How to change battery in Kia key fob?

Yesterday, me and my girlfriend went out of town. We had a problem with her car in a park. The remote couldn’t unlock the car, so we used the key to open it manually. But then, the car alarm started going off randomly and wouldn’t stop. When we tried to start the car with the key, it didn’t work, and the alarm kept going. We thought the battery might be low, so we jumped the car and it started working better, showing a message saying “System check” on the screen.

But when it got dark, the park closed, and we couldn’t leave because the car was still acting up. We called for help from Kia’s roadside service, and after waiting for a long time, a tow truck finally came. The tow truck driver couldn’t fix the problem either, but he suggested we try changing the battery in the key fob. Luckily, I had a spare key fob with me, so we changed the battery and the car started working again.

When I tested the old battery, it seemed fine, so I’m not sure why changing it made the car start.

I have a few questions:

  1. Should the car be able to start even if the key fob battery is dead or low?
  2. Should we take the car to the dealer to check the alarm system since it’s still under warranty?
  3. Any other advice or suggestions? We just want to make sure the car is okay. Thanks!