Battery at 50°C during DC charge

Discussion in 'Hyundai Kona Electric' started by Mathieu, Aug 31, 2020.

  1. Mathieu

    Mathieu New Member


    I recently made a long trip with 3 stops to charge. During the second charge, I noticed the battery temperature peaked at 50°C and looking back at the logs captured with torque pro, it seems the charge power dropped from 50kW to 25kW when the battery reached 50°C (SoC was still in the 60s%).
    I am concerned the battery cooling system of my car is inoperative. Did anyone experience something similar? What is supposed to be the temperature range of the battery during DC fast charging? Any idea on how to test if the cooling system is functional?

  2. There is a massive thread about this issue over on SpeakEV.
    ericy and GeorgeS like this.
  3. I would have to check my logs, I just did a 574 miles drive with 4 quick charges. The battery temp I believe went to approximately 45°C during the charge and then went back down while driving.

    My drive was from Las Vegas to Los Angeles and back. Outside temperature was between 35 and 40°C.

    From my everyday experience, if you leave the car in the sun at 40°C, the battery will great up to about the same temperature over the course of several hours. Doing the remote start and AC will cool the battery too, otherwise just starting to drive will lower the temp if the cooling works. It takes about 20 minutes to get the battery temp from 40°C down to 35°C.
  4. Mathieu

    Mathieu New Member

    Here is a plot of the temperature profiles while charging. The inlet temperature doesn't drop at all! charge_profile.PNG
  5. I just checked and the battery temp went up from 35 when I arrived at the charger to 42°C at the end of the charge on my last of four fast charges.
  6. Mathieu

    Mathieu New Member

    An update on my issue: the BMS software update fixed the problem.
    It's crazy to realize that my car was delivered with a version of the BMS software that let the battery go up to 50°C (in mild weather too), and not activate the cooling system!
    electriceddy likes this.
  7. Just to clarify; your Kona EV is a 2019 model and the BMS software update that solved the overheating of the pack while DC charging issue was the Service Campaign 960 application ... is that correct?
  8. Mathieu

    Mathieu New Member

    Yes that is correct.
  9. hobbit

    hobbit Active Member

    I have *finally* slogged through the entire Speakev thread to the end. What an absolute
    nightmare. I have no confidence that dealer techs in the US would handle this any
    better, given what we've seen on other issues/stories to date.

    What I would ideally hope for is that someday there could be a retrofit reflash to
    the CCS charge controller to support Plug&Charge and that would go hand in hand
    with revised BMS updates to suppport it, coupled with far better training of the
    people on the ground tasked to handle it, but that's probably too much to hope for.

    It was interesting that Hyundai itself chimed into the conversation, unless those
    were just fake sock-puppet posts from someone unaffiliated just to do some
    sort of weird backhanded trolling. It was very detached and whoever it was didn't
    really *engage* with that community and continue a real conversation. If it was
    really Hyundai, it provided yet another example of the same arms-length attitude
    they seem to have toward their customers. Is that a cultural thing? It seems so
    incredibly unproductive in the long run.

    And it wasn't even halfway through the 30-something pages of thread that the true
    original problem was brought to light -- a bum coolant pump, possibly due to the
    same internal leakage problem noted in the other recent TSBs. It strikes me that
    this should be mostly detectible by simply feeling temperature of various parts that
    are reachable from under-hood during charging -- hoses in and out of the pack, the
    chiller module, and the pumps and radiator.

    What a sad travesty all round.

  10. ericy

    ericy Active Member

    I am slogging through the thread myself - now I am wondering how common these problems are. It seems like the car should have thrown a fault with high battery inlet temperatures at a time when the chiller is expected to be running. It isn't clear that they ever figured out the problem in the OPs car - they replaced some parts, didn't work, and then he went silent. Sounds like he was getting a new car, but he is trying to stay on the good side with Hyundai and staying quiet.

    I am looking through old SoulSpyData logs. I have a log from 06/03 - I see temperatures of around 120F, with a battery inlet temperature of 116F. At the time, I had no context - I was sort of watching the temperature, and saw it sort max out around this temperature, but back then I had no reason to believe that there was a problem. But back then, the battery cell voltages were all the same, but a battery inlet temperature of 116F seems way out of line. If I could go back in time, I would fiddle with climate control settings in the car and see if if by turning it on/off I could get the inlet temperature to come down. I will post some screengrabs on the other thread...
    electriceddy likes this.
  11. Mathieu

    Mathieu New Member

    I tried every possible setting of the climate control and combination with the state of the car and nothing got the chiller started. I even tried to unplug the temperature and and pressure sensor at the output of the chiller to see if that would trick the software in triggering it, but no luck either.

    Since on my car the problem was purely software related, I expect a good number of people had the same issue. And it’s not obvious really, except for the fact that the BMS slashes the DC charge current when the batter gets to 50C.
  12. ericy

    ericy Active Member

    You could be right. To me it seems that the car ought to throw a fault if it expects chilled coolant at the battery inlet and it isn't getting it. On my car, the AC was working, so the compressor was doing its job - I expect that the same was true in your case.

    I am sufficiently annoyed that I am starting to research lemon laws just to see what I can find. It has literally been in the shop for 30 continuous days, and that by itself is of the things that makes it eligible in most states. If nothing else, I could mention it to Hyundai to try and light a fire under them. It is really just waiting for parts but with no ETA given. It could be tomorrow, it could be 6 weeks from now.
  13. BlueKonaEV

    BlueKonaEV Well-Known Member

    Your battery cooling is definitely faulty.. I have some information on this issue that I can't publicly post. I will send you a PM with the information.. I would definitely bring the car to Hyundai. Attached is a chart how battery cooling should work.. The chillers and water pump should come on at 98.6F/37 Celsius and stay on until the battery max temperature drops below about 35 C..
    Here is how cooling should work. My example is in the steamy hot Florida climate... The hottest temperature I have ever seen was 105.9F/41 C.
    On most hot summer days, it never goes above 39 degrees... My chart is in degrees Fahrenheit.. Peak temperature was around 100 F/ 37C Celsius.
  14. Mathieu

    Mathieu New Member

    Thanks for sharing, after the BMS software this is now the behaviour I am observing during fast charge, with the inlet temperature suddenly dropping when the chiller is activated.
    Before the update, the inlet temperature was just going up as the battery temperature was going up.
    electriceddy likes this.
  15. BlueKonaEV

    BlueKonaEV Well-Known Member

    Oh, I just replied to your message before reading this.. If it cools now, no reason to bring it to Hyundai.. Just keep an eye on it..
  16. hobbit

    hobbit Active Member

    What could be so proprietary about this? Secrecy is not productive here, unless it
    involves personal info.


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