Recharges 2 or 4 AAA AA C or D-size or 1 to 2 9V size Ni MH Ni Cd or Hybrid rechargeable batteries at a time Powered by the supplied AC 230V mains adaptor when used in home or DC 12V car adaptor when used in a vehicle Negative delta V detection switches off charger immediately the batteries are fully charged Overcharging prevented by timer protection Automatic charging current selection for different size batteries LEDs indicate when charging properly & when batteries are ready