[1.6.4] Problem with custom furnace recipes

Hello, My "Charging Station" is a dual input machine. And what I need is to have a battery that gains durability everytime it goes into the station. Here is what I have so far:

 

private static ItemStack getOutput(int i, int j)
{
         if (i == main_ProcessCraft.BatteryEmpty.itemID && j == Block.blockRedstone.blockID || i == Block.blockRedstone.blockID && j == main_ProcessCraft.BatteryEmpty.itemID)
         {
                 return new ItemStack(main_ProcessCraft.BatteryEmpty, 1);   //add damage code here(add durability) and I already tried adding .damageItem(-1, EntityPlayer); but EntityPlayer can not be use. 
         }
}

Any help will be appreciated!