Quick. and easy! This charger is for use with Power Wheels 12-volt battery systems with one gray battery. A built-in indicator shows the battery charge status so you can easily see when the battery is ready for use: Solid red light: Charging Flashing Green: Quick charge complete-ready for use! Solid green light: 100% charged Flashing Red: Error-wrong or dead battery. Please note: This product is not intended for children; for adult use only.