The Kia 7-year warranty that you’re referring to covers the battery—but only in electric vehicles (EVs). So unless you have the Niro EV or the EV6, this particular warranty doesn’t pertain to you.
If you have a gas-powered vehicle, Kia will still cover your battery for up to three years or 36,000 miles. This is a part of Kia’s new vehicle warranty, which covers many parts for up to five years and 60,000 miles, although the battery warranty clocks in at just a bit less.