Section 2A: Your PCS Vision Phone - The Basics 21Using the Travel AdapterTo use the travel adapter provided with your phone: Plug the round end of the AC adapter into your phone and theother end into the electrical outlet. A red light on the phone lets you know the battery ischarging. a yellow light on the phone indicates that there is aproblem charging the battery. A green light indicates that the battery is at least90 percent charged.It takes approximately 4 hours to fully recharge a completelyrundown battery. With the Sprint-approved Li-Ion battery,you can recharge the battery before it becomes completelyrun down.When the flip is open, an animated battery icon is displayed on thescreen. When the flip is closed and the battery is completelycharged, a green light is displayed continuously.