Universal AA AAA C D 9V Battery Charger: Charges or discharges 1 to 4pcs AA/AAA/C/D Ni-MH Ni-Cd rechargeable batteries, 1 to 2pcs 9V Ni-MH Ni-Cd rechargeable batteries Smart LCD display: LCD display indicates the charging progress(AA/AAA/C/D Ni-MH Ni-Cd batteries) status: charging, discharging, fully charged or bad batteries.While The LED indicators is for 9V Ni-MH battery only Discharge function: Press the blue button to discharge, LCD displays 'DISCHG' , at the same time, 1-4pcs Ni-MH Ni-CD batteries automatically turn to discharging mode. Then the charger will resume charging mode after completion of discharge