[justdoit.shattuck]

This is my first post in this forum, thought by sharing our 12v battery adventure we could potentially help a few other Ioniq 5 owners out there

We purchased our Ioniq 5 2023 Limited AWD in July of 2023. Starting from Oct (4 months in) we started having 12v issues. It would die if I didn't drive the car for a day or 2. I bought myself a portable jump starter and survived a couple of months with that. But by Dec it was dying nearly every 6-8hrs. I would never see the yellow light (12v battery being charged by the big battery) at this point. The 12v was only getting charged when we were out driving the car. Battery Monitors would show a consistent trend of hourly downward spikes the battery recovers after 5-10mins but not entirely to the original level, and eventually, when this happens enough times in a row it would bring the battery down to < 10v and the car die. No dashcams or other after-market mods, not even USB cables plugged in.

After spending weeks on the phone with the dealership begging to get an appointment I was finally able to grab an appointment right before Christmas and drop the car off. The dealership performed the ICCU fix + replaced the old battery. They seemed pretty confident that the ICCU recall could fix the issue. We got the car back after a few days, and I put my Battery monitor back on. The battery looked a lot healthier I even saw the yellow 12v battery charging indicator light back on a few times. But within a day or two the battery monitor would confirm that the dips in voltage had not gone away - they occurred very regularly in an hourly interval or so, sometimes multiple times in an hour. But since we had the newer battery it was just dealing with these voltage drops a bit better. By the end of Jan 2024 (1 month since getting the new battery from the dealership) I was seeing 12v battery dropping down to 11.2-11.3v after staying parked overnight in the garage. It was pretty clear that the new battery would die on me in another month or two.

My dealership experience was pretty negative, they made me wait for weeks when living with the car was almost a hazard. And after the eventual servicing, they didn't clarify why this new 12v battery would solve the underlying problem, or what was causing this phantom power draw at such regular intervals. I remember seeing posts about frequent Bluelink activation causing 12v battery degradation - but I was also pretty sure that Hyundai claimed that they fixed this issue by limiting the number of remote requests that can be made by a Bluelink app to a fixed number per day. But at this point, I was ready to try anything sensible, so I went ahead and logged out of the Bluelink app, and changed my Bluelink password on Feb 7th.

Here is my Battery monitor chart for the last 15 days. The hourly 12v dips stopped almost immediately, that very night the DC to DC converter kicked in and charged the 12v battery for a while that night (and many more times since then) which I had only seen once since I received the new 12v battery.

View attachment 54060

For the last 4 days things have looked a lot better, I hope I'm not jinxing it 🤞

I'm no expert in the underlying technology to manage the App and the remote actions but why a status check would draw that much voltage is beyond me. I did take two actions at the same time (i.e., logging out of the Bluelink account on my phone, and changing the password) I'm not sure whether one of those actions would have sufficed.

Anyway, thought I would share. Will post an update in a few more weeks.

Not sure if you saw my post I just put on but very similar problems for me. My car is currently at the dealership. It's been there for a week now. I'm curious. After you logged out of Bluellink and you said the battery was now getting charged, was the yellow dashboard light also coming on signifying charging of the 12 volt?

 

[ashin]

Not sure if you saw my post I just put on but very similar problems for me. My car is currently at the dealership. It's been there for a week now. I'm curious. After you logged out of Bluellink and you said the battery was now getting charged, was the yellow dashboard light also coming on signifying charging of the 12 volt?

Yes, that was pretty much my experience. The regular periodic drops in the 12v voltage stopped immediately, and then the big battery started kicking in to charge the 12v very regularly - I see it both using a battery monitor (BM2) but also the orange light is on pretty frequently as well (almost too frequently to my liking) but so far everything seem to be holding up fine.

 

[Mikael48]

Has anyone else heard about the charging door sensor charade?

Yes, a frequent issue with early models, charging flap would not open after pressing it, because the flap was slightly misaligned and touch sensor was constantly depressed, which caused the 12v battery drain.

 

[Mrcorvettegolfer]

Stationary maintenance if 12V battery is in good shape will kick in whenever 12V battery drops below 12.6 V.
And if you have Hyundai GDS tool it will keep 12V battery at 92% SOC ( 1% +/-).
Just make sure that BM2 negative wire is attached to the chassis and not directly on the 12v battery negative terminal.

Why do you say that the BM2 negative has to be attached to chassis?

 

[HandyAndy]

He's explained this already, elsewhere. It's so the tiny current draw of the BM2 (a few milliamps) then flows through the current-sensing widget attached to Earth-terminal of the car, so this extra current is then detected & accounted for by the chippery & data-logging that goes on.

Connecting directly across the terminals means there's effectively a tiny internal leak inside the battery, which this widget can't detect or account for. Which for all I know might mean the widget/car thinks the battery is defective when actually it's fine!

 

[HKtech]

He's explained this already, elsewhere. It's so the tiny current draw of the BM2 (a few milliamps) then flows through the current-sensing widget attached to Earth-terminal of the car, so this extra current is then detected & accounted for by the chippery & data-logging that goes on.

Connecting directly across the terminals means there's effectively a tiny internal leak inside the battery, which this widget can't detect or account for. Which for all I know might mean the widget/car thinks the battery is defective when actually it's fine!

There is another important thing that smart sensor on negative terminal is checking. It is 12V battery internall resistance, and if this aftermarket solution is hooked over 12V negative terminal it will interfere with reading necessary to make accurate decisions on charging logic.

 

[KevinT]

Lol, if the internal charging logic worked properly we wouldn't all be hooking up BM2s to monitor our 12Vs in the first place.

 

[stressless-1]

There is another important thing that smart sensor on negative terminal is checking. It is 12V battery internall resistance, and if this aftermarket solution is hooked over 12V negative terminal it will interfere with reading necessary to make accurate decisions on charging logic.

You have mentioned your concern about measuring battery internal resistance a number of times, but with all due respect, since the internal resistance of the BM2 monitor is about a million times greater than that of a car battery, there is no way a simple car device could detect such a small difference. It would take a sophisticated physics research laboratory to detect this.

 

[Mikael48]

Parameters gathered by the small BMS box on the 12V battery negative terminal (30 days back) in the attachment.

 

[stressless-1]

Parameters gathered by the small BMS box on the 12V battery negative terminal (30 days back) in the attachment.

Thanks for the detailed information about the BMS monitor.

Perhaps I have been unlucky, but the unit on my new I6 has failed twice in the past six months, presumably causing (or contributing to) my "dead" 12V battery problems, and a total of 4 weeks in the shop. Fingers crossed.

 

[HKtech]

@stressless-1
Please note that I do not rely on the internet for my knowledge of the E-GMP platform. I would appreciate it if you could conduct more research before questioning my posts in the future. Furthermore, you have already identified the reason why the BM2 must be wired differently than what is stated in the user manual.

 

[Lanternrouge67]

First post here. Our May 2022 i5 (Premium, tech pack, 70kwh) has recently been affected by the 12v drain problem over a 2 week interval - just two instances. Both times after the key fob was used to try and unlock the car.

First time the battery flattened and Hyundai Assist were called in UK, so the AA came and rescued us, boosted battery and all was back to normal. Engineer pointed out battery only has a 2yr warranty. Drove home, booked car in for service and possible 12v battery replacement.

Took it to local dealer who tested the battery as healthy, and would not warranty replace. They also updated the ICCU software.

Fitted BM2 and made sure battery booster charged and installed in frunk.

Second time it failed at home, a few hours after using the car quite uneventfully earlier in the day. This time we had the BM2 recording, which I attach here. You will see yesterday's event as the battery drops to the point the car barely unlocked.

Used the booster and back on road again.

The graph shows all the data we have since fitting BM2 so only 1 failure state recorded. Yesterday is the lowest I have seen it drop.

Is the graph generally the profile one would expect for the battery? I note it seems mostly consistent with others I have seen (bar yesterday's outage). I can't make out a pattern of pattern of behaviour bar "car drive - graph go up" else it seems almost random to me. Sometimes draining and charging busily or just stable at around 12v.

Bluelink is connected. Interestingly, when battery drained it blasted that the car alarm had triggered - it did not. The hazard lights were on but not flashing, just solid. Guess battery too feeble at that point.

Android Widget was active until just now. Just read it may be a contributor?

Car has wireless MA-1 installed but this was so for several months of (blissfully ignorant or carefree, u decide) motoring.

No 3rd party apps polling car that I know of, certainly not for charging.

Nearly all charging is 7kWh AC, usually 1 or 2 times a week, to 80%.

So far, jumping the car has worked ok so I am not super concerned yet but as others have pointed out, seems a bit poor for a 2 year old £45k+ car albeit a new(ish) technology so some teething problems to be expected. I am more concerned about this happening late at night, in the dark wheel or raining and my partner is miles from me.

On the upside, I guess it's harder to steal in this state.

Nothing else has gone wrong, it's a joy to drive. Not looking forward to the new tyres though, it's chewing thru the rears.

12v problems seem to affect other Hyundai/Kia's too but just BEVs, so I am inclined to believe the battery's are just shoddy but others get may know more?

 

[Mikael48]

Android Widget was active until just now. Just read it may be a contributor?
Car has wireless MA-1 installed but this was so for several months of (blissfully ignorant or carefree, u decide) motoring.
No 3rd party apps polling car that I know of, certainly not for charging.

This BM2 graps is very busy, lots of automated 12V top-ups. I suggest disabling any Android Widgets, then monitoring BM2 graph for several days. Next week you should remove MA-1, too - maybe you get even flatter line?

Please test it in your car, but the wireless MA-1 might have aggravated the battery drain - every time Android widget remotely woke up the car, the MA-1 adapter probably went alive and continued running for another 5-15 minutes, depending on how long the front USB/12V outlet is energized.

 

[Lanternrouge67]

This BM2 graps is very busy, lots of automated 12V top-ups. I suggest disabling any Android Widgets, then monitoring BM2 graph for several days. Next week you should remove MA-1, too - maybe you get even flatter line?

Please test it in your car, but the wireless MA-1 might have aggravated the battery drain - every time Android widget remotely woke up the car, the MA-1 adapter probably went alive and continued running for another 5-15 minutes, depending on how long the front USB/12V outlet is energized.

Interesting observations! Battery failed just now! Partner at shops, had to do over phone battery boost walk thru. Well down lower graph. It's oddly (so far)only when my wife unlocked the car it fails. Could the key fob or her phone be a contributory cause do you think?

Edit to add BM2 screenshot, this shows yesterday's outage and now today's:

 

[Lanternrouge67]

Just tried the plugin V2L to make it charge" trick I found on various of these threads (maybe this one too, there are so many now) and yes it did indeed do the trick. Not sure if that helps.


Question to others out there such as @HandyAndy or @HKtech - does use of a battery booster after my 12v has dropped to the levels seen above damage the battery? Or is it just the fact the battery slumped to those low voltages mean its already damaged? Would you replace your battery if it behaved how mine has bearing in mind it has had 2 years or similar usage patterns as the last 2 weeks?

Is an AGM battery a sensible alternative or should one stick to stock and accept maybe we have to replace them every 2 years?

Have unplugged MA-1 to see if the battery trend alters - so far "nope" - just kept draining till I turn on car with brake pedal pressed (yellow highlight) or I plugged in V2L (blue highlight).

I am not in anyway knowledgeable enough about how these 12v devices work or what healthy looks like and I suspect we may only be seeing the graphs of unhealthy batteries in these threads perhaps? Anyone able to post a BM2 (or similar) timeseries showing what "good" looks like - preferably over more than a 7 day period of regular driving and charging?

 

[HKtech]

Once a 12V battery's voltage decreases to single digits, it has already incurred irreparable harm to its State of Health (SOH). This damage will only deteriorate over time.
More frequent maintenance and monitoring will be required if not replaced.

 

[Lanternrouge67]

Once a 12V battery's voltage decreases to single digits, it has already incurred irreparable harm to its State of Health (SOH). This damage will only deteriorate over time.
More frequent maintenance and monitoring will be required if not replaced.

Thanks for the response, funnily enough it failed again today so it's off to the dealer for a checkup and hopefully just a new 12v and nothing too complex. 🤞

 

[justdoit.shattuck]

Once a 12V battery's voltage decreases to single digits, it has already incurred irreparable harm to its State of Health (SOH). This damage will only deteriorate over time.
More frequent maintenance and monitoring will be required if not replaced.

Good to know. Thanks.
Steve

 

[Mikael48]

It's oddly (so far)only when my wife unlocked the car it fails. Could the key fob or her phone be a contributory cause do you think?

Make sure your wife puts the car immediately in READY state when she enters the car.

 

[Lanternrouge67]

Make sure your wife puts the car immediately in READY state when she enters the car.

Yes we have been doing that.

And today it failed for me so it's not for any particular key fob/person that the battery fails.

We have now both logged out of Bluelink to see if the "busy" discharge/charge cycles level off. That was promoted by this link: https://insideevs.com/news/658984/hyundai-finds-causes-for-ioniq-5-12v-battery-drain-reveals-fixes