Charges either Ni Cd or Ni MH rechargeable batteries type must be selected prior to charging Charges 1-4 pieces of AAA & AA batteries Independent charge channel for each battery Trickle charge function keeps batteries topped up when fully charged Overcharge over discharge short circuit & reverse polarity protection Negative delta V detection switches off charger immediately the batteries are fully charged LEDs & LCDs indicate charging status of each individual battery Worldwide voltage range 100V-240V subject to use with a suitable travel adaptor Faulty battery detection 1-2 hours average charge time