I’m a little late to this but I have been dealing with the same exact issue with my ‘23 Sportage PHEV. Purchased new in January ‘24.
In May ‘24 I went away for 3 days and left my car at the airport, came back to it completely dead. Jumped the car (the PHEVs don’t have the battery reset button) to be able to get home and scheduled a service appointment for a few days later. When I brought it in they found nothing in all the diag tests and couldn’t replicate the issue. They told me jumping the car resets the computer & error codes, so if it happens again don’t jump the car and have it towed.
In May ‘25, I again went away for 8 days and left my car at the airport and came home to it completely dead. I had it towed and called everyone under the sun letting them know to not jump the car so the error codes could be read, which was a task in itself. After 5 or 6 days at the dealership, the only thing they found was a dead battery. No parasitic draws, no error codes. They told me the noises from the planes probably set the alarm off which drained my battery — this is simply not true, I have the Kia Access app which tells me when the alarm goes off. So they replaced the battery and sent me in my way.
In October ‘25, again was gone for 6 days and this time I intentionally left my car at home and plugged in since they had told me the planes caused it to die. Came home and the car was dead. I immediately called the dealership and they told me to bring it in when th service dept opened a few days later, so jumped the car and went about my day. Ran all my post-vacation errands with no issues, woke up the next day and the car was dead again. Jumped it again and drove directly to the dealership to drop it off. The car has now been there for a full 14 days, and again the only thing they have found is a dead battery. No error codes, no parasitic draws, no electrical faults, no issues with the battery management system. All the tests were clean as a whistle. They have mentioned several other things besides planes that can drain the battery, and I have none of them. So again they have just replaced the battery and sent me on my way with no answers.
This has been an absolute nightmare of an experience with Kia, there is very clearly something wrong with this brand new car that they can’t or won’t find. It’s really a shame because I absolutely love the car, everything from how it drives to the aesthetics. It’s the first new car I’ve ever bought myself and the experience has been spoiled by this recurring issue. I’m beginning the process of a lemon law claim because this loss of use & inability to fix the problem at the dealership is just unacceptable at this point.