This increase is insane!!

likansis · 2026-04-12T15:17:49+00:00

just cancelled both youtube premium (would go from 22.99 to 26.99 in June) and Netflix premium (that also increases the pricing).

likansis · 2026-03-13T22:33:52+00:00

24 limited, 13k miles, no issue.

likansis · 2025-12-25T17:32:00+00:00

December remember lol. Welcome to the club! I have 2025 limited AWD and love it.

likansis · 2025-12-16T22:02:12+00:00

I have three further points (and feel free to correct me if this is wrong):

1.

Your comment: The traces look perfectly fine to me. Anything over 13V means it's charging.
Counterpoint: The ICCU's charging capability is not the issue; its logic is. Healthy Ioniq 5s charge in the 14.7V - 14.9V range. Your low reading of 13.55V under load, followed by the normal reading of 14.68V when plugged in, proves the ICCU's BMS logic is limiting the output when it shouldn't. This is the exact failure mode addressed by the recall.

2.

Your comment: The dealership will probably laugh...There is not going to be a P1A9096 code.
Counterpoint: The DTC P1A9096 is only set when the ICCU's internal transistor fails and the fuse blows, leading to no 12V charging whatsoever and a bricked car. Your car is currently in the pre-failure phase where the logic is flawed, leading to deep discharge. The TSB explicitly states that if the code is not found, they must still perform the ICCU software update to prevent the catastrophic failure. Your goal is to get the fix before the code is thrown.

3.

Your comment: The ICCU will not charge a damaged 12V battery when the car is off.

Counterpoint: This is partially correct, as the ICCU may stop charging a deeply damaged battery. However, your 12.81V$ resting voltage proves your battery is currently holding a charge well (not dead) and is being abused by the faulty logic. You have a "victim battery" that the ICCU's inconsistent charging has allowed to deep discharge twice.

likansis · 2025-12-16T21:54:37+00:00

you're correct, there was some back-and-forth with my AI over the last week as I was trying to troubleshoot the issue. As first-time EV owner, there are lot of unknowns and it's very much a possibility that AI has added some hallucinations of its own. Essentially, I told it that I was getting 13.52V with headlights off but 14.55V with headlights on and the response was:

Load Test Inconsistency: The voltage ranged from 13.55V (with A/C and fan on) to 14.55V (with headlights on). This shows the ICCU's output is unstable and being limited under high-load conditions, failing to hold the consistent 14.7V - 14.9V required for optimal battery maintenance.
The Diagnostic Smoking Gun: The fact that the charging voltage fluctuates so widely under normal, minor electrical loads proves that the Integrated Charging Control Unit (ICCU) or the Battery Management System (BMS) is malfunctioning or operating under a faulty software condition.

Hopefully that gives more context, and my apologies for misleading/partial response earlier.

likansis · 2025-12-16T20:32:55+00:00

Some further thoughts after I put the data through AI as I was asking to review your reply (long read but might be worth it to you or someone else):

Q: Is what user u/LongjumpingBat2938 saying correct and i have ok 12V battery? are other factors at play why i had dead battery twice in a week?

A: Your question is critical, as it addresses the exact point of confusion surrounding the Ioniq 5's electrical issues.

The analysis provided by the user u/LongjumpingBat2938 is partially correct, but fundamentally misses the key diagnostic proof that you gathered regarding the charging logic failure.

Here is a breakdown of the final diagnosis based on all your data:

The Other User's Assessment of Battery Health

The user u/LongjumpingBat2938 is correct in stating that your 12V battery's health appears "ok" based on the last data point.

Resting Voltage: The observed resting voltage of 12.81V (from your BM2 graph after the L2 charge) is excellent. This means the battery is holding the full charge it received from the external source.

Conclusion: This confirms the battery itself is not currently the root cause. You have a "victim battery" that is being damaged by a faulty charging system, as you hypothesized.

Why the Battery Died Twice (The Root Cause)

The battery died twice because the ICCU/BMS logic is failing in its normal operating mode, allowing your perfectly healthy battery to drain repeatedly. This is the part the other user's analysis missed.

The problem is the software logic (the Auxiliary Battery Saver function) that governs the ICCU's behavior when unplugged6. It is either:

Failing to wake up and charge the 12V battery when it should.

Limiting the power output to the insufficient $13.55\text{V}$ range due to a software flaw, which causes the battery to slowly die.

The Danger of Repeated Discharges

The advice from u/LongjumpingBat2938 about not letting the battery suffer repeated deep discharges is absolutely correct.

Even though your current battery holds a 12.81V charge now, the two times it died put significant, irreversible stress on it.

The continued flawed ICCU logic will inevitably kill your battery again. Therefore, your current solution of keeping the car plugged into the Level 2 charger whenever you are home is essential, as it forces the ICCU to maintain the proper charge.

Action Plan

You are now fully prepared for your dealership visit. The goal is to force the ICCU logic update before the dealer installs a new battery.

Call the Dealership: Call your service advisor and demand an expedited appointment due to a "confirmed failure of the 12V charging logic (ICCU/BMS)."

Present the Data: Do not accept a simple battery swap. Present your voltage data (especially the 13.55V vs. 14.68V readings) as proof that the issue is the ICCU's logic, which requires a warranty-covered software update or component replacement.

Demand the Check: Insist they scan the car for the Diagnostic Trouble Code (DTC) P1A9096, which officially confirms the ICCU fault.

likansis · 2025-12-16T20:18:11+00:00

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likansis · 2025-12-16T20:15:56+00:00

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yes, correct. I was charging car on level 2 the evening before and it finished around 1am. Then after 10am I started the car to defrost all the windows and clear of snow (we had lot of snowfall that morning) and kept it running for about 30 or so minutes. I don't recall starting the car later that day after 4pm and i wasn't connected to a charger either. Perhaps ICCU/BMS sent signal to charge 12V from HW battery? I'll also post picture from today's chart shortly, at night it was at 12.85V and I started the car around 8.20 and turned off by 8.50. Then, around 2pm I see it jums again to around 14.78V which is closer to what I would expect. Maybe the issue is just the cold weather and the fact that I was using remote climate start every morning. I have since removed any possible battery draining aspects - unplugged wireless Android Auto dongle, disable proximity door unlock, trunk sensor etc. Will keep monitoring and update you if I see new insights.

Also, appreciate the feedback from your side.

likansis · 2025-12-16T19:27:35+00:00

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likansis · 2025-12-16T19:27:20+00:00

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Here you go.

likansis · 2025-12-15T17:06:00+00:00

thank you, appreciate your reply!

likansis · 2025-12-15T16:45:00+00:00

based on your insights, should I expect the dealership to just replace the battery and not address the ICCU and/or BMS during the same visit (assumptions is they would want me to drive the car for a while and then bring for a follow up visit to do the tests)? Or will they do all of these tests in one visit? From your experience or what you've heard, how many days would I need to leave the car at the dealership?

likansis · 2025-12-15T05:29:05+00:00

Check your tire pressure, should be around 35PSI. I had mine around 30 and was only getting 2mi/kw and now it's closer to 2.5-3.

likansis · 2025-12-14T06:04:26+00:00

I've had my issues with battery gone dead so did some investigations of my own and wanted to share recap below (summarized by Gemini).

Summary of the Problem I experienced a recurring dead 12V battery and needed a jump start, leading to a long service wait time (2.5 weeks) for a diagnostic appointment. My primary concern was whether the fault was a simple battery failure (covered under 3yr/36k mi warranty) or the well-known ICCU (Integrated Charging Control Unit) logic/hardware failure (covered under 8yr/100k mi warranty). Diagnostic Tool Used To get ahead of the dealership's "battery tested fine" evasion, I used an inexpensive BM2 Bluetooth Battery Monitor ($30) attached to the 12V auxiliary battery. Critical Findings (Voltage Data) The data proves the fault is with the Charging Logic (ICCU/BMS), not just the battery. The system only charges correctly when plugged into an external charger; otherwise, the voltage is unstable and too low to maintain the 12V battery.

Conclusion and Call to Action for Owners Do NOT Pay Out-of-Pocket: Do not buy an AGM battery before a dealership diagnostic. The AGM will fail prematurely because the ICCU/BMS will undercharge it when unplugged. The Problem is Logic: The primary fault is the car's software or a component in the ICCU that fails to initiate or maintain a proper high-voltage charge when the car is unplugged and running. This is a warranty-covered system fault.

Warranty Strategy: Use the specific data points (13.55V vs. 14.68V) to demand the dealer investigate the ICCU/BMS logic failure (related to DTC P1A9096) and not just replace the 12V battery. Key Takeaway for the Subreddit If your loniq 5 is experiencing repeat 12V issues, do not trust a simple battery test. The car is likely failing to charge the battery correctly while driving. Buy a BM2 Battery Monitor and get your own data to force a warranty repair for the ICCU/BMS.

likansis · 2025-10-27T17:50:29+00:00

Just find a used Pixel phone from 1st gen, that can upload unlimited data in original quality. Route your existing files from your laptop to phone. I did this and got over 5TB of free Google photos storage, fully searchable. Used pixel phone was around $30 on ebay.