The cradle features a spare battery charger - great to have if you have multiple batteries. If you want to use the cradle's spare battery charger, you also need to connect the bundled AC adapter. The AC adapter does not charge your device, it only provides power to the battery slot.

*Note: Phones with an EXTENDED battery/battery door cannot charge in the cradle. The extended battery must be removed from the phone and placed in the spare battery charger.