12 volt battery problem and nightmare Hyundai communications

Discussion in 'Hyundai Ioniq 5' started by CharlesBranch, Jul 16, 2022.

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  1. A few days ago I parked my Ioniq 5 with about 14% battery remaining. Today I decided to charge it up, but the charge door would not open--not even when I pulled the manual charge door opener. When I got in the car, nothing happened. No panel lights, no nothing. I thought I might have left the lights on, so I hooked up a 12 volt charger. I heard a few clicks and assumed it was charging, but several hours later, still nothing. I finally decided to try my old BeatIT jump starter. I heard several clicks, and voila, everything was suddenly working. This was weird, and it makes me wonder if something is wrong with the Ioniq 5 12 volt battery system. And it makes me a little nervous about being stranded in some remote location.

    While all this was going on I called the Hyundai roadside assistance number to see what they advised. That was a nightmare. All they said was they would have it towed to the nearest dealer (44 miles away). They would not take it to the dealer I bought it from (46 miles away). Both dealers said it would be several weeks to a month before they would even look at it. If I had not figured it out for myself, I guess I would have been without transportation for God knows how long. When I called Hyundai customer care, I got no help at all and was even cut off when I asked to speak with a supervisor.
    I find myself wishing I had kept my old Clarity. At least with the Clarity, I knew a reliable and cooperative dealer.
    ScubaSteve and electriceddy like this.
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  3. Addendum: I thought everything looked OK--until I got into the car for a trip. The Lane Keeping warning light appeared when I first started it up. Then I noticed that the yellow lane keeping light stayed on, all the backlights on the steering column remained off, and none of the controls on the steering column worked. The paddles did not function, and the ECO mode button would not work. Is there any sort of reset I can try to see if these functions return?
    20220716_155739.jpg I have had my old reliable Honda Element since 2006, and it has never done these sort of weird things. :)
    Last edited: Jul 16, 2022
  4. Disconnect the negative terminal off 12V battery for a couple of minutes, measure the residual voltage on the battery terminals while disconnected, anything below 12.6 V indicates it needs recharging. In the meantime, reconnect and use Utility mode for a few hours, should handle that task easily (look for application of ~14.6 V to the battery terminals).
    You can also put into "run" mode but a reduced voltage ~ 13.2 V may only be applied.
    I would check both accessory battery charging conditions, as it does sound like a 12V issue. Hopefully your battery was not down for too long, and can experience a complete recovery.
    Monitoring the EPCU charging algorithm via VCULDC control logic can be verified using a third party app like BM2.
    The 12V battery thread in the Kona EV forum includes a lot of diagrams using this monitor, a dedicated 12V battery thread has yet to be started in this Hyundai ionic 5 forum, although this could be the start of one;)
    Last edited: Jul 16, 2022
  5. Update: I mentioned that the car started working again, but all steering column lights and functions were not working. I managed to get an online appointment for this Thursday, but yesterday all of a sudden everything started working again. This is really confusing, and it makes me nervous about being able to depend on the car. Question: Should I go ahead and keep the appointment, even though everything is working again? That is, will the dealer be able to access data explaining what happened and whether anything needs repair. I know that in the past, mechanics had little ability to find and fix such intermittent problems. Is that still true?
    I do have a BM2 monitor coming, hopefully by tomorrow, so maybe I can accumulate some data on battery function.
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  6. Short answer...Yes
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  8. insightman

    insightman Well-Known Member Subscriber

    Longer answer: It'a a PITA, but you want to establish a paper-trail of problems in case you eventually need to have your I5 declared an official lemon. Hopefully, this temporary glitch will be the only problem you ever have.
  9. I've been sitting at the Hyundai dealer for five hours. They finally came out and told me that I'm not supposed to ever let the big battety get below 15%. That's B.S. , right?
    electriceddy likes this.
  10. I suppose they were trying to advise you the traction battery may not charge the 12 V accessory battery if left sitting below a minimum SOC which 15% may be that level. It would not be an issue to discharge the traction battery to below that level, but should recharge it to say a minimum level of ~40% immediately after driving to insure this never happens. I picked those #s out of the air, a battery monitor (BM2) should reveal if those levels are accurate or not.
  11. That may be what she was trying to say, but that's not what she said. She said it was in the manual not to let the battery get below 15%. My battery was at 14% after the trip, and it was the very next morning when I started to charge the traction battery but found the entire system had shut down. and the charge door would not even open. I have been slightly below 15% several times; One time I recall it dropping to 10%. 15% is when I usually charge it back up to 80%. I have never had the battery get low enough to trigger any of the warnings or limp mode I have read about. I'm attaching the printout of the scans, in case anyone is interested.

    My BM2 came today, so maybe I'll be able to spot this problem before it occurs again. But I hope it won't be too long before the mechanics for these cars are trained well enough to be able to do anything other than just read the codes and wiggle the wires. I'm used to knowing more about a car than the salesman does, but it's a problem when I know more than the mechanics. :) All the other folks in the waiting room kept telling me that electric cars just weren't reliable enough. That was definitely not true for my 2018 Clarity, and I still like the Ioniq 5 as well.

    Attached Files:

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  13. insightman

    insightman Well-Known Member Subscriber

    I can't believe any company would create a battery management system that would allow the driver to use so much of the battery capacity that bad things happen.

    I couldn't find the 15% danger level mentioned in the PDF Ioniq 5 Owners Manual. On page 1-9 were these two notes. I believe the first one describes the procedure required to balance the battery cells. The second one is rather vague with the word "insufficient" rather than a charge level and no definition of "a long period."


  14. That matches what I read as best I can recall. I don't know how she came up with that misinformation. Anyway, I'll set up my BM2 monitor tomorrow and see what it says in the future.

    This has been an interesting experience, but I still like the car. I might feel different if I really needed to count on it to get back and forth to work.
    electriceddy likes this.
  15. Look forward to the results to see how closely the charging algorithm diagrams match those listed in the above mentioned Hyundai Kona 12V battery thread...I suspect they will be identical and possibly more frequent when short drives are involved. Give it a few days of logging with different drive patterns and various SOC levels. These will be the first logged results listed in this forum for the Ionic 5.;)
  16. I installed the bm2 today. When I scanned the QR code in the manual, it took me to http://bmapp
    , which then took me to Tradovate install site. It was a futures trading app and asked for my credit card number. Being a little suspicious, instead, I went to the Google play store and searched for bm2. That worked. The app showed the battery voltage as 12.74, which was close to what I measured with my multimeter. I'll let it run a few days and report back here. Is this really the first test of the bm2 on an Ioniq 5? If so, maybe I should start a new thread with "BM2 test on Ioniq 5" as a subject.
    UPDATE: i tried scanning the code again, and this time it took me to the correct bm2 site. Weird.
    Last edited: Jul 22, 2022
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  17. I have had the BM2 running for a couple of weeks now, and have started a new thread to describe the results so far. https://tinyurl.com/yw2c7y8e
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  18. januszgrabon

    januszgrabon Member

    I own Ioniq 5 2022 with 7100 miles. On March 5th 2022 my car my car was towed to dealer with 12 volt battery dead in Florida. My car is AWD SE originally from New York. After 3 months car stopped charging with L2 charger. Car is still sitting in a dealer without diagnose. I have loaner from a dealership. Also I notice car have a recall for battery preconditioning. Service manager doesn't think recall will fix a problem. I did check parts department they have 12 Volt battery in stock for my car. I never discharged main battery bellow 40%. Current state of charge of main battery is 91% 220 miles range 12 Volt still dead and blue link doesn't work. I have no idea why they can't diagnose problem and fix a car. Name of the dealer Derly Hyundai 655 NE 6th Ave Delray Beach , Fl 33483. I did contact Hyundai central case#21144081 , no resonse from dealer or Hyundai Central.
    I have no idea what else I can do to get my car fix.
  19. In addition to the 12-volt battery issue, I had a problem with very slow charging rates on Electrify America DC chargers (typically only 60 KW or less on a 350 KW charger. The dealer replaced what he said was the "P.L.C. Charge Control Module." The charging speed appears to be better now. As for the 12-volt battery issue, the dealers still keep saying they can find nothing wrong. That problem is almost certainly a software issue in that the 12-volt battery charging becomes problematic whenever the traction is below some unspecified level. What Hyundai should do is give the owner an option to adjust the minimal level of the traction battery charge. If I were not retired and had to depend on the car for work, I would have pursued the lemon option and started using my reliable 2006 Honda Element again. But I have decided to keep the Ioniq for now--even with the unreliable 12-volt charging. But I have to keep the Element as a backup for whenever the 12-volt battery dies. As for the mechanics not being able to diagnose your problem, about all that dealer mechanics do these days is to plug it into the diagnostic machine and see what the computer says. In m experience, the same is true for appliances, tractors, and electronics. As an eighty-two-year-old mechanical engineer, I find that to be unfortunate.
    Domenick likes this.
  20. rcarter3636

    rcarter3636 Member

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  21. So its taken them this long to figure out Bluelink kills the 12V battery.
    I had this figured out long ago with a hung command. I have not enabled telematics on my newer model for this very reason;)
  22. januszgrabon

    januszgrabon Member

    In my case what I have to do remove blue link on my Android cell. I still don't have diagnose from a dealer . I keep all posted.
    Thanks for info,
    J grabon
  23. I think if you long press on the icon on your phone, it should give you the option to uninstall.

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