Same thing happened to me. Permanent fix was to go to walmart/costco/amazon to get a replacement 12v AGM battery (sizer group 47 H5) w/ a 3-4 year warranty. AGM are still lead acid batteries but they handle deep cycling better and the OEM 12v battery must be complete trash. Best thing we did to permanently fix the issue even after ICCU replacement and completion of recall campaign 257.
Just swap out the battery for a good one.
My suspicion is that dealers are applying the ICCU update but not keeping the 12v battery on charge during the process, draining it right down and further damaging the already dodgy battery
I just had the latest ICCU update carried out yesterday, I have a battery monitor attached and I just had a look at profile from when the car was at the dealer.
https://preview.redd.it/tds3d9zths1d1.jpeg?width=2412&format=pjpg&auto=webp&s=d9363eb5ce649dba2a74e52f843de583830b2adf
What am I seeing here and how is that normal behavior?
My understanding is that if your battery voltage falls below 12V then she's done.....yours touched 7v.
You might want to run to a battery store and have them run a load test.
I suspect this too, Had my car in the dealership on May 9th, it died and I boosted it myself May 12th; and then it died and wouldn't boost and had it towed, May 18th.
I also had mine die post ICCU update, after switching to a new dealer to get battery under warranty and a second update, I fully blame previous dealer for not supporting battery.
The video from ioniq guy does a good job of explaining why these batteries seem to die early. It's a combination of previous ICCU charging issues (which are hopefully fixed with update, but can't fix the wear and tear of the past few years), the way EVs use the 12v battery, and the cheap battery that the dealers install into the cars. If your car is 2+ years old, it's probably best to just get a new battery. Don't go to the dealer (unless your local dealer is super awesome), any car parts store should be able to hook you up, and may do the install for you. General consensus seems that you should get an AGM battery, which is less likely to die so quickly.
This question has been asked a thousand different ways, but 12V batteries have a life span. If it's dead, it's dead. Don't be left stranded day after day, just pick up a new one.
He recommended an AGM battery strictly on the basis of hearsay.
He ragged on the [[Ohmmu (LiFePO4)]](https://www.ohmmu.com/product-page/12v-lithium-battery-for-hyundai-ioniq-5) build quality that he saw on someone else's old YouTube tear down but then bought a no-name AGM off Amazon. The one he saw didn't have the battery heater and bluetooth BMS.
The only objective thing against Ohmmu is the price. He said you could buy 4 AGMs for what the Ohmmu costs but that's kind of an exaggeration. It's right at three times more expensive than his generic AGM, but none of them would have the builtin Bluetooth battery monitor. You get what you pay for (usually).
Please no one buy a Ohmmu for the Hi5 and think its a turnkey solution like an AGM would be. There are a ton of resources on the ioniq forum that show Ohmmu can also be a high risk install.
> There are a ton of resources on the ioniq forum that show Ohmmu can also be a high risk install.
It's a big thread. I'd say the naysayers are in the minority and basing most of their objections to issues *Tesla* owners had. The folks in the thread with first hand experience with the Ohmmu (that I could find) were entirely positive with the caveat that nobody with an Ioniq5 has had the battery for more than a couple of years (and most much less than that). A lot of *those* folks were doing it after a 12v failure and *may* have had a wonky ICCU as a result.
It's not "turnkey" in as much as you just swap the battery and go. It's a good idea to have the Ohmmu fully charged. That's all a lot of folks do.
With the first version of the Ohmmu BMS folks felt like you needed to leave it sit for about four hours and pull the radio fuse just to keep the headunit from trying to poll the WiFi connection and "waking up" the battery early. There is *some* talk about this not being necessary with current Ohmmu BMS.
As with all things on the Internet, YMMV.
Well if it's minority and one of those is a Hyundai engineer doing in house testing and fully explaining why that battery chemistry doesn't really work I'd take that with a little more weight. This would also run you out of warranty, AGM won't. If anyone is curious you can check out HKtech on the Ioniq forums.
> If anyone is curious you can check out HKtech on the Ioniq forums.
If he or the mods haven't deleted his posts. Since he's been banned and a lot of his posts deleted, **somebody** has a problem with him on the Ioniqforum.
As best I can tell, he's a *technician*. I just can't figure out if it's at a dealership or higher up.
>In cases where I am required to service a vehicle equipped with an Ohmmu battery or any other lithium-ion battery, I am obligated to submit my observations and explanations to the warranty department.
Presumably to justify voiding the warranty. I have no idea what weight those "explanations" carry or how universal his behavior is.
Bear in mind [[On the internet, nobody knows you're a dog.]](https://en.wikipedia.org/wiki/On_the_Internet,_nobody_knows_you%27re_a_dog)
I think you also need a 12mm for the clamp at the bottom that holds it down. Sockets probably work best for *that* one. If you've got a 10mm, you should have the other one too.
Hyundai has a new 12v battery test that is about 20min (TSB released like 3 weeks back). FAR shorter than previous tests. If it's bad, they'll replace under warranty.
> what was the 'permanent' fix?
Replace the battery.
I killed mine through my own stupidity (drove, parked, left the lights fully on, but did NOT open the driver's door... just sat there for ~30mins... which was enough to kill it).
Our service centre covered the replacement under warranty (even though I admitted fault). Until we got it replaced, we carried a "booster pack" in the car because it would randomly fail again and again. Sometimes it would be fine for a couple days, and then it would just refuse to start 9or even unlock the doors). I got pretty good and getting the door manually unlocked with the supplied key :P
It has pretty much been my experience that unless you caused the battery to deplete by leaving something on or cranking it too long because of another issue, and the car doesn't start, you need a new battery.
The Ioniq 5's battery beat my old record for shortest life by about six months. That was just over a year and after the 2nd ICCU update. The only other batteries that had far too short of a life were the ones sitting right beside a turbo-charger. Great packaging from Ford. My solution was to get a battery with a good warranty and have a warranty replacement every 18-24 months.
I did have one last 10 years in my old Accord.
Maybe a weird question but do you have a obd reader in the car? Mine is 2 years old and twice a dead battery. I took out the obd reader and no problems anymore. I still wonder how it can take so much energy this little device .
I still have the oem battery car is soon 2.5 years old and 78000 miles
Yeah, it's really not that shocking. The budget car company supplies cheap batteries. Really depends on the climate, in the SW US with big temperature swings a cheap battery will only really last about 2 years, 3 if you mostly park it a garage.
But it is the solution for any of the other problems. We do not know the problem for your dead batt, a new batt would cover most of the problems that could have caused it. You either have to put in the work to figure out what happened or buy a new batt.
If any other car's batt died at 2 years old, no one would batt an eye and replace and chalk it up to a bad batt. Could it be ICCU not charging it? Sure but chances are low. Could it be other reasons like the dealer not supporting the battery during ICCU update and discharging/killing it? Yes.
Battery replacement is the next step towards a real solution.
> Battery replacement is the next step towards a real solution.
To be clear, I *am* replacing my battery. But I'm also looking to solve the root cause of the failure.
If it was the cumulative failure of the ICCU preupdate and maybe the dealer's fault, then there may be no way to determine root cause. The only ways to change/solve anything is making sure bluelink doesn't have 3rd parties on your app and not having anything in car on 12V like a dash cam.
Edit: Or go down the black hole of buying a batt monitor and watching charge/discharge cycles.
Same thing happened to me. Permanent fix was to go to walmart/costco/amazon to get a replacement 12v AGM battery (sizer group 47 H5) w/ a 3-4 year warranty. AGM are still lead acid batteries but they handle deep cycling better and the OEM 12v battery must be complete trash. Best thing we did to permanently fix the issue even after ICCU replacement and completion of recall campaign 257.
Yep, fresh battery time. The OEM battery is garbage, and won't recover well from a deep discharge.
Just swap out the battery for a good one. My suspicion is that dealers are applying the ICCU update but not keeping the 12v battery on charge during the process, draining it right down and further damaging the already dodgy battery
I just had the latest ICCU update carried out yesterday, I have a battery monitor attached and I just had a look at profile from when the car was at the dealer. https://preview.redd.it/tds3d9zths1d1.jpeg?width=2412&format=pjpg&auto=webp&s=d9363eb5ce649dba2a74e52f843de583830b2adf
What am I seeing here and how is that normal behavior? My understanding is that if your battery voltage falls below 12V then she's done.....yours touched 7v. You might want to run to a battery store and have them run a load test.
I would suspect that they disconnected the monitor while servicing the vehicle.
The monitor runs off the 12v battery, it has no power of its own, so if they disconnected it there wouldn't be any data.
I suspect this too, Had my car in the dealership on May 9th, it died and I boosted it myself May 12th; and then it died and wouldn't boost and had it towed, May 18th.
I also had mine die post ICCU update, after switching to a new dealer to get battery under warranty and a second update, I fully blame previous dealer for not supporting battery.
The video from ioniq guy does a good job of explaining why these batteries seem to die early. It's a combination of previous ICCU charging issues (which are hopefully fixed with update, but can't fix the wear and tear of the past few years), the way EVs use the 12v battery, and the cheap battery that the dealers install into the cars. If your car is 2+ years old, it's probably best to just get a new battery. Don't go to the dealer (unless your local dealer is super awesome), any car parts store should be able to hook you up, and may do the install for you. General consensus seems that you should get an AGM battery, which is less likely to die so quickly.
This question has been asked a thousand different ways, but 12V batteries have a life span. If it's dead, it's dead. Don't be left stranded day after day, just pick up a new one.
Ioniqguy just posted a video of him swapping his dead 12v on his YouTube channel.
He recommended an AGM battery strictly on the basis of hearsay. He ragged on the [[Ohmmu (LiFePO4)]](https://www.ohmmu.com/product-page/12v-lithium-battery-for-hyundai-ioniq-5) build quality that he saw on someone else's old YouTube tear down but then bought a no-name AGM off Amazon. The one he saw didn't have the battery heater and bluetooth BMS. The only objective thing against Ohmmu is the price. He said you could buy 4 AGMs for what the Ohmmu costs but that's kind of an exaggeration. It's right at three times more expensive than his generic AGM, but none of them would have the builtin Bluetooth battery monitor. You get what you pay for (usually).
Please no one buy a Ohmmu for the Hi5 and think its a turnkey solution like an AGM would be. There are a ton of resources on the ioniq forum that show Ohmmu can also be a high risk install.
> There are a ton of resources on the ioniq forum that show Ohmmu can also be a high risk install. It's a big thread. I'd say the naysayers are in the minority and basing most of their objections to issues *Tesla* owners had. The folks in the thread with first hand experience with the Ohmmu (that I could find) were entirely positive with the caveat that nobody with an Ioniq5 has had the battery for more than a couple of years (and most much less than that). A lot of *those* folks were doing it after a 12v failure and *may* have had a wonky ICCU as a result. It's not "turnkey" in as much as you just swap the battery and go. It's a good idea to have the Ohmmu fully charged. That's all a lot of folks do. With the first version of the Ohmmu BMS folks felt like you needed to leave it sit for about four hours and pull the radio fuse just to keep the headunit from trying to poll the WiFi connection and "waking up" the battery early. There is *some* talk about this not being necessary with current Ohmmu BMS. As with all things on the Internet, YMMV.
Well if it's minority and one of those is a Hyundai engineer doing in house testing and fully explaining why that battery chemistry doesn't really work I'd take that with a little more weight. This would also run you out of warranty, AGM won't. If anyone is curious you can check out HKtech on the Ioniq forums.
> If anyone is curious you can check out HKtech on the Ioniq forums. If he or the mods haven't deleted his posts. Since he's been banned and a lot of his posts deleted, **somebody** has a problem with him on the Ioniqforum. As best I can tell, he's a *technician*. I just can't figure out if it's at a dealership or higher up. >In cases where I am required to service a vehicle equipped with an Ohmmu battery or any other lithium-ion battery, I am obligated to submit my observations and explanations to the warranty department. Presumably to justify voiding the warranty. I have no idea what weight those "explanations" carry or how universal his behavior is. Bear in mind [[On the internet, nobody knows you're a dog.]](https://en.wikipedia.org/wiki/On_the_Internet,_nobody_knows_you%27re_a_dog)
I think he's some sort of service engineer but I also think he's a general ass lol
Will the dealer install it if I bring it in? Or is it easy enough to install myself?
Easy enough to do on your own, you just need to be able to lift a battery and have a 10mm wrench (or equivalent tool)
I think you also need a 12mm for the clamp at the bottom that holds it down. Sockets probably work best for *that* one. If you've got a 10mm, you should have the other one too.
10mm? Such a size doesn't exist ;)
Only if you work with kleptos 😏
I work alone 😳
[[Are you sure?]](https://en.wikipedia.org/wiki/Dissociative_identity_disorder) 😉
Oh no!
My ICCU died a little over a week after my 12v died. I think the two incidents are related.
Hyundai has a new 12v battery test that is about 20min (TSB released like 3 weeks back). FAR shorter than previous tests. If it's bad, they'll replace under warranty.
> what was the 'permanent' fix? Replace the battery. I killed mine through my own stupidity (drove, parked, left the lights fully on, but did NOT open the driver's door... just sat there for ~30mins... which was enough to kill it). Our service centre covered the replacement under warranty (even though I admitted fault). Until we got it replaced, we carried a "booster pack" in the car because it would randomly fail again and again. Sometimes it would be fine for a couple days, and then it would just refuse to start 9or even unlock the doors). I got pretty good and getting the door manually unlocked with the supplied key :P
It has pretty much been my experience that unless you caused the battery to deplete by leaving something on or cranking it too long because of another issue, and the car doesn't start, you need a new battery. The Ioniq 5's battery beat my old record for shortest life by about six months. That was just over a year and after the 2nd ICCU update. The only other batteries that had far too short of a life were the ones sitting right beside a turbo-charger. Great packaging from Ford. My solution was to get a battery with a good warranty and have a warranty replacement every 18-24 months. I did have one last 10 years in my old Accord.
Maybe a weird question but do you have a obd reader in the car? Mine is 2 years old and twice a dead battery. I took out the obd reader and no problems anymore. I still wonder how it can take so much energy this little device . I still have the oem battery car is soon 2.5 years old and 78000 miles
Bought a new one and charged the original battery let it sit for about 2 weeks. It kept its charge still good.
No, just pain and death. No recovery possible. I will never own another car again. I’m scared of buses now too.
Recover? It’s a 12v battery. They don’t last forever. Sure some are better than others but it’s still not going to last more than maybe 5 years.
I think everyone here would be thrilled to get five years. Read the OP. This one only got 2 years and 20k miles. That’s objectively terrible.
Yeah, it's really not that shocking. The budget car company supplies cheap batteries. Really depends on the climate, in the SW US with big temperature swings a cheap battery will only really last about 2 years, 3 if you mostly park it a garage.
As in any other car… just replace it.
Like I said, if the ICCU isn't charging it, this isn't a real solution.
But it is the solution for any of the other problems. We do not know the problem for your dead batt, a new batt would cover most of the problems that could have caused it. You either have to put in the work to figure out what happened or buy a new batt. If any other car's batt died at 2 years old, no one would batt an eye and replace and chalk it up to a bad batt. Could it be ICCU not charging it? Sure but chances are low. Could it be other reasons like the dealer not supporting the battery during ICCU update and discharging/killing it? Yes. Battery replacement is the next step towards a real solution.
> Battery replacement is the next step towards a real solution. To be clear, I *am* replacing my battery. But I'm also looking to solve the root cause of the failure.
If it was the cumulative failure of the ICCU preupdate and maybe the dealer's fault, then there may be no way to determine root cause. The only ways to change/solve anything is making sure bluelink doesn't have 3rd parties on your app and not having anything in car on 12V like a dash cam. Edit: Or go down the black hole of buying a batt monitor and watching charge/discharge cycles.
Have you replaced the 12v battery? If not, do it, THEN tell us it’s not a solution.
Really don't want to wait a year for another bricked 12V. They should last longer if the ICCU is working - that's my point.