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Discussion Starter #1
Just spotted this as a follow up to reports last year and earlier this year about some Kona battery fires. @Hyundai Motor UK is this going to affect UK/European cars, or has the recent BMS update addressed the problem?


John.
 

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Thanks John.
At the moment its not a very definite report about this issue - see extract below:
(upper case = my emphasis)

"POSSIBLE short circuit due to what MAY be faulty manufacturing of its high-voltage battery cells COULD pose a fire risk"
 

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Discussion Starter #3
Thanks @davesul ,

I did @ mention Hyundai UK to see if they have any comment to make - I'm not holding my breath, but it does look like all the fires have occured in cars that have not had the recent BMS update. You'll need to open this in Chrome and translate it!


John
 

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Even according to the news report, this is voluntary recall, so it seems a low risk?
 

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Discussion Starter #5
Translation of the relevant paragraph:-

First of all, Hyundai Motor Company is expected to encourage all customers to receive the program update service of the Battery Management System (BMS). Kona EV has sold a total of 33,1841 units in Korea by the end of September, and all vehicles that have been burned so far are known to belong to 30% of customers who have not received BMS updates. By simple calculation, it is estimated to be about 10,000. It seems that it has been determined that additional fires can be prevented with the BMS update.

John.
 

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Wicked problem. If the manufacturing problem that leads to a short circuit inside a cell happens in every millionth cell made, it's still dozens of cars that will burn. After the cell short-circuits and burns, there is nothing left of the cell to study to understand why it burned and what can be done to prevent it to happen again. I'm not really optimistic that the BMS update alone will prevent this. Maybe you can figure out approaching cell failure from voltage/internal resistance/temperature of the cell compared to others?
 

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I think it is interesting that it is just the Kona. The Kia E-Niro which afaik shares the same battery system does not have the problem. Thus my best guess it is NOT the battery system per se.
 

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The Kia E-Niro which afaik shares the same battery system
Originally, when they were launched, the Kona and Niro shared the same drive-train, or design of it but, their batteries were from different manufacturers. Kia got them from SK Innovation and Hyundai from Samsung SDI. That might have changed in the last year or so, but I'd doubt it.
 

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As a result of the investigation by the Korea Automobile Safety Research Institute, it was found that there is a possibility of an internal short circuit due to damage to the separator between the positive (+) and negative (-) plates due to defective manufacturing process.

This recall is a voluntary recall from Hyundai, and the way it will works is that after updating the battery management system (BMS), if there are any signs of battery abnormality such as excessive cell voltage deviation or rapid temperature change are found, the battery will be replaced immediately.

In addition, even if there is no abnormality, if an additional abnormal change is detected during the constant monitoring of the updated BMS, charging is stopped and the engine is not started, and a warning message is automatically delivered to the consume
Looks like what @mikeselectricstuff said, the new BMS is more strict at monitoring.
 

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Discussion Starter #12 (Edited)
A snippet of info I learned from a chat with the tech who came from Hyundia UK to fix my BMS update is that the new BMS software has a tighter spec on maximum cell voltage deviation ( and in one case this led to a customer having a battery replaced after the update).
@mikeselectricstuff ,

That sounds correct based on some information that came my way (I've redacted identifying info to protect my source). this is a reply from a Hyundai Korea engineer to an email enquiry. The reply was in Korean and has been translated, so looses a little bit of clarity, but bears out what you've been told, confirms that Aux Battery Saver+ gets removed, and I'm guessing that NOTE 2 below confirms that 4 cumulative REGISTERS get reset to zero (CCC CDC CEC CED) which gives weird GoM readings after the update.

John

[Purpose]

This upgrade changes the high voltage battery sensitive and frequently checks for cell voltage deviation and insulation resistance,
so that problems can be identified and taken early in the event of a hazardous situation.



[Changed Logic]
1. Proceed the upgrade, the cell deviation and insulation resistance measurements become sensitive.
1) Cell deviation)

- Before : Detect problems when voltage deviation is higher than 1V.
- After : higher than 100mV (Level 1) / higher than 150mV (Level 2)
2) Insulation Resistance)
- Before : Less than 300kΩ
- After : Less than 900kΩ (Level 1) / Less than 700 kΩ (Level 2)

2. The inspection cycle will be changed as shown below.
- Before :
Check the condition of the vehicle once 24 hours after starting off)
(At this time, check the condition of the 12V battery to support charging
from the high voltage battery if the SOC is insufficient)
- After : Monitor the vehicle condition for 2 hours in a row after starting off, then check the condition of the vehicle for 4 hours. (Total of 2.5 days)
* Check for 2 hours in a row for the first time only
* Check the condition of the vehicle once every 24 hours after 2.5 days.
* Check auxiliary battery SOC when monitoring the condition for supplementation.

* NOTE 1) As a result, the dark current can reach up to 300 mA even after starting off.
Based on the logic above, it will be lowered to 50 mA level after 2 hours.
* NOTE 2) In some cases, it is reported that the four controllers are discharged after updating them.
This may occur if the vehicle is parked in a short drive with a large number of auxiliary battery SOCs.
* NOTE 3) In some cases, you may be asked that the battery charge function button is disappeared in the cluster.
When vehicle monitoring starts, the 12V battery SOC is also checked at all the time.
then if insufficient, The auxiliary battery is charged. (The charge logic is always active.)
 

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Discussion Starter #14
What do they mean by "level 1" and "level 2"? Charging?? Or something else entirely?
I would speculate, reading the engineers reply together with the BMS TSB, that cars that have had the BMS update successfully applied have their HV battery monitored as follows:-

Cell Volt difference less than 0.1V Car operates as intended (Like a brand new car off the lot) and rapid charges as per the improved curves seen on 2020 model year cars.

Cell Volt difference more that 0.1V but less than 0.15V (Level 1) Car goes into a reduced rapid charge mode where the charge curves drop sharply at a lower percentage. If you're in this mode it is probably worth AC charging your battery to 100% in order to invoke the cell balancing routine which MAY correct the problem!

Cell Volt difference more than 0.15V (Level 2) Car won't charge and throws a warning message to get it to a dealer! The dealer would then arrange to replace the battery under warranty, assuming that it's still in warranty.

I've seen reports of cars that have had reduced charging curves after the BMS update, but the Cell Volt difference hasn't been included in the report. If anyone out there has this problem after the BMS update and has Torque Pro, it would be really helpful to know what the Cell Volt difference is on your car.

John
 

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I can say from personal experience that a cell voltage difference of 0.12V is sufficient to make it impossible to charge the car at all. When I attempted to charge the car, it immediately stopped and threw faults. I needed to get a tow truck to take the car to the dealership the day after my BMS update. That was on August 15th. I still do not have the car back - a replacement battery is needed, but it is back-ordered and they are unable to provide any estimate as to when the replacement will arrive.

I would add that it isn't clear that they properly applied the BMS update the 1st time. The 2nd dealer re-applied the update - after this, they were able to charge somewhat, but the car was still throwing faults during charging. That's when they concluded at a replacement battery was required.

The level1/level2 described above may well be the intended behavior if the update is applied correctly. The dealer never attempted to charge to 100% to balance the batteries - I believe there were too many faults.
 

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When our car played up post BMS update, part of the fix along with re applying the update was to run to 0 and charge to 100%. But, looking at my cell data there has never been more than .02v difference in cell voltage, prior or post update and then eventual fix.

Therefore they are possibly looking at multiple problems, failed updates, partial updates that then bleat about cell deviations, proper updates highlighting cell deviations and insulation issues, the list goes on. All made so much harder to diagnose due to the partial updates and subsequent failures. It would have been far more black and white if the updates had worked properly, then the dodgy batteries would have been flagged correctly, although actually their pre update procedures should have flagged the dodgy batteries, at least from an insulation issue perspective.
 

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It seems like it is not all bad news....
 
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It seems like it is not all bad news....
Quite, whilst the media will pounce on EV’s catching fire, and it’s not a trivial issue, it certainly isn’t as profound as they are bound to make it sound. Hyundai could have quietly sorted this in the background, but their dealerships appear to have made a small problem into something much bigger by not completing (for whatever the reasons) the updates correctly. If there is an area they desperately need to address its their dealer tech training IMO. With all that said, our dealership managed eventually with the help on Hyundai Europe to resolve our post update problems, so I don’t see why others can’t too.
 

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Quite, whilst the media will pounce on EV’s catching fire, and it’s not a trivial issue, it certainly isn’t as profound as they are bound to make it sound. Hyundai could have quietly sorted this in the background, but their dealerships appear to have made a small problem into something much bigger by not completing (for whatever the reasons) the updates correctly. If there is an area they desperately need to address its their dealer tech training IMO. With all that said, our dealership managed eventually with the help on Hyundai Europe to resolve our post update problems, so I don’t see why others can’t too.
TBH, my internal conspiracist is screaming: possible fire 🔥🚒👨‍🚒🧯 and only voluntary recall! That is a considerable discrepancy, which to me makes it clear: that there is no fire hazard, but due to the publicity of the couple of fires in cars, Hyundai is making a big deal of their "recall" in a huge public campaign. It has been proven on a number of occasions that OEMs use the "recall' system as publicity stunts.
 

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Quite, whilst the media will pounce on EV’s catching fire, and it’s not a trivial issue, it certainly isn’t as profound as they are bound to make it sound. Hyundai could have quietly sorted this in the background, but their dealerships appear to have made a small problem into something much bigger by not completing (for whatever the reasons) the updates correctly. If there is an area they desperately need to address its their dealer tech training IMO. With all that said, our dealership managed eventually with the help on Hyundai Europe to resolve our post update problems, so I don’t see why others can’t too.
I see this as something Hyundai could have better dealt with by making the upgrade process idiot-proof.

From where I sit, the second problem is that they apparently have no inventory of replacement batteries (at least not where I am). They should have anticipated that there would be a need for some number of the things when they first started to push this out.
 
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