12V battery

I now have the latest 12V "VCULDC 00D111 Control Logic Improvement" charging algorithm that everyone else already has so I'm looking for differences. First test was the charging schedule while parked and that appears to be the same, where it reverts to once a day after 56 hours. Main battery SoC about 68%.

As @EE mentioned elsewhere, just before you take the car into the dealer it's wise to place it in Utility Mode for about an hour to give the 12V battery the best chance of surviving the inadvertent disrespect it will get. As you can see it dropped down to 12.1 V just before 9AM on the 26th, the second lowest it's ever been. The lowest, about 11.9 was when they did the last update!

 

Yikes.

My wife’s reply to this situation, “Sounds like poor planning on somebody’s part”.

I agree.

 

Well, I believe that’s what the opening underneath is for, R&R the BMS.

 

Near the left front corner if I recall. It’s the only major feature on the battery underside cover.

 

Right front

http://techno-fandom.org/~hobbit/cars/ev/167front-under.jpg

_H*

 

This guy carries on like he's discovered the "new world" when in fact Hyundai just blew him off with a standard answer.

 

Yeah, this one is so obvious even Hyundai couldn't avoid seeing it. It came up when I was beta testing for Weavegrid last year, and they reduced their Bluelink pings. I'll let them know about the 20 transaction limit.

It has nothing to do with my problem, an occasional loop between my Aerovironment EVSE and the car. It looks like one side tries to initiate a charge, but the other side responds in a way that terminates the charge. Then they do it again. Each time the car wakes up and takes a bite out of the 12v's charge, draining it in a matter of hours. Hasn't happened for a while, but I only have to charge every couple of weeks and have stopped leaving it plugged between charges.

 

After some less than optimal visits to the dealer, I was able to kill my 12V twice in 4 days, by driving home, plugging in with delayed scheduled charging active, then driving for another short trip to town, returning home, plugging in, and letting scheduled charging kick in at 11 pm. By 730 am, the 12V was flat. After boosting, each time I noted a SOC of 82%, with a set target SOC of 80% being exceeded. Ironically, the car can sit for 2 weeks with no ill effects, with normal 12V maintenance cycles, if sitting away from home, not being charged.
Tech at dealer now says I need a new "smart junction box", to be replaced under warranty because of parasitic draw.
Questions:
1) What is a smart junction box? Google didnt find anything except a video of the High Voltage and DC-DC converter module?
2) Would it be related to the Ioniq 5 ICCU root cause for those 12V failures?
My part is on order, due early April, so I'm hoping this is actually the cause.

 

We got our new 2023 Kona in January 2023 and the 12v battery went flat on us twice. I had a parasitic draw of 3 to 4 amps. After more investigation I found the problem to be the KEY FOB! We park the car in our carport and hang the FOB near the door which is maybe 12 feet away from the car. The FOB must be a good distance away (30+ ft) from the car in order to let it "sleep" (otherwise it keeps searching for the fob). We now place our fobs in a faraday box with no more 12V dead battery issues! The car searches for 10-15 mins after shut down and if can't find the fob it goes "To Sleep" and no more parasitic draw.

 

I think if it were as simple as that the forums would have far more complaints than we do now. The car's specified range to contact the smart key via is 0.7m and the key's range to contact the car when a button is pushed is 30m.

 

Weber Auto channel on YouTube recently presented some details about Tesla's lithium-Fe auxiliary battery which was enlightening as similar methods will eventually need to be adopted by other EV makers to minimise 12V battery issues. Surprisingly Tesla felt it was OK to change the long-standing "12V" system voltage to 16V, which I thought was a bit risky given that consumers expect their 12V electrical nicknacks to just "plug in and power up" without checking first, but it seems that the cell chemistry chosen left them no better option.

The most important feature mentioned is that the 16V aux battery has an internal BMS (as it would have to) and can "ask" the car to charge it up using the same type of low-power LIN communications that the 12V battery sensor does on the Kona. The difference here is that the Kona's 12V battery cannot wake up the car if it needs help. It has to wait until the next scheduled wake-up event for the car to query the lead-acid battery condition, normally every 4 or 24 hours (outside of Utility mode of course).

Weber Auto (John Kelly) didn't mention the (parked) charging regime for the Li-Fe aux battery so I tried to find out what that was. I asked over at the Tesla Motors Club and it seem no one knows for certain so I asked John about it. He says that since 2019 there is a small DC-DC converter inside the battery pack that runs all the time to supply a base load of up to 0.5 A for the 12V or 16V system without needing to liven the contactors and add other associated loads to the traction battery. Related to that, he says that using sentry mode requires that the main contactors be closed as the load is much higher.

It seems to me that the system already used in the Kona could be adapted to wake up the car as the 12V battery sensor (on the negative terminal) is alive 24/7 and knows when the aux battery is in need of a charge. I'm not certain if changing to 16V simply to use a lithium-ion aux chemistry is a good idea in terms of the customer but certainly there is a significant weight savings to losing the lead-acid battery. Perhaps with many devices using USB and V2L features that's less of a problem these days.

 

My battery has gone down to about 5V twice since my last software update in January. Once after the hood was open overnight and once after the hatch was ajar overnight. On other cars this wouldn't have drained the battery so drastically so I am wondering if this is bluelink panicking? I have never enabled bluelink but maybe the dealer did for their software update? IDK, but how does one check to see if bluelink is active, and if so how do I turn it off?

Or my theory could be totally wrong... I just don't want to be stranded in some remote location since putting it in gear and push starting it isn't an option with an EV

 

Thanks a million EE! My bluelink is off, good to know. I'll take your advice and put it in utility mode occasionally and before any service. To get the car to turn on again, both times I needed to use my 12V charger (which will live in the car now just in case). Voltage across the 12V battery terminals after the charge is exactly 12V, similar to what I see on Knoa's inspections. I think I should consider replacing the battery proactively. I'll read some of the posts here for recommendations.