Yes. You can use a 12-volt battery in a 6V volt power wheels car. However, the 8-volt power wheels are not designed for 12-volt batteries. But if you want to get the best results from it, you need to make some adjustments to the car's wiring system and electronic components, such as converters and motors. If you do not replace the battery with other components, your power wheel may be damaged. It's important to read the instructions that come with the power wheel to make sure you're doing everything right.