Replacing the single cells in the battery pack?

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This graphic shows about 60 cells, first 30 and 30 last. We can see that it’s no 1 red only drastically week in comparison with others.
Better than having 5 or 10 spread all over and than I’ll need to open every pack and get them out and put “new” ones.
My OBD2 app can’t show graphs for all 96 at the same time.
Hello. First let me say that I admire your willingness to try to solve your problem yourself.

btw, I can see the original photo you posted, by I'm using Safari and am also a iCloud user so maybe that has something to do with it.

In my layman's opinion, I believe that only #4 or #5 of your options above may work.

#5 would be the "safest" as in most likely to work, but you'll need to find a used battery pack at a wrecker (not that hard I looked for a gearbox and some other parts using the online wrecker network in the past). Shipping something that large and heavy will be very problematic I suspect, so if you live near an area where they might have one it would be more practical to pick it up in person.

#4 may also work, so long as the BMS doesn't somehow detect something unexpected is happening, the new higher capacity cell will just never get fully charged itself since the lower capacity cells will reach max voltage sooner. The question though is just how charged will the larger cell actually get before the BMS cuts off charging?

If the cost isn't too much, I'd be inclined to try #4 first just because it is much simpler logistically.

You can also purchase a PDF of the service manual for your car which will provide step by step instructions on how to remove the battery pack, etc.

You need to follow every safety precaution, there are very dangerous voltages and current involved when dealing with opening the battery pack.
ksoul2084 said:
I admire your willingness to try to solve your problem yourself.
In my layman's opinion, I believe that only #4 or #5 of your options above may work.
You need to follow every safety precaution, there are very dangerous voltages and current involved when dealing with opening the battery pack.
I agree with ksoul on all this.

If you look at the module temperatures of a failing battery pack you will see that the entire module that contains the bad cell gets much hotter than all the other modules. This module is getting much more stressed than the others. I think this will continue to be a problem if you just disconnect the bad cell, which is why I believe that only #4 or #5 of your options above may work.
The reason Tesla can do it is because they have 1000's of small cells.It is much less of an issue if one goes bad. I think Tesla made the right decision from the start in the way they design battery packs. But I hate the way so many technology companies nowadays are making it impossible to fix something yourself.


Here's a video showing DIY LED lightbulb repair. In this case the simple solution of bypassing the dead cell does work.
I think this is a brilliant video that should be more widely shared.

Thanks for your feedbacks.
Great tip for getting the service manual, found one for free. After looking into it, I’m one step closer to solving my problem. Yes, I’ve seen few good videos about taking apart the battery but with the service manual it’s much easier and safer. Lots of details and no mistake what is what until you get to the battery pack. From there the videos will kick in, they show how to get to individual cells.
Will look closer into the temperature difference between first pack with no 1 bad cell and others. For now I was monitoring only behavior of individual cells during my trips.
I’m not sure how to check does my cooling system work, does fan goes on only in summer 🤣. It’s winter and I live in Switzerland 🇨🇭. When I looked into fan parameters with OBD, graphic was showing only flat line. I’ll make sure to monitor the fan and the temperatures on my next trip, specially when turtle mode comes back.
I’ll definitely get some cells, new or old, before I get ready. It will save me lots of time to have all options available on the day. And then I’ll decide what to try first 🤞.
I’ll put some more graphs here, but what else should I look for, OBD gives you lots of options to monitor?
Jejusoul, thanks for the advice about the temperatures.
I’ve monitored all 8 packs and no 1 (with bad cell) is heating more than others.
Being cold in Switzerland, but not extremely for now, it’s not possible to see how hot packs will be in the summer.

First photo, morning trip to work, 50km, outside 6 degrees Celsius when started, 10 degrees on arrival. “Down hill” journey from 850m altitude to 600m altitude. Consumed 55% from full battery.

Second photo, on the way back, outside 10 degrees. Consumed 80% battery from full, I charge my car at work level 2, at home level 1.

Red graphic it’s pack 1, middle brownish graphic is pack 8 with cell 96 which is slightly weaker than others but still much better than no 1 and bottom graphic is group from 2-7 pack.

I guess presently I could make 75/80 km with the 100% battery which is still ok for my needs.

Little addition on my idea 2:

Idea 2:
Physically open battery pack, disconnect no 1 from the system. Then connect the second cell directly with new cable directly to beginning off the pack. Problem is that the sensor attached to the cell no 1 will show error and car will not run at all.
***charge the car to full before disconnecting the battery, cell no 1 will be 4.15V and others around 3.95v. After accessing the cell no 1, find the way to disconnect it from the circuit but keep BMS sensor for voltage. Cell no 2 connect directly to end off the circuit where no 1 was connected. With good size conductor/cable with smaller resistance than what the whole circuit has to prevent from becoming the fuse and breaking the circuit.
BMS might see cell no 1 stable with slowly receding capacity due to self discharge and will carry on monitoring others. This might allow other cells to charge to the on next charge and give more juice and longer distance.

Thanks in advance for your inputs.
Hello. Sem iz Slovenije, lastnik soul 2015.garancija potekla Soh 44%.Menjal 12 celic. Sedaj Soh 60%.Pomoč sem dobil pri sosedih na Hrvaškem. EV CLINIC ima rabljene celice, preverjene za cca 60eur/kom+poštnina.
This last message translates to
Hello. I am from Slovenia, owner soul 2015.warranty expired SOH 44%. Replaced 12 cells. Now SOH 60%. I got help from my neighbours in Croatia. EV CLINIC has used cells checked for approx. 60eur/com+postage.
Presumably this means he got 12 old cells for 60 Euro and successfully replaced them into the pack.
Please post again with more details I would like to hear more about this.

Possible he is talking about this repair by the EV Clinic in Zagreb. : - Kia Soul – SK Innovative degradation fail


Kia SOUL EV – Our favorite EV is stuck in the throes of extreme degradation and just when you think you need a new battery, our EVC lab becomes your salvation because we repair it on component level by changing cells. The vehicle that was previously driven in hot Spain left a mark on the battery cells, which apparently damaged almost half of the battery system due to poor cooling and high operating temperatures. The story here is deeper than the degradation of the battery itself, because there is also the “degradation” of the KMAG user experience, which has become extremely unfriendly in terms of conditions and fulfillment of warranty requirements. Here, the warranty on the battery, which is still active, was completely unjustified declined, because the service book (wtf is service book for EV) is missing. The already familiar story with KMAG, where we witnessed several times the rejection of the warranty for completely unfounded reasons, for example by asking for the invoice of some first service and similar “strange” stories where they tied the general warranty to the warranty of the drive system which is extremely stupid and invented just to be the reason to reject warranty. But where KMAG “bendovers you”, EV Clinic try to save you. With a short run-in test, we isolated the worst cells of the “first layer refurbish”, replaced them with LGX cells from the Hyundai Ioniq, given to us by our colleague Peter from Slovenia and a colleague from France with almost new SK Innovative cells. We had enough to repair half a battery pack. We changed all the upper “overheated” cells and made the first test, which under the new “second layer refurbish” showed an additional 8 groups in bad condition. The third layer and the test showed that the complete group 1-14 under the passenger side is extremely bad and we decided to change the complete block by changing all cells. Through the tests, we had from the initial 50 km of range, to the 85, 105 and then at the last 118 km of range, which brought the condition of the battery to a usable state for use in the next 1-2 years, where we can only hope that some aftermarket solution for cells with approximately the same dimensions will come out. Because dimension of cells about 10.5 mm is the decisive factor.
In the second layer, we had only 19 kWh of the declared 28 kWh on measurement, which is about 65% SOH or 35% Degradation. In the last “layered refurbish”, we measured a usable 22kWh, which is about 75% SOH or 25% degradation, which is a big change in any usable case. We will remove the vehicle from the list of recommendations and suggest Kia NIRO EV, which has Active thermal control with antifreeze and coolant plate with same cells.
Hvala Bina, čuo sam za njih i izmenio 2/3 mejla ali mi nije palo na pamet da hoće i da prodaju ćelije jer im trebaju za popravke. Cena je interesantna jer mi treba samo 2 za pocetak i stići će brze nego iz Kine 🤣. Poslaću im mejl da vidim da li će mi prodati. Ja sam poreklom iz Srbije.

JejuSoul, being born in Serbia and “understanding “ little bit of Slovenian I can only add to your translation…
60 € is cost off one single cell.
This is great news for me because I need only 2 and delivery cost will not be to steep Croatia to Switzerland. Buying from China will take some time and money, not being original, for the first repair I’ll try with the second hand ones.
Tako je JejuSoul.Cena je za kom.Celice so spojene dvojno ena nad drugo Zgornje imajo drugačne priključne terminale, kot notranje. Poglejte video na strani EV CLINIC .Za eno celico potrebujete 2 celici.Po menjavi in balansiranje se bodo pojavile druge slabe celice.Predlagam da kupite app. kia spy in ustrezen obd-KONNWEI,kateri bo v veliko pomoč pri odčitavanje podatkov.
Unfortunately Croatian EV Clinic is not able to sell me any cells, they desperately need them for their clients. They’ve assured me that my car has more bad cells than showing on my graphics. I guess I need to prove them wrong or eat my 🎩.
I’ll try to buy some similar from China and see.
But I still believe that I can do something along my previous ideas.
Ste pogledali na njihovo original spletno stran Zgoraj desno kliknem menu, trgovina kia mi pokaže 61 kom. Cena 55eur z ddv+ poštnina. Izbereš količino, vpišeš podatke, nakažeš denar in v cca 1 tednu dobiš... Kar zadeva število okvarjenih celic, ima ev clinic prav!! Trenutno vam BMS zaznava najslabše celice in prilagaja polnjene-praznjenje tem celicam. Zaradi varnosti... Res se bo po menjavi okvarjenih celic domet in kapaciteta polnjenja povečala.A ne na 100% Po večini so okvarjene ali slabe vse zgornje celice.Če pogledate video na njihovi strani vam bo bolj jasno.Kot napisano meni je v začetku app. Soul spy pokazal zelo slabo 1 in 14 celica paket 1 in 83in96 celico paket8 - SOH 44% Po menjavi SOH 55%.Po nekaj ciklih in balansiranju se pokažejo druge slabe CELICE, ki omejujejo BMS.Pri meni celica 73 in82 v 7paketu. Po menjavi 6x2celici je Soh 62%-100km....Meni zadostuje... .Kot omenja v videu mojster ev clinice. Za učinkovito popravilo je potrebna menjava test, manjkava.... meritve upornost celic...
Hvali ti puno Bina,
Naručio sam preko tvog linka direktno, ja sam preko maila verovatno menjao poruke sa nekim ko radi u garaži za popravke…
Dugujem ti piće ako ikad skokneš do Švice, okolina Ženevskog jezera 😀
kojairvs - great news that you have found somewhere to get a few cells quickly. Good luck with your replacement. Although I too believe you will be eating your hat. I think you will need at least an entire module worth of cells.

I've removed parts of this post where I mistakenly thought the label 37501-E4000 was for a different car.
It isn't. In the the Ukrainian YouTube video posted we see this sticker on the outside of the Soul EV battery case,


Nothing to celebrate yet 🙁
After I’ve got automated confirmation with payment details and amount, I’ve sent the payment.
This morning I’ve got mail saying that all orders are automatically canceled. When I inquired about refund they were not happy with me because it is hustle for them now to send money back. They should’ve canceled this site or block options to order online, how could I know?
Waiting to see what will they do.
Found another great video from Ukraine, part one but no second part on YouTube. Very detailed.
kojairvs me veseli, da sem lahko pomagal. 👍😄. Želim uspešno in varno popravilo baterije in objavo rezultata.To bo stalna praksa po poteku garancije, ker nove baterije so zelo drage cca 16tisoč eur😵😵.... Opozoril bi samo da bo potrebna prilagoditev priklopnik terminalov z preoblikovanjem ali ponovnim varjenjem. Žal je malo predaleč a vseeno,, na zdravje,, 🍻. VESELE PRAZNIKE
Se strinjam z vami Obžalujem. Jaz sem naročil v oktobru in še ni bilo težav.Verjetno so povprašrvanja velika, ker je zelo znan serviser EV bivši jugi in EU. Upam da ugodno rešite zaplet
Ok, after not being able to get second hand cells from Croatia or from somewhere else, I went to Alibaba and shopped around.
I’ve managed to order 4 cells from one company and I’m waiting to be delivered.
Price per cell is decent and delivery is what it is. If this works and they are accepted by my car’s BMS I will be able to buy more cells in the bigger batch.

They are 40Ah not 37.5Ah but beggars can’t be choosers.
I think it’s probably length of the so called “ears”. +/- connectors.
Other measurements should fit into place of the old ones.