The indicator light shows the device status. It turns red while charging and blue when fully charged. When the battery is low, the light flashes and the device switches off automatically. The Electric Nail File takes approximately 2.5 hours to fully charge and provides about 30 minutes of continuous use. You can use the device while it is charging. The product includes a charging cable but does not come with a charging adapter. Use an adapter with an output current of at least 1 A.