RECALL) KONA EV - BMS UPDATE and 20% Reduce cell capacity

So assuming a 1kw/hr charge rate after 80% SOC it could take another 12-13 hours to reach a 100% SOC. So on highway trips they have essentially functionally limited you to a 51Kw/h battery pack. Not a cool penalty considering Kona's built after March 2020 are somehow magically exempt. If this is Hyundai's best shot at a fix I am afraid I will take a hard pass on the recall.

 

Is this only for DC charging? I've only DC charged once, and it was mostly for the sake of testing.
Also, I'm a little surprised people are charging to >80% during a road trip. Doesn't the charging speed fall off pretty fast even now? (The same is true for Teslas -- the only time I did a road trip in a Tesla I couldn't bring myself to wait around for 100%).

If it affects all charging, I'm wondering how it affects regenerative braking (which could easily be an order of magnitude more than AC charging).

 

Regardless of AC or DC charge sources this a wet noodle for me. Unfortunately for me my highway options for charging are very limited in middle Canada( there are literally currently only 3 DC chargers servicing one major 500 km highway in Manitoba )and when you factor in the 30-40% loss of range due to cold winter weather I sometimes need to get a charge past 80% so that I have any chance of getting home from a distant jobsite.

Sent from my SM-G955W using Inside EVs mobile app

 

Can you post the full url of the site you have done the screenshot of? I know some people that could help me do a better translation potentially.

 

Based on how, I *THINK* this reads, it sounds like charging speeds are normal up to 80%, then drops while it checks the battery and such check may take 10-30 minutes, then resumes back at normal speeds for the rest of the charging, but I really need the original link to better confirm.

This would mean a max of an extra 30 minutes, which I don't like at all, but better than 12+ hours extra. I could live with the 30 minutes extra, the 12+ hours extra, I would be pushing for a different solution. I could also accept this on a temporary basis while I wait for a new battery that doesn't have this restriction at all.

 

All I've seen are two photos of the dash console; one at ~62% and the other at ~92%, both showing 1KW charging rates. That is nowhere near enough information to draw any conclusions yet... stay calm at least until there's enough reports to see a pattern!

 

If it is 1 kW charging at 62%, then that would indicate and issue with the charging station to me. And I have had my charging rate drop to 1kW at about 98% and other times remain at 7+ kw all the way to 100%. So as you, say we can't tell until there is either official confirmation from Hyundai or we see a pattern.

 

I am not particularly distressed about this as I feel I still can exercise my option of not participating in the recall if it does not makes sense to me. Sadly though the early anecdotal reports from South Korea are starting to confirm my fear that Hyundai is going to select the cheapest option( to themselves) to fix this problem. I am put off with the idea that a suboptimal software patch is the solution (who's burden of actual cost/inconvenience will fall on the owners of the vehicles) to what is suggested by Korean government as a hardware manufacturing defect.

 

I could see this being issued as a temporary fix until they can have enough batteries to start doing swaps, but I don't think it would be accepted as a long term solution.

 

Is that the first time after the update you reach the 80% threshold or every single time ? That text does not mention 30 minutes, it just mentions "there are areas where charging does not proceed during monitoring for 10 minutes after 80%".

Exact google translate is

"Battery check logic for 10 minutes at 80% charge added
Due to this, there are areas where charging does not proceed during Monitor 1 (10 minutes).
In test 3 and normal, charging is done at normal speed.
There is a part where the charging time has increased due to the addition of the test logic, but there is no part that limits the available battery capacity§
次 次へ In the event of an abnormality with the test, the warning light will be stopped and the charging will stop / start S
We are once again sorry for the part of the clothes that we did not get enough information in advance as we implemented emergency measures 5
In the near future, we will prepare a Q&A for the number of recall measures and provide reliable guidance.
Thank you for using the website 1:1 inquiry"

 

I am wondering if they are balancing of the pack when you hit 80%, and once this is complete then the charging resumes.

 

80% sounds like a pretty arbitrary point too (and does not seem that realistic given people have seen that "1kw charging" at other battery SOCs). I guess we'll have more data as time passes.

 

I know. I hate that we have to guess, and the poor translations from Korean don't make it much easier.

 

I wonder if they reduce charging power whenever the cells get too far apart in voltage, and balance multiple times on the way up rather than waiting until near/at the end. I can imagine, hypothetically, that since they're so close to the limit they might not want to risk letting the cells drift too far apart under any circumstances.

 

Yup, I assume by the time December comes we'll have a bit more rigorous data and/or a better software update / battery change for affected cars .

 

Some things never change.

Without getting bogged down in the minutia, save it to say I had a new 2007 Honda Civic Hybrid that had (a fleet wide) software update to cover a sudden battery degradation issue.

The update simply dumbed down the amount of assist the battery offered...and predictably the efficiency dropped.

I ended up selling that car prior to it being 24 months old...

 

I think that's exactly right. And, the reason behind the slowness indicated may be due to the capacity of the cell monitoring hardware to dissipate power to bring down the voltage of the higher cells in the case where there is an actionable variation. This could be a limitation that software cannot get around, e.g. size of resistors if passive balancing is used. When the charge rate is shown as 1kW, it's no-doubt just keeping the car's systems alive without drawing from the traction battery. The time required for balancing might be long at first but could improve as cells variations are tightened up.
I think many of us here would see a cell voltage variation of no more than one increment, that being 0.02 V, and may not see extended times as that's about as good as balancing can get.

Here's the translated text from the SK forum post that kenny kim posted on SpeakEV, in case it hasn't been quoted here. There are so many posts on the various forums I can barely keep track of them.

I'm a little surprised they didn't take the opportunity to reduce the peak voltage just a tiny bit. it could be either due to hardware limitations or to avoid getting sued for reduced product performance.

 

This did seem to be a flaw in the previous BMS update - once the pack got out of balance, you could no longer charge, and thus there was no way to re-balance. The end result is that your car ends up in the shop, and nobody knows how to correct it.

And for that matter, the only known way to re-balance in the past was to charge to 100%, which is probably a little unwise if the pack is already out of balance.

The other side of this is that you might have a cell in the pack that is going bad, and rebalancing isn't going to help you. So how do you tell? That's the dilemma.

 

Likely a version of this. If some cells are nearing max voltage the BMS can only hold them down to some extent. Ultimately charge current would need to be reduced so the BMS can keep them from an over voltage condition.


Sent from my iPhone using Tapatalk

 

I think that situation will remain and replacing the entire pack is still the only practical option. Checking balance occasionally using TP or SoulEVspy could give an early warning. I've had one that is always slightly down (~0.02) so I'm checking it frequently.

I would assume if a cell voltage is well below the average the "check" light is triggered.

I can imagine that an example that has been DC charged frequently misses out on cell balancing and could suffer damage when eventually charged to 100%. But that doesn't explain the several examples that apparently failed when nearly new.

I don't see how it's possible to measure cell voltages while charging. Charging must stop entirely and cells allowed to settle.