Kia’s flagship EV has a battery problem

I realized first that there was a problem with the Kia Photo of EV9 when I tried to unlock my car last year. A three-row SUV was sitting in my lane completely dead. The key didn’t work, the app connection to the car was dead, and I was already late. Fortunately, I was prepared for this, having read about the 12-volt battery capacity of the EV9.

I was able to open the car with the manual key that Kia provides and get the frunk to get to the 12V battery and use the booster I bought to get it back to life. Like most ICE cars, the 12V battery uses a lot of low current in the car, so when it dies, the car is useless. I called my Kia dealership to report the problem. I was prepared for the 12V battery issues, but I wasn’t prepared for what happened next.

A few weeks after Kia rolled out a software update to address the 12V battery issue, I started experiencing charging issues with my EV9. Every time I try to charge 80 percent, the car jumps from 82 percent to 100 percent on my home AC charger, as if it had miraculously charged the last 18 percent. I also noticed that the car’s charge dropped significantly at 100 percent, making it difficult to complete long trips without recharging.

It looked like a battery problem, the kind of thing I’ve read many people posting on EV9 owner groups on Facebook. I reported the problem to Kia and they couldn’t repeat it until I was able to record the issue on my phone and charge it on a DC charger. The car can go down to 0kW at a rate of 82 percent and it takes about 10 minutes to make a false ramp up to 100 percent without a lot of changing traffic.

After watching various YouTube videos, I purchased an On-Board Diagnostics (OBD) scanner to get into the car to get battery information. OBD II scanners allow you to see how much power is left in the battery right now, as well as read the voltage levels on the EV battery cells.

The EV9 has a modular battery pack that has been around much appreciated and the engineering firm of Munro & Associates. It has 38 interchangeable modules, making it easy for technicians to complete maintenance. With the OBD II scanner, I could see that on a 100 percent charge I only had 71kWh, when I should have had 96kWh used on a 99.8kWh battery. This means that I need 25 percent of battery and 25 percent of color. I could also see that some of the battery cells were dead and had no charge, but the car was still working and there were no errors or problems charging up to 82 percent.

After several diagnostic sessions, my local Kia dealer determined that the main power pack was faulty and needed to be replaced. Instead of leaving it in the garage for a week or two, I went into Kia’s battery repair program, which has no ETA and is part of the eight-year cover that Kia offers for EV batteries in the UK.

I soon learned after talking to more than a dozen EV9 owners in the UK that the wait could be as long as nine months for a battery repair, the same time it takes to create another future passenger in the back seats. Unlike the EV9 owners I’ve been talking to, I’ve been able to continue using my car until Kia is ready to fix it. Other EV9 owners have had problems similar to mine, where the car stops charging at some point with various nosedives. Others have had the battery pack fail completely or have seen the range drop to 30 miles, rendering their vehicles unusable.

Kasem Saowijit described his EV9 battery failure issues as “terrible” in messages to Seaside. His EV9 failed in January and his local garage offered the smaller EV6 as a courtesy car while he waited an unknown amount of time for his car to be back. “Kia is miserable, they don’t change and drive, and when I get changes it’s useless,” says Saowijit. His EV9 is only a year old, and he says he is now spending hundreds of pounds a month on a lease on a car he won’t use.

Saowijit isn’t the only one with frustrations with Kia’s customer service. “My car has been at the dealership and hasn’t been moved in five months,” explains EV9 owner Helen Crawforth in a message. Crawforth has also been given a courtesy car, but it’s an ICE car that he says is “costing me a lot of money.”

Blair Ogilvie started having problems with his EV9 in September 2024. “The first issue was a 12V battery problem,” he says in a message. After a few months, like me, he started having problems with the large-capacity battery not charging properly and his EV9’s rate dropping too low. The battery failed again in December and dropped to 80 kilometers of range, causing “other systems to fail to engage the emergency braking system.” Ogilvie tells me that Kia said the car was unsafe to drive, and its EV9 has been off the road since December with no ETA on the plan.

The stories from more than a dozen EV9 owners I’ve spoken to are all very similar and point to Kia struggling with battery replacements for its EV model. But the problems with Kia and Hyundai EVs go deeper. The sibling brands, operating under the Hyundai Motor Group, have experienced various problems with the failure of the Integrated Charging Control Unit (ICCU) in recent years across the Ioniq 5, EV6, and other models. An ICCU failure can cause the car to lose power while driving, which is a very dangerous problem to have.

Hyundai and Kia have both begun releasing information about the affected vehicles worldwide in recent weeks, after years of silence. A change of heart came a few months later Consumer Reports is featured in February that up to 10 percent of Hyundai and Kia EV owners experienced issues related to ICCU, depending on model and model year.

Corbin, who runs The Ioniq Guy The YouTube channel and goes by the same name, has been describing the failures of the ICCU very close to its Ioniq 5. battery problem last fall. “What you are experiencing with your car is what I experienced with my Ioniq 5,” Corbin says in an email to Seaside. “They replaced the battery within two weeks, which seems to have happened because others have been waiting months.” Hyundai then loaned Corbin an Ioniq 5 press car while his car was repaired, and it did he suffered the same. “Hyundai became aware of the issue with the cells in early 2025 and released a technical service information instructing dealers to replace the failed packs that showed related problems,” says Corbin. Kia has yet to issue a similar document for the EV9, and my local dealer has struggled to find a specific fault for the problems I’ve been experiencing.

EV9 owners in the US are also experiencing similar battery issues, but messages on owner Facebook groups suggest that wait times are slightly better than across the Atlantic. “The wait times would be shorter but I’ve heard estimates that it could still be months,” says Corbin.

I reached out to Kia PR in the UK about battery issues with the EV9 and ICCU issues at the end of March. After I first responded in March about my claim, Kia UK PR ignored my repeated requests for comment earlier this month.

Two days after driving the Kia UK PR for the first time since March, my local dealer called to say that my car was ready for an emergency repair. My EV9 has now been in the factory for about 100 miles, and I don’t know when I will get it back. Kia has loaned me the smallest EV3 for my growing family at the moment, a car that has also been plagued by ICCU problems for the past 18 months.

Before Kia’s ICCU news, the brand was also hit by a car theft crisis during the pandemic. Thieves call themselves “Kia boys” posted videos on TikTok and other social media sites with tips on how to hack Kia cars, usually with a USB cable. The lack of electronic immobilizers on most Hyundai and Kia vehicles manufactured between 2015 and 2019 led to both models being releasing software updates to prevent theft. It is unclear whether Kia and Hyundai can solve the ICCU and battery and software problems this time.

If you’re experiencing similar problems with your Hyundai or Kia EV – whether it’s an unexplained loss of power, charging problems, or unusual battery behavior – it’s important to take the time to scan your vehicle with an OBD II reader and check the health of the high-speed battery yourself. There are many easy to follow are available, and the data can reveal problems long before the seller accepts them. As owners document these failures, it’s hard for Hyundai Motor Group to ignore what appears to be a growing battery problem.