Voltage Monitoring Function - AV Control, Auto Switch to Trickle Mode After Full Charge 3 Hour Charger Safety Timer, Auto Cut-off After 5 Hours of Standard Charging Temperature Monitoring, Over-Heat Protection Charges From 1 to 4 pcs AA, AAA, 1 or 2 pcs 9V NiMh or NiCd Batteries 4 Independent Charging Channels. 2 LED's Indicate Charging Status Bad Battery, Alkaline and Primary Battery Detection Supplied with 4 x 1700MAH Rechargeable Batteries Complete with 12V Car Adaptor