Unreachable If Statement

I tried to search for an answer similar to this before posting, so please, go easy on me. I've only been working with Java for about a week and a half. In the following block of code, I'm getting an error, regarding an unreachable if statement on line 20, and an error regarding a missing return statement on 30. I believe that I can just set it to return(0); for the last error, but for the first issue, I can't seem to figure it out.

class Droid {

  int batteryLevel = 100;               //created instance variable, batteryLevel
  int hours;                                //created instance var, hours. val not set yet

  public void activate() {              //created activate method, string type return

    System.out.println("Activated. Hello human. How can I help you?");
    batteryLevel = batteryLevel - 5;  //Set batteryLevel to decrease by 5
    System.out.println("Battery level is " + batteryLevel + " percent.");
 } 

 public int chargeBattery(){        //creat int method chargeBattery


  System.out.println("Droid charging...");
  batteryLevel = batteryLevel + hours;  //setting up recharge for droid
  return(0);                    //return 0 or return nothing?

   if (batteryLevel > 100) {   //If battery level is greater than 100
    batteryLevel = 100;                 //battery level is 100
    System.out.println("Your battery level is at " + batteryLevel + " percent");
    return(0);                  //return 0 or return nothing?
   }    

   else {                               //else, print out battery level
     System.out.println("Your battery level is at " + batteryLevel + " percent");
   }
 }





  public static void main(String [] args) {   // Main method 
  }
}