2015 Soul EV: My Battery Replacement Story

[tizjep]

I bought a 2015 Kia Soul EV from Carvana last month. It was showing about 56 miles when fully charged. It took about a month to get the logistic setup for transporting it to the nearest certified EV Kia service center (Schamburg, IL). I am scheduled for diagnostics next week... I am hoping that all goes well...

5/21/2020
It has been at the dealership since 5/14/2020. They had a tech look at it and have been waiting for diagnostics from KIA since then... They said that the initial diagnostic showed that my battery has low voltage.

5/23/2020
The dealer called today and told me that my high voltage battery was faulty. They have ordered a replacement and expect to have it installed by the end of next week.

 

[Sparky2]

That's great you got yours. I took my 2015 into Garden Grove Kia and they told me that the SOH was 92%. Now keep in mind the GOM says 60Miles at 100% uh... What is wrong with this picture? I submitted a complaint to Kia and they told me there was nothing they could do, they had to go off what the dealership said. So I did a test or two myself. Just a simple little, "run it around the battery charger" until the % just changed from 5 to 4% that should be about 4% charge. I DC fast charged it to 94% using 16.9KWh - so (correct if wrong) (94%-4%)=90% so with the original 27KWh capacity that should yield a SOH of (27KWh x 90%)/16.9KWh = 69.54% which is a far cry from 92% and just into warranty territory. What can I do since they seem to be denying reality?

 

[IanL]

Actually, you have written the formula incorrectly, It should be Measured kWh/(27x90%), which is what you actually did to get the 69.54% SOH.

However, the charger's measurement of kWh includes the power wasted as heat during the charging process. If 1 kWh was waste heat, the SOH would have been 65.43%

Try this: Zeroise the performance meter (the one next to the speedo which states m/kWh), note the mileage, and then drive back down to 4% and see how many miles you have covered for that 90% usage (call that M). Note the m/kWh reading (call that x) and work out how many kWh the car thinks you used. i.e. M/x. Use that to estimate SOH.

Alternatively, go to another KIA dealer, and get them to measure SOH without telling them that you have already had a figure from Garden Grove.

 

[Kish]

It's a particularly hot weekend here in SoCal, with temps above 120F (49C):

I decided to check the battery data since I was curious, and also it's been a while since the last check.
Update on my car after exactly 2 years and 6 months and 15.3k miles later:

e

SOH is down to 101%.. The min/max deterioration values moved around. Other than that, there's not much to report.
Due to COVID, I haven't been using my Soul EV much at all. That's why there's only 2.3k mile difference between my last reporting 10 months ago.

 

[Kish]

Update on my vehicle exactly 3 years and 18k miles later:

SoH is down to 97.9%. Min cell deterioration is 9.3% while max is 12.7%.

 

[JejuSoul]

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Hi Kish. As always thanks for posting the data.

Back in 2018 I commented

So there are a few possibilities about your new battery pack.

1. It is a brand new pack identical to the original. These had a total capacity of 30.5kWh, and a usable capacity of 27kWh.

2. It is a new pack that has been sitting in a warehouse for a year or more. It may have lost some capacity from the total but it still has a usable capacity of 27kWh. In a month or two there may be a sudden drop in the deterioration numbers as the BMS calibrates. You still have the 27kWh usable capacity and SOH=100%, but during the time it was stored it lost some capacity from the 10% buffer. This is often the case with new cars that have been sitting on dealer lots for a year or more.

3. It is a refurbished pack. They have found 'good' modules from broken batteries and put them back into a 'new' battery. I think this is unlikely because the labor cost involved is probably higher than just giving you a new battery.

4. It is a brand new pack based on the new 30kWh design that has been software limited to 27kWh. This would be the best for you. You still only have a usable capacity of 27kWh. But that will last a lot longer than usual because you will have a much larger buffer. I think this is currently less likely. But in future they will surely run out of the original packs, and they will have to do something like this.

I now think you got option 1. Your pack had a substantial buffer which had to be lost before any deterioration in usable capacity was lost. After three years you have now reached that point.

The original invoice you got shows the part number 37510-E4000. This is the code for an original new pack with 96 of the original E375 cells. (i.e. option 1)
Some other owners in the US have got re-manufactured packs. These have the code 37510-E4000-Reman (i.e. option 3)

Option 4 is what most replacements in Europe and South Korea are now getting. But it is not exactly what I guessed back then.
Instead I would rewrite the last option above as

4. It is a brand new pack based on the newer E400 cells which are used in the 30kWh design. The pack has 96 of the newer more energy dense cells (not 100 like the 30kWh cars). This pack shows the part number 37510-E4250

I have one of these new packs. I am reporting the details here :- Analysis of a replacement battery.

Please keep reporting it will be interesting to have more data on this pack.

 

[Kish]

Yes, I remember that post when you originally wrote it. I also think mine is option 1 or option 4.

Is it possible mine is option 4? My initial SoH % was 110% and now I'm down to 97.9%, which means I lost 12.1% over the course of 3 years. And this is with barely any miles added (only 18k after 3 years). Losing 12.1% after 3 years of barely using the car is also concerning, but that's another story. If it was option 1, shouldn't it have started at 100% SoH and decreased to 87.9% SoH now? I think it may be option 4, if it started at 110%, which means it came with a large buffer which it ate through.

The replacement pack that you got also say 37510-E4200 your picture (and not 37510-E4250), so isn't that also option 1?

 

[JejuSoul]

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Sorry. There was a typo in my comment that I just fixed.
You have the 37510-E4000 pack which is the same as the original. (It's on the repair paperwork you posted on page 1 of this thread.)
I have the 37510-E4200 pack which is the updated version.

Neither of us have a battery heater. These are numbered with a 50 at the end.

The newer E4200 pack performs much more like the 30kWh Soul EVs in terms of degradation. I think the battery chemistry was greatly improved to slow the rate of degradation that the 27kWh Soul EVs suffer. My car with a replacement battery has done 16,000 km in 16 months but has only suffered 0.1% degradation. ( Maybe the BMS algorithm has been changed however and this number is no longer meaningful.)

The value 110% SOH is used to show that the battery has 100% usable capacity plus a 10% buffer. Only 27kWh Soul EVs with the original battery can be at all certain that this is accurate. The Kia service will never show a value greater than 100%.
Everyone should ignore any value shown that is greater then 100%.