Kia 7-year EV/HEV/PHEV Battery Warranty. When you switch to a Kia Electric (EV), Hybrid Electric (HEV) or Plug-in Hybrid (PHEV), it’s good to know that our batteries are built to have a long life*. That’s why at Kia we are happy to cover you for 8-years (7-years for HEV & PHEV) or 100,000 miles whichever comes first. For our low voltage 12V batteries and 48V batteries in Kia Mild-Hybrid electric vehicles (MHEVs), our warranty covers you for a period of 2-years from first registration regardless of mileage. All of which means you can simply enjoy the experience of driving our eco-friendly range, every day for years to come.* Kia high voltage lithium ion battery-units in electric vehicles.