures leading to replacement. This 2015 car in Quebec - 110,000km. see Presque trois ans et des maux de tête...

 

[teirhy]

2 years, 45 000 km :

 

[JejuSoul]

2 years, 45 000 km : SOH = 102.2%

teirhy - thanks for the data.
Your car is doing well - slightly better than mine. (2 years, 40 000 km : SOH = 101.7%)
Also good recent data from Elmil here - http://www.mykiasoulev.com/forum/viewtopic.php?f=6&t=677&start=30#p7335
(2 years, 75 000 km : SOH = 99.7%)

There is an interesting poll on the N issan L eaf sister site - Poll : Number of miles before losing the first bar



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Here's the official SOH for my car at recent service

 

[SoulEV2016]

interesting to compare my OpTime (2500h-16000km) and the teirhy OpTime (2500h-45000km). :mrgreen:

 

[JejuSoul]

-
This post is copied from the Facebook thread here - https://www.facebook.com/groups/SoulEV/permalink/1472647756149166/

Over 103000km and still able to break the 200km/charge mark in the summer. I'm interested to see how the battery holds up over 200,000km....which should be in about 2 years
...
I hypermile the car all day every day (consistent throttle, efficient speed, best route etc). I'm not sure what actually helps the car most, but I need this battery to make 350000km so I try everything.
I only charge to 100 when I need too. I never leave the battery at 100 for more then an hour. And when I charge, I do it in stages...1am=80%, 430am=100%. That way the battery doesn't get to warm, it won't sit at 100% to long, and the battery will be at operating temp as soon as I leave to work. During the winter I purposely have the battery charge finish right before I leave to work so that it's still warm and I don't spend any energy warming it up.
I have never quick charged.
I try not to charge it if the car, or outside air temp is too warm. If it's really warm I use 120v.
I always drive in B.
I barely use any climate function.
In city driving, I've done over 200km many times. Summer average on rural roads is about 185k. I've never had less then 120km even in the winter. Winter average is 135-150km. Except twice I've driven the car at very high speed for a long duration, and the range dropped substantially.
My approach has been- EV batteries are still new, and much of what we learn is good for them hasn't truly been time tested. So to protect my investment, I put a lot of thought into whats good for the car.

 

[SoulEV2016]

Update of my car.

Note : from the beginning of this lease, i use my proper EVSE electronic to charge this car.
I have never use the Kia official charger cord provide with my car.

https://www.ev-power.eu/Electric-Cars/EVSE-kit-for-EV-charging-station.html

 

[mtndrew1]

I turned my Soul back into Kia and my final readings were:

Odometer: 45,030 miles
CEC: 15,391
CED: 14,749
Min det: 12.6%
Max det: 15.0%
Min cell: #19
Max cell: #3

 

[JejuSoul]

I turned my Soul back into Kia and my final readings were:...

Thanks Andrew, Good luck with your new car. As with all the rest of us on this thread your car shows very little deterioration after 3 years. (It would show SOH = 97.5%)

However there are 2 really good ways to destroy the battery fast. 1/ Leave it at 100% charge in Arizona summer. 2/ Drive at high speed for a long distance every day. There's another one of these on the facebook thread.

... It's SOH is 70.4%. Only 47,000 miles in my 2015, commuting 90 miles a day.

 

[Tom]

After 8 Weeks standing around with 63% (and little yellow switch in OFF position during this time) and shortly after from 16 to 100% charged I have new numbers:
Km: 31'650
Max Det: 9.9%
Min Det: 8.4%

It looks to me like: I do not like to standing around without getting used

 

[Elmil]

2½ years, 79500km:

Max det: 10.6
Min det: 8.3

Dashed vetical line is BMS update/reset.

 

[user 892]

Hi there,

I'm from Germany and I found this discussion via a link that JejuSoul posted in the German goingelectric.de forum.

One week ago I bought a used Soul EV from an BEV veteran. The car was built in November 2015 and registered in July 2016. In between it was presented in a dealer's showroom. The odometer reading is 34,000 km. According to the previous owner, the car has been only very occasionally Chademo charged, mostly it has been charged at home at 24A (about 5.5kW). Since the car was used constantly by the whole family, it was charged to full almost every day, but it was never left alone for several days with 100% or low SOC.

I already charged it three times to 100% using the Kia supplied charger. In a couple of weeks I'll get a wallbox which allows me to charge with 3.7kW.

Yesterday I checked the battery status with Torque and got the values shown below. From what I've learned reading this topic, my battery is below average for it's age, right? Should I be worried?

Is my assumption correct that the battery lost between 10.6 and 13.1 percent of it's gross capacity, so now all further losses occur against the net capacity?

Regards
Frank

 

[JejuSoul]

...Yesterday I checked the battery status with Torque and got the values shown below. From what I've learned reading this topic, my battery is below average for it's age, right? Should I be worried?..

No. Don't Worry. Your car still has 98% SOH. It is doing fine.

Here's the data for my car. May 2015, 42,500km.



Currently charges to 180km on a full charge. Same as new. Max Det = 11.5% Min Det= 9.8% => Computed SOH = 99.35%
I got a new OBC fitted today so asked Kia to check the battery stats => Actual SOH = 99.2%
Good to confirm that our numbers computed in Torque match the 'real' data.



There are 2 cars on this thread doing amazingly well, but the other 20 are all doing much like mine. We are not going to get a new battery under warranty. But if the line stays linear we are only just going to go over the 10 year 160,000km warranty limit. I still assume though that it will degrade less as the car gets older, primarily because you won't drive so far, or so fast.

It is becoming very clear though that the users on this thread are unusual in that we are all looking after our battery health. I have seen / heard numerous reports from USA / Canada / South Korea of cars with very serious battery degradation. These users do the opposite. Charge to 100%, drive like they stole the car, often down to the very bottom of the battery. These batteries are being replaced after 2 or 3 years.

 

[user 892]

Meanwhile I forced a calibration by loading from 9% to 100%, as suggested earlier in this thread. SOH is now back to 100.8%, deterioration values are 8.1 / 9.1 / 10.2. Usually, I load the car up to 80% SOC only, unless I know that I'd need the fully capacity the next day.

I envy you guys for the 10 years of warranty. Here in Germany it is 7 years only.

Regards
Frank

 

[goev]

Hi guys!

Thank you for all your work on this matter! It was a very interesting read. I've incorporated the SOH-calculation into the upcoming OVMS v3.
My own numbers are max detoriation 17.2% and min 15.6% after 59928.2Km.

Regard,
Geir

 

[Tom]

Hi guys!

Thank you for all your work on this matter! It was a very interesting read. I've incorporated the SOH-calculation into the upcoming OVMS v3.
My own numbers are max detoriation 17.2% and min 15.6% after 59928.2Km.

Regard,
Geir

Hy Geir

good to see you back!
I am looking forward to your next OVMS version.