If you've had a dead 12v battery please respond

Discussion in 'Hyundai Kona Electric' started by drivingbythesun, Nov 5, 2019.

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Has your 12v battery died for no reason?

  1. Yes

    26 vote(s)
  2. No

    23 vote(s)
  3. Yes, but I left something on/it was my fault

    2 vote(s)
  1. drivingbythesun

    drivingbythesun New Member

    I see there is a long thread already on the dead 12v battery, and I will go through that next, but I wanted to get this post out there ASAP.

    My car is at the dealer right now for the second time for a dead 12v battery. Jumped by AAA the first time, checked by Hyundai, no problems. 2000 miles later, dead again, jumped by me the second time. They have had the car since Saturday and can't find anything wrong and can't replicate this issue. I get it back tomorrow morning, and if this happens again, it's getting towed back to them.

    I want to go back to them with knowledge about how many people are having this exact problem to show them that it's not just me (and it's not because a deer ran into the side of my car either like they've hinted at). If you are willing to give me your name and e-mail address in case I take this further to Hyundai customer care please PM me that information and I promise I won't do anything with it unless Hyundai asks for it. If you just want to raise your hand here and said it's happened to you, I'll just count you in my non-scientific poll. And if this has happened more than once, I certainly want to talk to you. And everyone - Amazon overnighted me (like ordered 6 pm, on my door step 6 am the next morning) a power pack (the NOCO GB40 works great!). You might want to invest in one as it seems this is not a rare thing! I'm posting this on a few places so you might see this more than once.

    Thanks for any responses!

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  3. First sorry about your 12 V issues. I have a habit of leaving my car in run mode to recharge the accessory battery at regular intervals for 2 hours a month or when the voltage is less than 12.6 V residual (no load).
    2nd , error codes as indicated by
    sounds a lot like this post
    which developed into an EPCU module replacement
    so at least one other (on this forum) has had this issue.
    I am starting to wonder if the Kona EV may be a little too active when left plugged in or a hung command such as through Bluelink.
  4. eastpole

    eastpole Active Member

    Linda, my 12V battery was dead at the time Hyundai arranged for me to pick up the car, brand new. It hasn't happened since then (~3200 km) but it certainly was irritating.

    I wonder how Hyundai ship the vehicle across the Pacific? I.e. what state of charge in the traction and auxiliary battery? Would you disconnect the auxiliary battery during the voyage?
  5. Read the Dead Kona EV thread. Could be the same thing.*I see you did.
  6. Francois

    Francois Active Member


    When you say "... leaving my car in run mode to recharge the accessory battery..."

    What do you call run mode? Is that the driving mode? Or is it the accessory mode that we trigger by pressing the power button without having our foot on break pedal?

    I think you mean the latter as I am guessing that idea is to deplete the battery a little bit, but just want to make sure I didn't get this wrong. :)
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  8. Start the car like you are going to drive it with foot ON the brake, then apply the e-brake(turns off DRLs) and shut off the center display.
    Francois likes this.
  9. milesian

    milesian New Member

    Could you describe the differences between your run mode VS utility mode, in terms of 12V battery charging behavior and otherwise?

    Sent from my ONEPLUS A5000 using Tapatalk
  10. I had this happen once; for a few days beforehand, I noticed that BlueLink was unable to get service, and the cellular modem reported its IMEI as all zeroes; I figured rebooting the car would resolve it, but normal restarts didn't. I was about to make a service appointment when the battery died overnight; a jump revived it, and conveniently fully rebooted the system such that the modem reported a real IMEI and was able to connect. It's purely speculation, but I'm slightly suspicious the battery was run down by the car attempting to find cell service; certainly that's one of the quickest ways to run down a phone battery, and while I'd be a bit surprised it would actually manage to drain the car battery, it seems plausible at least.
  11. https://insideevsforum.com/community/index.php?threads/dead-kona-ev.6991/page-2#post-78530
    I have not run the car in utility mode as of yet, but the 12 V battery seems to be charging just fine in "run" mode.
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  13. Devhead

    Devhead Member

    This sounds like the problem I experienced and discussed in "the other thread". Although, I can still only speculate since I do not have proof of the cellular connection not working. I only have the errors that were being shown on the web site and smartphone interfaces. Where do you find the IMEI information? Also, do you consider turning the car on and off 'Rebooting' or is there a way to truly reboot it other than disconnecting the 12v battery for a few seconds?
  14. drivingbythesun

    drivingbythesun New Member

    This is an interesting idea. I don't remember the specifics around the first time I had the dead battery, except it was plugged in at the time, but I do remember sometime this week when I attempted to defrost the car remotely that it couldn't complete it because it was waiting for something else to complete. But then I got the alert that it did complete it. But I can't remember if that was Monday, the day the car died, or on Saturday, the next day I drove it to take it to the dealer. And I don't see anything in my e-mail from either day. But something to keep in mind.

    Thanks! Linda
  15. You can find the IMEI info under All Menus > Setup (on the second page) > Blue Link > Modem Information on the infotainment system. In my case the signal indicator in the top right also showed no bars/an X while it was out of commission. I had hoped turning the car on and off would reboot it, but it didn't; other than having the battery die I don't know of a way to do it (although disconnecting the battery does seem likely to work).

    I could be completely off base with this, but it's the only thing short of a random bug or hardware fault I could think of that would at least somewhat make sense. Will definitely be interesting to hear if this echoes others' experiences as well!
  16. mikeselectricstuff

    mikeselectricstuff Active Member

    When the car is turned off, it draws substantial current ( several amps) from 12V, gradually decreasing over several minutes. Although a modem trying to talk wouldn't draw much power, it may be be in the critical path of the shutdown process. The current drawn shortly after poweroff would certainly be enough to drain the battery in day or so. However I think it is probably more subtle than simply not being able to communicate, as people will surely have parked in underground car parks etc. and more would have had this issue.
  17. You would think that there would be a battery management system in place that would charge the 12-Volt battery from the main battery on demand when it reaches a certain depletion level.
  18. There is. Sometimes it doesn't seem to work.
  19. Yes there is. Just push the reset button above the volume control with a paper clip (another thing to carry). This way you only have to reconfigure settings in the A/V system after restart(max charge level, default regen and winter mode - Canada)
    Detailed picture on 1 - 2 multimedia manual and details on 11 - 9 under "system is slow or it does not respond"
    For a laugh look at the next symptom - system does not turn on,where the solution is a "shorted fuse".
    Would be a first for me. usually they open due to a short:D
    lars2885 and Francois like this.
  20. I wonder if the IMEI info is displayed as well in "engineering mode", I will find out unless someone beats me to it:
    lars2885 likes this.
  21. Yes I will invest in one of these before a long trip, or something similar.
    Quick question, when you "jumped" the 12 V battery did you apply the negative lead to the battery post or chassis ground as displayed in the owners manual on page 6-5?
  22. Update - can,t find IMEI in engineering mode , but I did find a way to shut off telematics
    varient coding/ system/ telematics - on - off
    there is one in there for modem but it is blurred out.
    There is also a way to set to factory default (without using the reset button), but I didn't try it.
  23. hobbit

    hobbit Well-Known Member

    It's unclear if that "engineering mode" telematics setting has any
    real effect. There's only one way to be sure.

    In my observation it takes 15-20 minutes for enough stuff to go to
    sleep and settle down to a total draw of under 20 mA. I don't know
    if lack of the cell modem affects that time.


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