12V battery

Just an update - My replacement 2021 Ultimate has the same 12v battery problem that the old 2020 did. It occasionally gets into a loop with the Aerovironment EVSE and drains the 12v battery. Happened to me again the other day. I mostly avoid it by keeping unplugged and only charging occasionally.



I would suspect the EVSE, but as reported above, I've seen problems with Hyundai's EVSE cord too - just not as drastic.

I haven't done any of the firmware updates since I got the car, which was manufactured in late 2020. I'll take it to the dealer and see if any of those fix the problem. They didn't on the 2020, although they did change the 12v charging pattern.

 

If the suspect is some EVSE-car "chatter", it would be good to diagnose that.

 

I'd love to. But that would require a little bit of interest and technical support from Hyundai, and they offer none. In fact, Hyundai factory tech support told the dealer that this was "normal operation."

After multiple visits to the local dealer, I had to open a case with Hyundai before a Hyundai tech would talk to the service department. I showed them graphs similar to the one above, and offered them the videos posted earlier in this thread showing the car-EVSE feedback loop actually cycling. Here's the service report for that visit:



Notice the highlight; the factory tech said "AS PER AGENT KREG ... GRAPH RPOVIDED BY CUSTOMER ARE NORMAL OPERATION." Apparently, as far as Hyundai is concerned, if there is no error code then the vehicle must have been operating normally.

But this wasn't a total waste. Since the case was already open, when the high voltage battery recall opened up I was already in the system and was able to get a buyback, exchanging my 2020 for a 2021 and some cash. That's reasonable compensation for taking a few minutes to jumper start the car with a small battery pack several times a year.

 

Hey - sorry that the gift card wasn't showing up originally. And that I didn't see this post earlier. I think you should be covered now, but let me know if you have any questions for us. Thanks again for all your help!!!

 

Long since covered, Scott, and happy to help.

 

Eddy, what's the VCULDC update, and do you know when it was released?

Last month I talked to my service rep about installing all updates in my 2021 Ultimate, built in late 2020. She said there were no pending updates. I'll call her again after finding out if you have any more details on this one.

Having had a few years to think this over, if I had the Hyundai programmer on the phone I would ask him to program the car to not tell the EVSE to charge whenever the 12v battery is being charged. I bet that would fix my problem, which appears to be this loop:

• Car wakes up to charge 12v battery.
• Awakened car wakes up EVSE.
• EVSE tells car it's ready to charge.
• Car tells EVSE to start charging, and suspends 12v charging.
• Car notices it was already fully charged, and tells EVSE to stop.
• A few minutes later, car goes to sleep.

Lather, rinse, repeat.

 

Does anyone know if the vehicle is capable of 12V charging during 356V charging?

On my 4th 12V warranty battery.

 

You get 30 minutes of 12V battery charging from the start of traction battery charging.
In Utility Mode you get 12V battery charging for the entire duration while in that mode.
Parked you get 20 minutes of 12V battery charging every 4 hours for the first 60 hours, following that 20 minutes only once a day.
Run Mode seems to differ by firmware. At my 196 revision (nearly 2 years old) I get no 12V battery charging.

 

I haven't confirmed that specific situation yet but I'd be surprised if it's different.

 

DC charging puts more systems online, like battery cooling. So my presumtion is that DC-DC converter is online during fast charging.

 

Something I just noticed after 3 years: if you open any door, the LogoLight goes out!

None of the problems in this thread manifest with our Hyundai Ioniq electric. Yet.

 

Is anyone else using the included 120 V EVSE with HV battery charging current set to Minimum (on center console EV display page) to slowly charge their battery overnight (to preserve HV battery lifetime and keep battery warm on cold nights)?

Has your 12 V battery discharged, resulting in the car not turning on?

 

If you are using Bluelink to start and stop HV battery charging, has your 12 V battery discharged, resulting in the car not turning on?

Current draw should be minimal from an onboard processor for charge scheduling and management. However if Bluelink or scheduled charging keeps too many parts of the car running, the 12 v battery could be slowly drained if the DC to DC converter doesn't charge the 12v battery.

The DC to DC converter is probably not keeping the 12v battery charged (possibly because charging stops too quickly when an EVSE is left plugged in for long periods, as noted above).

 

No, but I don’t see that setting doing what you’re expecting anyway. Any level of AC charging is equally harmless. And battery losses are only 1% of the prevailing rate so you’ll struggle to warm up the uninsulated battery pack.

 

Thanks to Nickolai Zeldovich (post #193) and Toolworker (post #195) for their Bluelink comments about draining the 12v battery on this related forum
https://www.insideevsforum.com/community/index.php?threads/dead-kona-ev.6991/page-10

 

I have never employed this exact practice.

However, based on my BM2 (Bluetooth connected sensor on 12 volt battery to monitor 12 volt battery health) data and based on 1.5 years of using our 32 amp home charging setup, when the car is charged and the charging stops, the 12 volt battery goes through a slow discharge adventure that I avoid by unplugging the car once it's topped up.

 

Just got 356V battery replaced. Will cross fingers to see if the 12V battery will now charge while driving just like an ICE car.

Prior to 356V battery replacement, LogoLight seemed to be on every morning when I went to use vehicle. Now LogoLight is not on every morning! So something changed.