[KunoMochi]

I would guess the GT uses the same type of battery as the other trims. In the manual for my GT-Line, it's stated that it uses an AGM battery:

If you would like to keep a digital copy of your owner's manual for your car, you can download it from their owner's portal here:

Manuals

owners.kia.com

It makes searching for things in the manual easier. lol

 

[KunoMochi]

I should have included the previous page as well... lol

It states that when recharging, the battery needs between 20-30A of current.