After operating the phone for an extended period of time, the battery will deplete. With regular use, a battery will lose its charge within 24 hours of the phone's separation from the charger. If your battery starts to deplete quicker than it used to, you should replace the component. This guide tells you how to replace your current battery with a new one. Replacement batteries are easily found online via a Internet search.
Turn off the phone using the "Power Button" located on the left side of the phone.
Slide your fingernail along the edge of the device and pull at the panel as shown in the figure.
Remove the plastic backing by pulling at it gently after hearing the snap.
Remove the battery from the device by pulling up on the battery edge.