RAVPower® Dual Desktop Charger Cradle for Samsung Galaxy S4 S IV - Support Charging Spare Battery (Black Color, Spare Battery Charger, Detachable Case Plate, Compatible without or with a Slim-Fit Case)
RAVPower-Reliable  Affordable  ValueThis dual dock cradle desktop charger lets the phone charge while synchronized with your PC to transfer files and media. A 2nd battery slot is located on the rear of the cradle so you can charge a spare or replacement battery while charging the phone.3-In-1 Features:Synchronize, Charge Phone and Charge 2nd Battery.Dock your phone with or without case cover with the detachable case plate on/off.Phone Charging Slot:Light will turn blue when corresponding to the AC power supply.Red light indicates that battery is charging.Green light indicates battery is fully charged.Battery Charging Slot:Red light indicates that battery is charging.Green light indicates battery is fully charged.Flash Red light indicates battery is not connected well.Note:- Does not work with the extended battery.- Protective case is not over 2mm with detachable case plate off.- If you unplug the battery from the battery charging slot when the battery energy is up to 80% or over 80%,and you plug it again,it cann't charge your battery to 100% fully.But if you unplug the battery when the battery energy is is not up to 80%,and you plug it again,it still can charge the battery to 100% fully.This is to prevent the battery from over charging and damaging the battery.- Phone charging slot can charge the battery to 100%.