Ioniq 5 power windows not working after battery replacement

Hmm, that's odd. Battery replacement shouldn't directly cause that. The window regulator has a motor and a control unit. The control unit needs to 'learn' the upper and lower limits of the window travel. This 'learning' or 'initialization' is often lost when power is interrupted. Are you sure all the connections to the window switch and the door panel wiring are solid? Have you tried any basic window troubleshooting, like holding the window switch up for a few seconds after it's fully closed, and down for a few seconds after it's fully open? This sometimes resets the system.

Thanks, I'll double-check the connections. Is there a specific procedure for the window reset you mentioned, or is it just holding the switch?

Yes, just holding the switch. The car's computer needs to relearn the window's travel limits. If that doesn't work, it's possible the battery replacement caused a voltage spike that damaged the window regulator's control module, or corrupted its memory. Sometimes these modules need to be reprogrammed by a shop with the right diagnostic tools. Alternatively, the window regulator motor could be faulty. If you've checked the connections and tried the reset procedure without success, I'd recommend taking it to a workshop.

Thanks for the advice. I took it to the workshop and they confirmed it needed a window regulator initialization. Cost me 290€, but at least it's fixed.