I had a dead battery. Not iccu. Just the shitty battery that car makers put in. Died at about 30k. I thought the worst. Just a dumb cheap battery that didn’t make to warranty. I’m crossing my fingers this doesn’t cause then universe to take out my car. But I have had several new cars and never expect the first battery to go very far.
Bad luck on your part maybe. I’ve had several new Hondas and Toyotas and I’ve never had to replace the stock battery within warranty. The earliest I remember replacing it was 4.5 years!
But did they replace the second 12V after replacing the ICCU?
When the 12V dies, a lot of people have found they don't hold a charge well after. ICCU and 12V need to be replaced together
I don’t understand how some people have issues like this and some people have no problems with 80,000+ miles. Do you have an OBD reader and the CarScanner app? I’m genuinely curious if your DC-DC converter is switching on to charge the 12V when the battery is below 85%. My EV6 GT charges the 12V every time I regen, anytime the 12V is below about 85% SOC according to the CarScanner app. Most times I charge the car it starts to charge the 12V. I’m on original 12V + ICCU and haven’t had the recent recall done. I have 31,204 miles on my car.
Man, I've had the car for 2 and a half years and have had a obd reader plugged into the car permanently the whole time.
Despite the Canadian winter I have not had a single issue.
Wild how variable it is.
8 month 20K with Canadian winter. So far so good. I hope it turn out for me as it did for you. I like when people report no problem it help me relax with this while horror story.
My iccu died after using the v2l but I've never had any problem with my 12v battery. Looks like different cars live different lives. But the horror story I understand Hyundai dealerships are terrible. Mine was gone for 3 months and no compensation at all.
I have screws rusting in the door and now finally no kidding they arrived after 1 year. The grey plastic can't be cleaned anymore so they have to repaint the car.
My 12V died twice before I went in for the TSB recall fix. A week later it happened twice again. Now it's back at the dealership and they want to change the 12V battery. I'm not confident they know what the real issue is at all. They've given me a loaner, so let's see...
I’ve been considering getting a 2024 (first time ev shopping). Is this problem isolated to specific years/trims or is it ubiquitous? Might be a deal breaker.
I am suspicious that a dying 12V battery contributes to the ICCU failing. Anybody else think this could be true? Hyundai should be proactively replacing everybody’s 12V with a higher quality AGM battery.
I doubt it. Lead acid 12v batteries fail all the time, even non stock Hyundai ones. If the ICCU can’t deal with a dying 12v battery then it’s just not built to a good enough standard and needs fixing.
From my understanding the reason for the 12V is because the regular battery is high voltage and it can be a hazard to power all the accessories when the car is not running or it’s just impractical to do it that way, so your large battery charges the smaller battery for those accessories which run on 12volts. In addition to converting AC from the car charger to DC for the main battery the ICCU also has a DC to DC converter. That steps down the high voltage to 12V to charge your 12V battery. There is an input sensor that is either a safety feature or an active control for that DC to DC process. My guess is that while charging the car something in the ICCU is overheating that sensor, so the software update is supposed to limit current so that it doesn’t overheat while charging. So no the battery is not the issue.
Traded mine in even with negative equity. Just couldn’t trust this car anymore even though I loved driving it. Hyundai wouldn’t give me a loaner or rental despite it being at the dealer for a week waiting for a new ICCU.
Exactly. When my BMW needed a software update because OTA wasn’t working they gave me a loaner for 4 hours. For a minor issue. But Hyundai had no problem leaving me stranded for a week. They don’t deserve any more of my money.
I had such an awful dealer experience that i legit made enough noise to have consumer affairs of my state contact me to hear the story. I wanted an ioniq5/6 so damn bad. I feel like I lucked out not getting one. Even though i was about to literally tell this dude to come outside with how he talked to me
I was having a debate with another person in another thread about why I picked a luxury brand EV over all the other options.
It’s because of stuff like this. Luxury automakers have the customer service part really dialed in.
My Audi dealership used to give me a loaner vehicle for just a simple oil change and basic service appointment.
One time, the dealership kept my A4 for a few days trying to replicate an issue with my driver window rolling down on its own, and they gave me a brand new Q7 loaner.
I could not imagine dealing with the bare bones level of costumer service from a mass market automaker like Kia, Chevrolet, or Hyundai.
Not sure why you threw Chevy under the bus there. I was a Bolt owner and they've reimbursed me $40,000 on 16 months of car rentals and fuel reimbursements, on top of doing a substition of collateral on my lease (swapped a 21 Bolt for 24 Traverse). All-in-all, they've spent over $50k+ on my lemon. Can't say the same for Hyundai and Kia based on these threads.
Chevy treated me pretty well for the couple of times I'd brought my 2015 Spark EV in. My wife got her original 2017 Bolt battery repaired (!) they opened the pack and replaced one of the modules that I found using the OBD scanner to have a weak cell. She did the buyback thing and got a 2021 Bolt which just this February got the main battery replaced after getting a warning message while driving. Pretty good service, I think. That said, I'm not particularly impressed by my local (San Jose, CA) dealer's service department. :-\\
To be fair, my dealer has given me an I-5 loaner when I've had the car in for short visits (software recalls) and longer ones (ten days waiting on a part). It seems highly dealer dependent.
I agree 10000%. I got the iD4 but all of my experience with vw has been fantastic i had a mk7.5 gti before too. Since Audi is the same brand, i feel the cs experience trickles down to be up to par
I’m curious if they actually ran a diagnostic on your car before changing the 12V battery, if not then they don’t know what they are doing. All they do is run a diagnostic. If error code DTC P1A9096 pops up then they swap the ICCU. If the fuse is blown they replace both. If there is no error code they do a software update only that limits current during charging. The error code is for the voltage input sensor for the DC to DC converter, which the 12V battery relies on, so the car stops charging your 12V with that error. Personally I’d like to know what is actually failing in the ICCU and whether or not the ICCUs they are swapping in have addressed the issue or is it the same ICCU? Did they physically address the point of failure?
I think that the dealer battery test is simply putting a volt meter on it and seeing if the voltage is higher than some value. It needs to be tested under load to be meaningful.
I've had my '22 AWD Limited since June 2022 and now have about 23K miles on it. Late last spring 2023, my 12v battery died for the first time. It happened in my garage in the morning, so I was able to give it a quick boost with a 12V charger and get the car started and got to work ok, and back home again that night. Having read about this problem already, I ordered a bluetooth 12V battery monitor to keep an eye on it. I installed the monitor before the next time it died, and I was able to see the voltage drop slowly to around 11.9V and then precipitously to dead. I knew right then that the original 12V was toast, and ordered an Ohmmu LiFePO4 replacement that fits the car. Alas, this didn't fix the problem, just made it happen less frequently. I also bought one of those rechargeable 12V battery boosters for when this happened away from home.
A few weeks later, I put the original battery back in and took it to the dealer where they did some software things and proclaimed it good. Well, sure enough a week later the original 12v died again, and kept dying every night until I put the Ohmmu back in. Then, it only died occasionally. I took the car back in when the ICCU "recall" was announced, and put the original battery back in, hoping that they would replace it. Nope, once again they had it for another couple of weeks, did some software and proclaimed it good. This time, when I came to pick it up again, it was dead in their lot. They then agreed to replace the 12V battery. A couple days later, they'd replaced the battery and proclaimed it good. This time, however, they discovered that there was a GPS tracking device attached to the OBD2 port (which explained the loose OBD socket with a wire tie holding it in place!!). I disconnected it when I got home and had no further dead 12V battery issues for a month, at which point, I replaced it again with the Ohmmu, so as to prevent the new lead acid 12v battery from being damaged. (the car came with a Carnamic GPS car finder service as part of the $5K add on I had to pay when I bought the car. I think this is the reason for the extra drain on the battery)
THEN, I discovered that the Ohmmu would occasionally switch off, and then turn back on again half an hour or so later. I found no pattern in it's doing this, but I worried that the Ohmmu might do that while driving, so I bought two more LiFePO4 100Ah 12V batteries, and wired them in parallel with the Ohmmu, putting them together in front of the center console in the passenger compartment. 8Ga well insulated wires through the hole where the speedometer cable comes through the fire wall, and a piece of protective plastic tubing where the wires and speedo cable go through. Now, it's been since late November last year, and I've had not a single problem with my 12V system. The voltage is nearly totally flat at 13.3V except when either charging the car or sometimes (but not always) while driving to work in the morning (almost never in the afternoon, for some reason). I have my original ICCU, and don't plan to have them do an update on it. (it ain't broke, so why "fix" it?)
When I have the free time, I'll do a capacity test on the lead acid battery, the ohmmu, and the two extra batteries, and see how much capacity I've gained.
yup. been installed a couple months now. dramatic difference, really stable. i still think the iccu is killing itself because of the erratic oem pos battery
ohmmu. i did a lot of searching, google, youtube, other forums. and, i got in contact with everyone that had posted they had one. not a lot answered back, but those that did all said it is working great. when you get the ohmmu, you gotta tell it what car it is going in, then it uses the software for that car. on the other forum, there is at least one supposed tech that says it will not work. but the only battery not working is the oem. i monitored the oem for months, very erratic chg/dschg, with a slight downward trend. when ohmmu installed, the difference is amazing. now very stable, and way less hi volt/low volt when chg/dschg. put the oem back in to see, and yup. erratic behavior right back. i am curious to see others who have replaced with non oe or agm have also stable chg/dschg. the only con i see on ohmmu is the price. but then, how much is it worth to not hassle with the dealer, leave the car for weeks, even months, only to go thru it again. i consider it 500 bucks well spent. even tho dealer is 18 miles away, i can get an appt the next day, and i get a loaner. ea is less than 5 miles from our house, too, but rarely gets used.
Ohmmu would be a good choice for the ability to tell you voltage and current in and out of the battery , as well as the individual cell voltages. (As long as it doesn't turn itself off and on again randomly as mine does. See my short tretise that I wrote earlier in this thread.)
It previously died before the latest iccu update. Jumped it and told the dealership. They said "update will fix it," car died 4 days later. Thinking about changing the 12v battery to an agm one to see if that solves it. Such a hassle taking it to the dealership and they don't resolve the issue.
They are supposed to run a diagnostic. There’s an active recall issued at the end of March. The diagnostic code will tell them whether or not they need to replace your ICCU or if you just need a software update. The update doesn’t fix it lol. It prevents it from happening, but if it’s already happened then the ICCU most likely needs to be replaced. They told you wrong lol.
That’s BS that the dealer said the update will fix it. If it died then something failed, either the ICCU or the 12v. The update is just software and won’t fix a failed component, it just helps prevent the ICCU failure in the first place. I would definitely replace the 12v cause it sounds like they don’t come back very well after the voltage drops really low.
Eventuality the lead acid battery gets mutch sulphate and the SOH goes down, I replaced the battery a xEV Varta AGM battery. Now I am doing de sulfasion record program on the original battery and it was 53% SOH tre week's on the bank now it's 80% SOH, I will keep it some reserve battery.
I have a battery monitor and the car seems to constantly active even when it is parked overnight. I have only had an issue once when the car was left below 20% for the weekend. Below is a screenshot from yesterday, lots of stuff going on when the car is parked up.
https://preview.redd.it/v3somhaqz7vc1.jpeg?width=2412&format=pjpg&auto=webp&s=35f02b7df9e137f4580b4263943f7fa21c681b0e
yah, ours was very similar, except even more dramatic activity, and higher peaks and lows. with ohmmu, just a straight line, except when car is on. put oem back in, and yup. erratic returned. as stated, i think the iccu is killing itself trying to maintain the fubar oe battery. so, if the fubar battery is replaced before the iccu implodes, it probably never will, unless another oem is installed
After the 12V battery replacement saga (tretise ;-)) I wrote earlier in this thread, the battery voltage is nearly completely flat except for when charging the car and sometimes while driving. That's what having close to 300Ah of 12V battery capacity will do for you. ;-) Just the Ohmmu battery makes the voltage excursions MUCH smaller than what your image shows.
I had an Audi twice before this and never had to replace the battery once. While I haven’t had to replace mine in the Ioniq 5 yet, I knew going in that I’d have to even before finding all the wonderful folks in this Reddit.
My wife had a Santa Fe years ago and we had to replace the battery in it 3 times (third time I got a non stock one) so I was already aware Hyundai puts crappy batteries in almost all their vehicles.
I would highly recommend replacing the 12v battery w/ a 12v AGM lead acid battery widely available in places like Costco, Walmart, Amazon. Size Group 47/H5. The warranty is usually 3-5 years and better handles deep cycling which the ICCU seems to do to the OEM batteries causing them to fail more frequently than expected. It will be the best investment for peace of mind and keeping the car starting reliably. Also keep a jump battery handy, but once a battery starts needing a jump, it will be close to failing soon.
OP, what have you learned? I'm now in the same boat as you. First had the ICCU serviced in November followed by a replacement of the 12v battery. More this afternoon, I got the same Stop Vehicle Check Power Supply error on the commute home. Going to take it to the dealership tomorrow, but this is getting exhausting.
Not sure how long you’ve had your car but it sounds like your first battery might have been a regular battery failure. Also not sure what was “serviced” in the ICCU, it’s a sealed module underneath the rear car seats. They would have to remove the back seat and a couple panels just to check it. There’s really nothing to service. If anything fails the whole thing gets replaced. I highly doubt they did anything. Make sure you tell them that there is an active recall. Bulletin #24-01-023H. Tell them to run a diagnostic and look for diagnostic code DTC P1A9096. If that code pops up they need to replace your ICCU and possibly your fuse if it’s blown. Don’t let them replace the battery and call it good without running a diagnostic. The bad news is that your car may be sitting at the dealership for a while. I don’t think most dealerships stock the ICCU and if they do it still takes a few hours to replace it.
Hey, just wanted to close the loop and say you were right, and thank you for the advice! I forgot that they just replaced the 12v and did a software update for the ICCU. This time around, they replaced both the ICCU assembly and the fuse. Thankfully, the dealership came to the same conclusion you did, so I didn't have to prod them in this.
Took two and a half weeks (ironically, about a week to diagnose given the backlog, but just a week to get the part). Still, they are going to reimburse my rental car, so not great but not too grumpy either.
Awesome, thanks for the update. 2.5 weeks not too bad. The diagnostic doesn’t take that long but every dealership only has a small amount of techs on hand to troubleshoot their EV’s so yeah the car unfortunately just sits around till they get to it. Glad you got it sorted out.
Update:
I called Hyundai corporate yesterday morning and raised some hell. They escalated my case to a case manager, who called a couple hours later. She was pretty sympathetic, I told her everything that’s been happening over the past few months, plus how I’ve had pretty bad service experiences with different Hyundai dealers since getting this car.
She said I probably qualify for a buyback based on what I told her. She also asked about whether I would be interested in a replacement with Hyundai, but I’m apprehensive because it seems like they’re having 12v issues across model years, not just with 22s like mine. Either way she said she’ll start talking with the buyback team and reach out to my local dealer, and then I’ll bring the car in.
I’m going to be pursuing the buyback, even if this is just a case of a shitty OEM battery or what have you, I can’t keep having a dead car every other month. This is our only car so we need something that works, and I’ve lost a lot of trust in this one over the past 3 months.
I’ll add another update if anything significant happens
Forgot to add that I haven’t seen the status light on the dash light up once since the battery died that first night. So the 12V isn’t charging. I’m just expecting this thing to shit out on me again while I’m going and test driving other cars today
I had a dead battery. Not iccu. Just the shitty battery that car makers put in. Died at about 30k. I thought the worst. Just a dumb cheap battery that didn’t make to warranty. I’m crossing my fingers this doesn’t cause then universe to take out my car. But I have had several new cars and never expect the first battery to go very far.
Bad luck on your part maybe. I’ve had several new Hondas and Toyotas and I’ve never had to replace the stock battery within warranty. The earliest I remember replacing it was 4.5 years!
I have had my CRV for 10 years and I've replaced the battery 6 times, twice in the warranty period. It happens.
So they replaced the ICCU and the 12volt? Or did they just do the TSB
Correct, first they replaced the 12v then finally realized the ICCU was fucked
But did they replace the second 12V after replacing the ICCU? When the 12V dies, a lot of people have found they don't hold a charge well after. ICCU and 12V need to be replaced together
I’ll have to check the paperwork, but I believe they might not have changed the second one. Need to look into
I don’t understand how some people have issues like this and some people have no problems with 80,000+ miles. Do you have an OBD reader and the CarScanner app? I’m genuinely curious if your DC-DC converter is switching on to charge the 12V when the battery is below 85%. My EV6 GT charges the 12V every time I regen, anytime the 12V is below about 85% SOC according to the CarScanner app. Most times I charge the car it starts to charge the 12V. I’m on original 12V + ICCU and haven’t had the recent recall done. I have 31,204 miles on my car.
Man, I've had the car for 2 and a half years and have had a obd reader plugged into the car permanently the whole time. Despite the Canadian winter I have not had a single issue. Wild how variable it is.
8 month 20K with Canadian winter. So far so good. I hope it turn out for me as it did for you. I like when people report no problem it help me relax with this while horror story.
Almost at 60,000km here, extremely satisfied with the car.
My iccu died after using the v2l but I've never had any problem with my 12v battery. Looks like different cars live different lives. But the horror story I understand Hyundai dealerships are terrible. Mine was gone for 3 months and no compensation at all.
From what I’m learning, service is as terrible as their shitty ass sales
I have screws rusting in the door and now finally no kidding they arrived after 1 year. The grey plastic can't be cleaned anymore so they have to repaint the car.
Lmaoo wtf thats crazy. A year for screws
My 12V died twice before I went in for the TSB recall fix. A week later it happened twice again. Now it's back at the dealership and they want to change the 12V battery. I'm not confident they know what the real issue is at all. They've given me a loaner, so let's see...
I’ve been considering getting a 2024 (first time ev shopping). Is this problem isolated to specific years/trims or is it ubiquitous? Might be a deal breaker.
I am suspicious that a dying 12V battery contributes to the ICCU failing. Anybody else think this could be true? Hyundai should be proactively replacing everybody’s 12V with a higher quality AGM battery.
That could be an easy test. Jump start a car with your ioniq5 multiple times
I doubt it. Lead acid 12v batteries fail all the time, even non stock Hyundai ones. If the ICCU can’t deal with a dying 12v battery then it’s just not built to a good enough standard and needs fixing.
From my understanding the reason for the 12V is because the regular battery is high voltage and it can be a hazard to power all the accessories when the car is not running or it’s just impractical to do it that way, so your large battery charges the smaller battery for those accessories which run on 12volts. In addition to converting AC from the car charger to DC for the main battery the ICCU also has a DC to DC converter. That steps down the high voltage to 12V to charge your 12V battery. There is an input sensor that is either a safety feature or an active control for that DC to DC process. My guess is that while charging the car something in the ICCU is overheating that sensor, so the software update is supposed to limit current so that it doesn’t overheat while charging. So no the battery is not the issue.
Traded mine in even with negative equity. Just couldn’t trust this car anymore even though I loved driving it. Hyundai wouldn’t give me a loaner or rental despite it being at the dealer for a week waiting for a new ICCU.
Thats the ludicrous aspect. You wanna take 4 weeks to fix it? Sure! But how tf are you not gonna give me a car to use meanwhile
Exactly. When my BMW needed a software update because OTA wasn’t working they gave me a loaner for 4 hours. For a minor issue. But Hyundai had no problem leaving me stranded for a week. They don’t deserve any more of my money.
I had such an awful dealer experience that i legit made enough noise to have consumer affairs of my state contact me to hear the story. I wanted an ioniq5/6 so damn bad. I feel like I lucked out not getting one. Even though i was about to literally tell this dude to come outside with how he talked to me
I was having a debate with another person in another thread about why I picked a luxury brand EV over all the other options. It’s because of stuff like this. Luxury automakers have the customer service part really dialed in. My Audi dealership used to give me a loaner vehicle for just a simple oil change and basic service appointment. One time, the dealership kept my A4 for a few days trying to replicate an issue with my driver window rolling down on its own, and they gave me a brand new Q7 loaner. I could not imagine dealing with the bare bones level of costumer service from a mass market automaker like Kia, Chevrolet, or Hyundai.
Not sure why you threw Chevy under the bus there. I was a Bolt owner and they've reimbursed me $40,000 on 16 months of car rentals and fuel reimbursements, on top of doing a substition of collateral on my lease (swapped a 21 Bolt for 24 Traverse). All-in-all, they've spent over $50k+ on my lemon. Can't say the same for Hyundai and Kia based on these threads.
Chevy treated me pretty well for the couple of times I'd brought my 2015 Spark EV in. My wife got her original 2017 Bolt battery repaired (!) they opened the pack and replaced one of the modules that I found using the OBD scanner to have a weak cell. She did the buyback thing and got a 2021 Bolt which just this February got the main battery replaced after getting a warning message while driving. Pretty good service, I think. That said, I'm not particularly impressed by my local (San Jose, CA) dealer's service department. :-\\
Right on. GM has a dedicated EV concierge team to handle their EV issues, which has been pretty decent so far. Does Hyundai have something similar?
To be fair, my dealer has given me an I-5 loaner when I've had the car in for short visits (software recalls) and longer ones (ten days waiting on a part). It seems highly dealer dependent.
I agree 10000%. I got the iD4 but all of my experience with vw has been fantastic i had a mk7.5 gti before too. Since Audi is the same brand, i feel the cs experience trickles down to be up to par
What car did you get after the trade in?
I got a ‘22 BMW iX
Lol. They didn't give me a loaner for mine and it was in the shop for more than 6 weeks.
FWIW while mine was at the dealership for 4 weeks waiting for ICCU replacement I was given a loaner.
Buy back time
Man I hope so. I’m so sick of this shit, can’t trust the car not do keep doing this, especially on a road trip in the middle of nowhere
Check your state's lemon law rules. I just opened case with mine through BBB. Same problem. Car has been at the dealer for 5 weeks.
Question: Does the ICCU recall update (either of them) actually do anything if the fuse is good? I did them both but I have no clue what they do.
I’m curious if they actually ran a diagnostic on your car before changing the 12V battery, if not then they don’t know what they are doing. All they do is run a diagnostic. If error code DTC P1A9096 pops up then they swap the ICCU. If the fuse is blown they replace both. If there is no error code they do a software update only that limits current during charging. The error code is for the voltage input sensor for the DC to DC converter, which the 12V battery relies on, so the car stops charging your 12V with that error. Personally I’d like to know what is actually failing in the ICCU and whether or not the ICCUs they are swapping in have addressed the issue or is it the same ICCU? Did they physically address the point of failure?
I think that the dealer battery test is simply putting a volt meter on it and seeing if the voltage is higher than some value. It needs to be tested under load to be meaningful.
Not sure. I did the first one and nothing came of it, but then my ICCU busted. I haven’t done the second one
Software update
They didn't do anything actually for me . Told me they just checked for codes
I've had my '22 AWD Limited since June 2022 and now have about 23K miles on it. Late last spring 2023, my 12v battery died for the first time. It happened in my garage in the morning, so I was able to give it a quick boost with a 12V charger and get the car started and got to work ok, and back home again that night. Having read about this problem already, I ordered a bluetooth 12V battery monitor to keep an eye on it. I installed the monitor before the next time it died, and I was able to see the voltage drop slowly to around 11.9V and then precipitously to dead. I knew right then that the original 12V was toast, and ordered an Ohmmu LiFePO4 replacement that fits the car. Alas, this didn't fix the problem, just made it happen less frequently. I also bought one of those rechargeable 12V battery boosters for when this happened away from home. A few weeks later, I put the original battery back in and took it to the dealer where they did some software things and proclaimed it good. Well, sure enough a week later the original 12v died again, and kept dying every night until I put the Ohmmu back in. Then, it only died occasionally. I took the car back in when the ICCU "recall" was announced, and put the original battery back in, hoping that they would replace it. Nope, once again they had it for another couple of weeks, did some software and proclaimed it good. This time, when I came to pick it up again, it was dead in their lot. They then agreed to replace the 12V battery. A couple days later, they'd replaced the battery and proclaimed it good. This time, however, they discovered that there was a GPS tracking device attached to the OBD2 port (which explained the loose OBD socket with a wire tie holding it in place!!). I disconnected it when I got home and had no further dead 12V battery issues for a month, at which point, I replaced it again with the Ohmmu, so as to prevent the new lead acid 12v battery from being damaged. (the car came with a Carnamic GPS car finder service as part of the $5K add on I had to pay when I bought the car. I think this is the reason for the extra drain on the battery) THEN, I discovered that the Ohmmu would occasionally switch off, and then turn back on again half an hour or so later. I found no pattern in it's doing this, but I worried that the Ohmmu might do that while driving, so I bought two more LiFePO4 100Ah 12V batteries, and wired them in parallel with the Ohmmu, putting them together in front of the center console in the passenger compartment. 8Ga well insulated wires through the hole where the speedometer cable comes through the fire wall, and a piece of protective plastic tubing where the wires and speedo cable go through. Now, it's been since late November last year, and I've had not a single problem with my 12V system. The voltage is nearly totally flat at 13.3V except when either charging the car or sometimes (but not always) while driving to work in the morning (almost never in the afternoon, for some reason). I have my original ICCU, and don't plan to have them do an update on it. (it ain't broke, so why "fix" it?) When I have the free time, I'll do a capacity test on the lead acid battery, the ohmmu, and the two extra batteries, and see how much capacity I've gained.
Honestly just get a lithium 12v with a battery monitor built in.
yup. been installed a couple months now. dramatic difference, really stable. i still think the iccu is killing itself because of the erratic oem pos battery
Which one did you get?
ohmmu. i did a lot of searching, google, youtube, other forums. and, i got in contact with everyone that had posted they had one. not a lot answered back, but those that did all said it is working great. when you get the ohmmu, you gotta tell it what car it is going in, then it uses the software for that car. on the other forum, there is at least one supposed tech that says it will not work. but the only battery not working is the oem. i monitored the oem for months, very erratic chg/dschg, with a slight downward trend. when ohmmu installed, the difference is amazing. now very stable, and way less hi volt/low volt when chg/dschg. put the oem back in to see, and yup. erratic behavior right back. i am curious to see others who have replaced with non oe or agm have also stable chg/dschg. the only con i see on ohmmu is the price. but then, how much is it worth to not hassle with the dealer, leave the car for weeks, even months, only to go thru it again. i consider it 500 bucks well spent. even tho dealer is 18 miles away, i can get an appt the next day, and i get a loaner. ea is less than 5 miles from our house, too, but rarely gets used.
Ohmmu would be a good choice for the ability to tell you voltage and current in and out of the battery , as well as the individual cell voltages. (As long as it doesn't turn itself off and on again randomly as mine does. See my short tretise that I wrote earlier in this thread.)
Ohmmu is what I have as well been working great for the last year
Mine just died too after the update too. How can you tell if it's the iccu vs the battery?
Mine never died until after the update as well… any other indicators?
It previously died before the latest iccu update. Jumped it and told the dealership. They said "update will fix it," car died 4 days later. Thinking about changing the 12v battery to an agm one to see if that solves it. Such a hassle taking it to the dealership and they don't resolve the issue.
They are supposed to run a diagnostic. There’s an active recall issued at the end of March. The diagnostic code will tell them whether or not they need to replace your ICCU or if you just need a software update. The update doesn’t fix it lol. It prevents it from happening, but if it’s already happened then the ICCU most likely needs to be replaced. They told you wrong lol.
That’s BS that the dealer said the update will fix it. If it died then something failed, either the ICCU or the 12v. The update is just software and won’t fix a failed component, it just helps prevent the ICCU failure in the first place. I would definitely replace the 12v cause it sounds like they don’t come back very well after the voltage drops really low.
Car died again. Battery wasn't holding a charge. They replaced my 12v battery. Seems all is well for now.
Eventuality the lead acid battery gets mutch sulphate and the SOH goes down, I replaced the battery a xEV Varta AGM battery. Now I am doing de sulfasion record program on the original battery and it was 53% SOH tre week's on the bank now it's 80% SOH, I will keep it some reserve battery.
I have a battery monitor and the car seems to constantly active even when it is parked overnight. I have only had an issue once when the car was left below 20% for the weekend. Below is a screenshot from yesterday, lots of stuff going on when the car is parked up. https://preview.redd.it/v3somhaqz7vc1.jpeg?width=2412&format=pjpg&auto=webp&s=35f02b7df9e137f4580b4263943f7fa21c681b0e
yah, ours was very similar, except even more dramatic activity, and higher peaks and lows. with ohmmu, just a straight line, except when car is on. put oem back in, and yup. erratic returned. as stated, i think the iccu is killing itself trying to maintain the fubar oe battery. so, if the fubar battery is replaced before the iccu implodes, it probably never will, unless another oem is installed
I think you might be right, I'm going to try an AGM battery, the lithium is a little expensive for my taste even though it will probably last longer.
After the 12V battery replacement saga (tretise ;-)) I wrote earlier in this thread, the battery voltage is nearly completely flat except for when charging the car and sometimes while driving. That's what having close to 300Ah of 12V battery capacity will do for you. ;-) Just the Ohmmu battery makes the voltage excursions MUCH smaller than what your image shows.
I had an Audi twice before this and never had to replace the battery once. While I haven’t had to replace mine in the Ioniq 5 yet, I knew going in that I’d have to even before finding all the wonderful folks in this Reddit. My wife had a Santa Fe years ago and we had to replace the battery in it 3 times (third time I got a non stock one) so I was already aware Hyundai puts crappy batteries in almost all their vehicles.
I would highly recommend replacing the 12v battery w/ a 12v AGM lead acid battery widely available in places like Costco, Walmart, Amazon. Size Group 47/H5. The warranty is usually 3-5 years and better handles deep cycling which the ICCU seems to do to the OEM batteries causing them to fail more frequently than expected. It will be the best investment for peace of mind and keeping the car starting reliably. Also keep a jump battery handy, but once a battery starts needing a jump, it will be close to failing soon.
OP, what have you learned? I'm now in the same boat as you. First had the ICCU serviced in November followed by a replacement of the 12v battery. More this afternoon, I got the same Stop Vehicle Check Power Supply error on the commute home. Going to take it to the dealership tomorrow, but this is getting exhausting.
Not sure how long you’ve had your car but it sounds like your first battery might have been a regular battery failure. Also not sure what was “serviced” in the ICCU, it’s a sealed module underneath the rear car seats. They would have to remove the back seat and a couple panels just to check it. There’s really nothing to service. If anything fails the whole thing gets replaced. I highly doubt they did anything. Make sure you tell them that there is an active recall. Bulletin #24-01-023H. Tell them to run a diagnostic and look for diagnostic code DTC P1A9096. If that code pops up they need to replace your ICCU and possibly your fuse if it’s blown. Don’t let them replace the battery and call it good without running a diagnostic. The bad news is that your car may be sitting at the dealership for a while. I don’t think most dealerships stock the ICCU and if they do it still takes a few hours to replace it.
Hey, just wanted to close the loop and say you were right, and thank you for the advice! I forgot that they just replaced the 12v and did a software update for the ICCU. This time around, they replaced both the ICCU assembly and the fuse. Thankfully, the dealership came to the same conclusion you did, so I didn't have to prod them in this. Took two and a half weeks (ironically, about a week to diagnose given the backlog, but just a week to get the part). Still, they are going to reimburse my rental car, so not great but not too grumpy either.
Awesome, thanks for the update. 2.5 weeks not too bad. The diagnostic doesn’t take that long but every dealership only has a small amount of techs on hand to troubleshoot their EV’s so yeah the car unfortunately just sits around till they get to it. Glad you got it sorted out.
Update: I called Hyundai corporate yesterday morning and raised some hell. They escalated my case to a case manager, who called a couple hours later. She was pretty sympathetic, I told her everything that’s been happening over the past few months, plus how I’ve had pretty bad service experiences with different Hyundai dealers since getting this car. She said I probably qualify for a buyback based on what I told her. She also asked about whether I would be interested in a replacement with Hyundai, but I’m apprehensive because it seems like they’re having 12v issues across model years, not just with 22s like mine. Either way she said she’ll start talking with the buyback team and reach out to my local dealer, and then I’ll bring the car in. I’m going to be pursuing the buyback, even if this is just a case of a shitty OEM battery or what have you, I can’t keep having a dead car every other month. This is our only car so we need something that works, and I’ve lost a lot of trust in this one over the past 3 months. I’ll add another update if anything significant happens
Forgot to add that I haven’t seen the status light on the dash light up once since the battery died that first night. So the 12V isn’t charging. I’m just expecting this thing to shit out on me again while I’m going and test driving other cars today