The phone comes with a rechargeable battery. Keep the battery charged while not in use in order to maximize talk, use, and standby time. The battery charge level is shown at the top right corner of the screen.
Use the fingertip cutout at the bottom of the phone to remove the back cover.
Align the battery contacts with the terminals in the battery compartment and push the battery down until it clicks into place.
Place the back cover over the battery compartment, then press it downward until it clicks into place.