Battery Ageing Model

[JejuSoul]

...Now my SOH dropped to 64.7%. I do not know if the warranty covers my KIA, the car is imported from USA-California, I do not think that KIA middle east will accept a warranty claim. ...

Hi Omar,
No, I do not think Kia Jordan will cover the battery warranty for a car privately imported from the USA.
I have seen another query like yours from a Soul EV imported from Korea.
Kia will not cover battery failure in these cases.

I do know of a repair facility in Amman that has 'fixed' Soul EV batteries in the past. - مركز انفيرتر : الألكتروني: Electronic Inverter Center
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[JejuSoul]

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The SOH on my 2nd car has now dipped below 70%. Less than 3 months ago I bought this car with 85%. It's now 69.5%.
Really sudden degradation. In the same 3 month period my original car has not degraded at all.
The rate of deterioration seems to be accelerating in the last week, even though the weather is cooler and I'm driving slower.
But I do need to charge more often.
I took it in to the local Kia today. Official reading 69.5%.
Battery replacement is done at the main center. I have to book an appointment because there is a waiting list.









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[JeroenE]

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Really sudden degradation. In the same 3 month period my original car has not degraded at all.
The rate of deterioration seems to be accelerating in the last week, even though the weather is cooler and I'm driving slower.
But I do need to charge more often.

I hope you get your replacement soon!

I find it disconcerting that the battery deterioration seems to go very fast all of a sudden with 'lots' of cars. I hope this doesn't mean there is something wrong with the battery design.

Does it look like there are one or two cells that are getting really bad in your car too?

 

[Omar]

First to update you on my car. The battery seems like recovering some range gradually!, now its consumption is back at around 39% per my daily commute (last year it was 37%, 2 weeks ago it was 43 - 45%).
But max deterioration, min deterioration and SOH still read the same. (4.4%, 43.8%, 64.7% respectively).

About the quick drop in the battery performance, it is in fact a kind of normal if 1 cell or more performs worse than the others. This is because of the battery way of connection and the battery chemistry.
Once a cell deteriorates, its voltage jumps while charging. The car BMS avoids overcharging the cell, so it stops the charging once it is over a certain limit. This is to protect the cell from more damage. So, other good cells will not reach their full charge. All the good cells lose a portion of their capacity. This means that the capacity loss will be amplified 96 times!, the same happens at the low charge level as well!.
another observation supports this claim!, when I start driving from home, the car loses the first 2% very quickly! while the total estimated range stays the same!, because the percentage of charge shown on the car screen is dependent directly on the max cell voltage. Once I drive some distance, the voltage jump disappears. and the percentage of charge drops more logically with distance
This is still a theory, I am doing more reading and learning about the battery technology, that would be in line with my plans to study sustainable energy systems in the future !

I monitored my car, on time the jump of the bad cell was higher, so other cells were charged up to 4.10V, another time the jump was a little less, so half of the cells reached 4.12V.

 

[Omar]

Why does the BMS suddenly notices the battery performance change?

1. It can happen if some kind of resetting happens to your BMS. It happened with me after I disconnected the 12 volts battery for 8 hours in order to fix an issue with the clock!
2. If your battery charge is regularly in the middle range like between 30 or 40% - 80%, your BMS is less likely to detect a bad cell, the bad cell normally behaves bad at the top and the bottom of the charging range!. So if you stay in the middle, then for a day or two you charge your car to 100% then discharge it to a low level, the BMS will realize the problem.

 

[JeroenE]

Once a cell deteriorates, its voltage jumps while charging. The car BMS avoids overcharging the cell, so it stops the charging once it is over a certain limit. This is to protect the cell from more damage.

I understand that 1 cell can make an entire battery-pack useless.

But what I don't understand is that the cell keeps deteriorating, even if the BMS is doing it's best to protect it.

Note that in my car the first 15% with my bad battery were almost identical to driving with a good battery. Only when the charge was below 84% the percentages were dropping much faster than they should with regards the distance travelled.

 

[ksoul2084]

First to update you on my car. The battery seems like recovering some range gradually!, now its consumption is back at around 39% per my daily commute (last year it was 37%, 2 weeks ago it was 43 - 45%).
But max deterioration, min deterioration and SOH still read the same. (4.4%, 43.8%, 64.7% respectively).

About the quick drop in the battery performance, it is in fact a kind of normal if 1 cell or more performs worse than the others. This is because of the battery way of connection and the battery chemistry.
Once a cell deteriorates, its voltage jumps while charging. The car BMS avoids overcharging the cell, so it stops the charging once it is over a certain limit. This is to protect the cell from more damage. So, other good cells will not reach their full charge. All the good cells lose a portion of their capacity. This means that the capacity loss will be amplified 96 times!, the same happens at the low charge level as well!.
another observation supports this claim!, when I start driving from home, the car loses the first 2% very quickly! while the total estimated range stays the same!, because the percentage of charge shown on the car screen is dependent directly on the max cell voltage. Once I drive some distance, the voltage jump disappears. and the percentage of charge drops more logically with distance
This is still a theory, I am doing more reading and learning about the battery technology, that would be in line with my plans to study sustainable energy systems in the future !

I monitored my car, on time the jump of the bad cell was higher, so other cells were charged up to 4.10V, another time the jump was a little less, so half of the cells reached 4.12V.

This matches my own observations well.

 

[Omar]

This morning, I checked my battery cell map before I started driving. It was surprising to me that most of the cells charged up to 4.06V only. The bad cell was at 4.18V. (the car shows 100% charge). in a new battery they must reach 4.14/4.16 V. Recently they were reaching 4.10V.
So what was different today?
First, the battery was at lower level than usual when I started charging (22% compared to usual 40%).
Second, I charged the car in one shot. Normally when I charge the battery to 100%, I do it in 2 stages, using 2 timers, with a "rest" of about 2 hours in the middle.
Third, the weather was colder by around 6 C.

 

[JejuSoul]

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Spoke to Kia about my replacement battery.
Good news is that it is a 3 hour fix. I get to keep driving the car beforehand.
But there is only 1 service center on the island that can do it.
And the bad news is that there is a 2 month waiting list. ( 50 cars perhaps. 3% of the older Soul EVs here) .

This is unusual. Previously I would hear about 1 car every few months needing a replacement.
Perhaps this spike in failures happened because of sudden deterioration during the summer.

I am certain that we get new packs, not refurbished.
The old packs are taken to a recycling center and the cells taken out and put into ESS storage units.
I don't know yet, how many cells are in the new packs.

 

[JejuSoul]

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Am still waiting to hear from Kia about when I can take my car in to get the battery replaced.
I am still driving the car as normal.
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In the Torque codes we use to measure the SOH I have two different calculations for measuring the SOH.
The original version uses the average of MIN and MAX deterioration values.
This works well when the battery is in good health. ( But only slightly better than the other version.)
But fails completely when the battery goes 'bad'.

The 'new' version ignores the MIN deterioration values.
This version works well in all cases.
I suggest users prefer this version at all times.
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Here's the MIN and MAX deterioration values graphed over the last 4 months for my car that is waiting to get the battery replaced.
The MIN deterioration value is chaotic and trending down. It cannot be used in any calculation that makes sense.



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For various reasons I am no longer going to collect and publish the data from cars other than my own on this thread.
The 20 cars I had monitored were all doing well, and it seemed like the batteries would last a long time.
But it has become obvious that a very substantial number of other cars are requiring replacement batteries under warranty.
The subset of drivers that measured their battery data from the start is clearly unusual.

I believe Kia recognized the fact that many batteries were failing and would soon need replacement years ago.
It helps understand why Kia stopped selling EVs in the American market and focused almost entirely on Norway.
Norway - the one place where climate and driving conditions mean a substantial number of battery packs will survive.
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[Zattaxu]

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I believe Kia recognized the fact that many batteries were failing and would soon need replacement years ago.
It helps understand why Kia stopped selling EVs in the American market and focused almost entirely on Norway.
Norway - the one place where climate and driving conditions mean a substantial number of battery packs will survive.
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There have been reports of failing battery packs also in Norway. As some owners has had their cars 5 years (first cars were delivered autumn 2014) many owners has reached 100.000 km (appx 60.000 miles) or more. I don't know the percentage which have claimed replacement, (Norw. warranty: 70 % capacity after 150.000 km/7 years), but my impression from Norw. EV forums/Facebook groups is that a lot of owners of the cars which have passed 100.000 km are experiencing degradation problems. Some have had their battery packs replaced after waiting up to 6 monts on a new pack.

My car (registered November 2014) started showing signs of degradtion at appx 80.000 - 90.000 km and according to the Soul EV Spy app, SOH is now at 76,1 %, down from 82,1 % just a few months ago. It seems degradation is happening faster now than ealier.

 

[Oinq]

But now, the winter is coming, I suppose you will only find it out in the spring... Please keep us current; I'm very curious about how it will be the next few months with your battery.

 

[JejuSoul]

...There have been reports of failing battery packs also in Norway. As some owners has had their cars 5 years (first cars were delivered autumn 2014) many owners has reached 100.000 km (appx 60.000 miles) or more. I don't know the percentage which have claimed replacement, (Norw. warranty: 70 % capacity after 150.000 km/7 years), but my impression from Norw. EV forums/Facebook groups is that a lot of owners of the cars which have passed 100.000 km are experiencing degradation problems. Some have had their battery packs replaced after waiting up to 6 months on a new pack...

Thanks for posting Zattaxu. This is the first battery replacement story from Norway I have seen.
I have just read your post on elbilforum.no - Mistet kapasitet på fremdriftsbatteri - erfaringer?

I still think that as a percentage the failure rate in Norway will be much lower than elsewhere. At present almost 42% of all Soul EVs ever produced are in Norway. Clearly some of those cars are now failing. But I assume many are not.
I base this assumption on the N issan L eaf, which has a high failure rate in the USA and a low failure rate in Norway.
Am hoping the Soul EV doesn't turn out to be worse than the L eaf.
If it is, then it means we have been looking in the wrong direction 'high temperatures' as the cause of most battery failures. Instead it may be 'battery stress' caused by long and fast journeys that are the primary cause.

I have been tracking the number of Soul EVs in Norway for quite a few years now because of the bogus news articles that came out about Kia doing an 'emission scam' and reselling cars from Germany into Norway.

Here is a chart that shows the total number of Kia Soul EVs in Norway broken down into those directly imported, and those 'sold' in another European country and then shipped into Norway a few days later. Here shown as imports.



The 'emission scam' articles can now easily be debunked if you know that now Norway is included in the EU emissions zone. The simple reason for importing cars is that dealers made money doing it.

 

[Zattaxu]

I still think that as a percentage the failure rate in Norway will be much lower than elsewhere. At present almost 42% of all Soul EVs ever produced are in Norway. Clearly some of those cars are now failing. But I assume many are not.
I base this assumption on the N issan L eaf, which has a high failure rate in the USA and a low failure rate in Norway.
Am hoping the Soul EV doesn't turn out to be worse than the L eaf.
If it is, then it means we have been looking in the wrong direction 'high temperatures' as the cause of most battery failures. Instead it may be 'battery stress' caused by long and fast journeys that are the primary cause.

So far I have read about appx 10 stories of failing battery packs in Norway (but remember that not everyone that experience battery failure write a post about it...). I think you are right in assuming that temperature is the single factor affwcting the battery pack, but it seems like long and fast journies are relevant as well, even in colder climate.

 

[Omar]

Also here in Jordan it is clear!. The Soul EV's here are mostly imported from the US, few are from South Korea. Most of the ones that are standing for sale now, specially 2015 & 2016 models, have degraded batteries. They have a range similar to mine (around 82 miles GOM reading at 100%) or less!.
My car battery's SOH has rebounded to 65.4%, it was 64.5% a month ago.
The local Kia does not accept the warranty claims, as they do not sell electric cars in the region. However, there are several shops that fix degraded batteries or replace them. You can see many types of fixes!

1. Replacing the bad cells. I checked with one shop in order to replace 4 bad performing cells in my car, the cost will be 400$ for the cells and labor!. But Kia Soul cells are somewhat rare. They are normally dismantled from a wrecked car, or a good performing cells out of replaced batteries.
2. Installing a Nissan Leaf battery into the Kia Soul, knowing that Nissan Leaf is very common here, its batteries and cells are easily available in the local market, and they are cheaper. This fix costs little higher than 2,000$
3. Some cars get an assembled battery, composed of a certain number of cells of other car batteries, you can see some Kia Souls with 38 kWh batteries !!, most likely these cells are either Bolt EV cells or Nissan Leaf cells! This might cost more than 3,500$

Some mechanics are in fact electrical engineers, they even install a cooling system and connect it to the car BMS!

 

[Oinq]

2. Installing a Nissan Leaf battery into the Kia Soul, knowing that Nissan Leaf is very common here, its batteries and cells are easily available in the local market, and they are cheaper. This fix costs little higher than 2,000$
3. Some cars get an assembled battery, composed of a certain number of cells of other car batteries, you can see some Kia Souls with 38 kWh batteries !!, most likely these cells are either Bolt EV cells or Nissan Leaf cells! This might cost more than 3,500$

Some mechanics are in fact electrical engineers, they even install a cooling system and connect it to the car BMS!

Impressive!

 

[Zattaxu]

But now, the winter is coming, I suppose you will only find it out in the spring... Please keep us current; I'm very curious about how it will be the next few months with your battery.

I have read some more posts on the Norwegian facebook forum for Kia Soul EV owners complaining about battery degradation and/or owners that have had their batteries replaced. One of the owners claim that his 27 kWh battery was replaced by a 30 kWh battery. According to him the Kia dealer called him after he had picked up the car, saying that he had to come back for a software update (for the GOM to work properly).

 

[JejuSoul]

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One of the owners claim that his 27 kWh battery was replaced by a 30 kWh battery. According to him the Kia dealer called him after he had picked up the car, saying that he had to come back for a software update (for the GOM to work properly).

Interesting find. Thanks for posting. There is a thread discussing the replacement batteries here - 2016 Soul EV+ Battery Replacement - Re-manufactured?
We have no proof that anyone has actually received an upgraded battery, despite lots of anecdotes. Kia is not saying anything
I'm still waiting for my battery to be replaced. Am hoping it's true.

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Saw this comment on the facebook forum

My SOH started to deteriorate around 166,000 km when it "dropped of a cliff", dropping from the mid 80% range to 60% or so almost over night.

The warranty limit is 160,000km. To see a sudden cliff in the deterioration just after warranty expires must be really annoying.

 

[oldpueblo]

I just purchased a 2016 Kia Soul EV with 43k miles, and it had the battery replaced by Kia just before I bought it (I called the Kia Dealership it was serviced at on the CarFax to verify it). I'm not fully up to speed on everything regarding the battery, but I can run Soul EV Spy and report back anything if that helps anyone.

 

[Omar]

Updating the status of my battery, now SOH has dropped to 62%, with the temperature drop in December its range is down to 115 Km. (It was like 145 km last winter). While my daily commute is sometimes 78 km while other times 98 km, So I decided to replace 4 - 5 cells, I called one famous mechanic here, it will cost me 400$.
He will use the cells from a used car battery. We agreed that I will check the performance of the cells within 1 month after the replacement. He will do it during my work shift, hopefully.

But I do not know really how much improvement I would get!.