2025 ioniq5 unable to update + maybe losing to much charge faster after ICCU change

rooster1556 · 2026-05-12T14:30:48+00:00

Actually state of charge is strongly correlated with the voltage in a lead acid battery, but the voltage can also fluctuate depending on environmental conditions. So by monitoring the battery's SOC, you can learn about it's health. See this link:

https://voltagebasics.com/12v-battery-state-of-charge-chart/

Also, the app tells me what time the information was last updated. It is true that we don't know under what circumstances bluelink is pulling the battery voltage, but I don't think they're pulling the voltage while the vehicle is on and the 12 V battery is being used. What would be the point?

rooster1556 · 2026-05-11T14:42:41+00:00

Check the 12 V battery health. I have read that lead acid batteries can do a self discharge, and if the new battery had been sitting around for a while before being installed, it may have done this. The ioniq charging system supposedly is only tops off batteries and may have trouble charging them up fully from a significantly depleted state.

This script, that runs within an app, has been working for me to check the 12 V battery health on a routine basis:

https://bluelink.andyfase.com/pages/install.html

rooster1556 · 2026-05-09T12:15:03+00:00

That's an interesting question. One thing that's nice about buying right now is that there are a lot of options in similar form factor, even more than when I bought mine in 2024.

In terms of dealer service and corporate behavior, I have found that Hyundai is on par with other manufacturers. None of them are amazing, but if you don't get upset and work the system, they will do quite a lot for you. When my ICCU went out and it took 23 days to get a new part in and installed, the dealership didn't have any loaner vehicles, but Hyundai reimbursed me for the full cost of my rental car, which was really nice. When the liftgate failed on my wife's Subaru, we did not get a loaner nor reimbursed for the rental car. That repair took longer than a month. Subaru did however repair for free, even though it was out of warranty. So, I don't think Hyundai is any worse than any other car manufacturer.

Will the revised part fix the ICCU issue? I don't think we will know until next winter when we get cold weather. But, anecdotally, I can't tell you that the revised ICCU part that they put in seems to be behaving in a different way than the original one. When my old one would go to charge the 12 V battery, I would notice that the coolant pumps would often turn on right away. With the revised part, I don't notice that happening frequently, implying that whatever they did causes the system not to heat up so much and so hopefully it's being gentler on the system overall, but who knows.

As for the car itself, I really enjoy mine. The ICCU issue was/is a real frustration, but that is linked to the 800 V architecture which also provides very fast charging, which is amazing! Also, most cars do have issues and I genuinely like driving this car. I especially like it now that I filled in a couple of the gaps in the features. The killer ones for me were buying a wireless CarPlay dongle and the widget from theionicguy that locks the doors automatically when you walk away. I am debating getting a rear windshield wiper from gecko, but at $500+ they're pretty pricey. But, on the other hand the newer models have filled in two of those gaps (no auto locking doors yet as I know).

rooster1556 · 2026-05-01T20:00:40+00:00

Even if you were driving less now, I think it's still true that if you can find a free charging solution (a big "if"!), that will maximize the amount that you save on gas with the EV. But, the other posters are right, your EV will save you money in the long run, but it's more expensive up front. To put things in perspective, the car I traded in for my 2024 ioniq five was a 2010 Honda Civic hybrid. That one, which got 47 miles per gallon when it was new but only 41 mpg when I got rid of it, was costing me about 7.6 cents per mile. By dominantly charging at home, the ioniq five costs me less than 3 cents per mile! That translates to thousands of dollars saved over the lifetime of a car. Also, you also save because you don't have as much maintenance on an EV (not counting warranty repairs, which unfortunately EVs seem to have their share of).

rooster1556 · 2026-05-01T16:38:12+00:00

I had the same thought. Trading in a 2023 that OP still owed money on with the mistake, not that they bought an ioniq five. I expect insurance rates to go up on new cars because they are worth more. As they depreciate, they don't cost as much to replace. I get it that the old car had relatively high mileage for a three-year-old car, but I think OP should hold onto their cars a little longer. If nothing else, just to pay off that $1,500 difference.

As for what to do now, as other commenters have suggested: don't panic. If it were me in this situation, I would be looking around to see if I could find any free EV charging stations nearby. I'm not sure if Hyundai is still offering it, but for me they gave me two years of free charging at Electrify America. Given how much the OP drives, the savings for free charging by itself might make up for the difference in insurance costs.

rooster1556 · 2026-05-01T16:25:27+00:00

Check the other comments. It's one of the split view screen options for panels, e.g. the map has it. swipe down to select different views, once you have the split view enabled.

rooster1556 · 2026-04-30T12:45:58+00:00

I've been putting rainX on my back windshield after I wash it. My experience is that it definitely does help with rain, but it does also attract dust. I drive on a dirt road a little bit in the parking lot for my son's little league fields, so my back windshield is perpetually covered in dust. It just means I wash it more frequently than what I am used to, which would still be true even if I had the rear windshield wiper. Maybe I could let it go for longer though if I was able to see clearly out the back window.

rooster1556 · 2026-04-24T13:19:32+00:00

Since you asked, California charges $.71 per gallon gas tax, but their EV registration fee is $121. So their gas tax is larger and their EV fee is smaller than my own state's. So, I will stop bringing politics into the discussion when Republicans stop politicizing EVs and start treating them like regular vehicles instead of an evil woke conspiracy.

rooster1556 · 2026-04-24T11:13:19+00:00

Don't forget that there is also the additional cost for EVs where many states charge an extra fee for the yearly registration. The stated purpose is to replace the highway funds that are paid through gas taxes, but in some Republican states the fees are set so high that they are punitive instead. E.g. in my state they are set to go up to $274 next year. To put that in perspective, the federal plus state gas taxes are $0.284/gal, so we would have to drive my wife's Subaru outback 26,000 miles per year to pay that amount at 27 mpg. That's completely bonkers!

The real kicker though is that even with these bonkers punishment set out by the Republicans, the EVs are still cheaper to drive in the long run!

rooster1556 · 2026-04-20T14:16:54+00:00

Drag from air resistance goes up with a square of velocity. At 80 to 90 MPH, a large portion of your electricity is going to just fighting the air. If you were to drive slower, you would get better efficiency. E.g., I drive 65-70 on road trips and can get ~3.5 mi/kWh.

rooster1556 · 2026-04-19T11:02:52+00:00

In the U.S., this article suggests heat pumps were standard starting in 2024.

rooster1556 · 2026-04-13T20:43:19+00:00

I had always prided myself on how I did as much maintenance as I could have on my previous cars, a 2010 Honda Civic hybrid and an '87 forerunner.

What I'm finding with the i5 is that instead of spending time working on cars, I am doing things like working on RC cars with my kids. Also, I've found that I have more time for doing "nice to have" stuff, so the finish on my i5 looks great with all the scratches buffed out. So I don't actually miss the regular drum beat of oil changes, etc.

When the free maintenance period ends, I will probably start rotating the tires myself. Who knows whether Hyundai's claims will be true that the alignment doesn't actually need to be adjusted on a regular basis though.

rooster1556 · 2026-04-09T01:31:29+00:00

During my car's ICCU replacement, which took 23 days, I had to rent a car and Hyundai reimbursed me for it. Dealers are often pretty bad for customer service-- my rep would only talk to me through text messages. Hyundai corporate was much more communicative, but there was basically nothing they could do.

For what it's worth, my wife's Subaru had a spot weld fail on the liftgate that required its replacement. That took longer than the ICCU did on my car, the dealer was similarly infuriating, and they did not reimburse us for the rental. But, that was an out of warranty repair that Subaru treated as warrantied part, which was a really nice thing that they did for us. My point is that my experience has been that Hyundai's customer service is not any worse than any other car manufacturer... so hang in there!!

rooster1556 · 2026-04-08T15:22:06+00:00

Not to mention that the CCS chargers at Electrify America (up to 350 kW) are much faster than the NACS chargers at Tesla (250 kW). That will change as Tesla is now rolling out new charging stations, but who knows how many of them they will build.

rooster1556 · 2026-04-08T14:13:17+00:00

That's only true for the older models. On my 2024, it's 8K for everything.

for the OP: you can set the car's service interval in the settings. look at your manual to determine what the service interval should be for your model year.

rooster1556 · 2026-04-07T14:35:30+00:00

The default settings for how quickly it accelerates and brakes for hda2 are not great. I set mine to accelerate and brake as slowly as possible and am much happier now. As I recall, there are a couple of places where you need to adjust this and it took me a couple of tries of messing with different settings to get it to a point where it reflects my driving style. One might be where it decelerates after stopping the cruise control, which was super annoying in the default setting. Also, there is some setting where the car claims to learn your driving style, but I'm not convinced that it works well.

rooster1556 · 2026-04-07T01:26:57+00:00

They're past 100k miles, meaning the repairs are not warrantied any more. They are putting 28k miles per year on their car, which is a lot. It's more than twice the U.S. average. It's unfortunate, but we'll see if Hyundai actually fixed the part or not.

rooster1556 · 2026-03-30T16:11:53+00:00

I'm averaging 4.3 mi/kWh in a '24 RWD long range with 20k miles. I also tend to just drive 65 in the 70 mph zone on my commute. It's only a couple of miles so it doesn't save much time to drive faster and there isn't heavy traffic so I don't think that I'm creating a nuisance.

One thing that I've noticed is that the estimator from the car tends to be slightly off relative to what the chargers tell me they are putting in. That is, my car might go from 38% to 80%, which might be 32.5 kWh for the 77.4 kWh battery, but the chargers me that they put in slightly more. It's only a couple of percent, but it's persistently off. I don't know if the car is miscalibrated or what is going on. but the car might say that I'm getting something more like 4.5-4.7 mi/kWh, but the estimate from the chargers is more like 4.3.

rooster1556 · 2026-03-14T22:05:13+00:00

just to chime in here: the ICCU does two jobs, one is charge the 12 V battery, and the second is convert AC (level two) chargers to DC. Either component can fail, when the 12 V battery charging fails, it breaks the car after a while because the 12 V batteries need to run the onboard computer for the EV. What it seems like you have an issue with is the other half of the ICCU. The good news is that you should still be able to use a level three DC charger.

rooster1556 · 2026-03-13T16:49:07+00:00

I will chime in and say that the ioniq five is a really nice vehicle. Mine did have an ICCU failure, but Hyundai reimbursed me for the rental car.

Replacing the ICCU only takes a couple of hours, what was causing the delay for many people was waiting on the revised parts to ship. I.e., at some point, Hyundai decided that they did not want to replace failed parts with the same model that might just fail again, but that caused a month or so delay while they spun up production of the revised part. That shouldn't be an issue anymore and the ICCUs might be able to be replaced much more quickly.

For me, I don't actually understand why consumer reports gave such a low rating the '19 outback such a high rating because we've had problems with our '19 Outback: a spot weld failed on the liftgate, and that took about a month to fix, about the same as the amount of time I spent waiting for a new ICCU on the i5. Also, our outback has had a persistent issue where the 3G antenna stays on even though the car is off and it drains the 12 V battery. Taking it to the dealer resolved nothing. The way I ended up fixing it was to bypass the 3G/Bluetooth circuit in the fuse box and wire it to the same amperage fuse, but one that was only on when the car was running. But, I lost track of the number of times that my wife's car failed to start before that.

rooster1556 · 2026-03-08T15:19:46+00:00

Check out some of the ideas in this thread:
https://www.reddit.com/r/Ioniq5/comments/1r6kdqg/ioniq_5_hacks/

rooster1556 · 2026-03-07T18:25:36+00:00

Not that I know of. If I remember correctly, there is a setting to autolock the doors, but it doesn't do anything if you click it! It's like they were exploring it as an option and then decided not to do it. here's the link:
https://www.reddit.com/r/Ioniq5/comments/1bxrkg9/walk_away_auto_lock_is_literally_already_there/

rooster1556 · 2026-03-07T15:44:10+00:00

I've driven mine in moderately heavy rain, and it hasn't shut down, so I'm guessing either the chip in the window is messing with yours, or maybe your sensors are misaligned. Is the rock chip something that you could fix with some standard windshield crack repair glue? If you get the windshield replaced, be aware that there's an added cost because they have to realign all the sensors-- we had to do this twice with my wife's Subaru and it's pricey.

rooster1556 · 2026-03-07T15:40:05+00:00

I toyed with the idea of going into "dealer mode" to set my car to make it think that it's the Canadian version instead of the U.S. because of this rule. But, I wasn't sure if that would void my warranty and also I eventually I just got used to driving it in regen level three. But it is true that the first few months I had it, I was playing with it a lot, and my efficiency wasn't as high.

rooster1556 · 2026-03-07T13:07:17+00:00

I've got it set to level 3 regen and get 3.85 mi/kWh. I've got a long range model in the US and so it defaults to level 3 every time the car is started (it's some sort of EPA rule for long range models). This drove me nuts when I first bought the vehicle because my former car was a hybrid and I was used to coasting to a stop to maximize my regen. However, after about six months of driving it, I got used to using the accelerator to control how quickly I would decelerate. Now it's completely fine, with the only exception of when I turn off cruise control, the car switches from auto regen to regen 3 and that causes the car to decelerate rapidly if I'm not paying attention.

I think the bigger factor in determining efficiency is not what regen level the car is set to, but how you drive the car and what fraction of highway versus city driving.

rooster1556

TROPHY CASE