Description:3-STAGE AUTOMATIC CHARGING: This is a fully automatic battery charger with 3 charge stages. Automatic charging protects your battery from being overcharged. So you can leave the charger connected to the battery indefinitely. 3-stage chargers are suitable for most battery types including Calcium, Gel and AGM, Wet batteries. They may also help restore drained and sulphated batteries. Types of batteries: Most types of lead acid batteries including Calcium, GEL and AGM, Wet,EFB, etc.. Feature:Microprocessor Control (CPU). Switchmode technology: Yes Polarity protection: Yes Output short protection: YesNon battery link protection: Yes Over voltage protection: Yes Over temperature protection: Yes Cooling: Natural cooling Input voltage: 100-240V AC, 50-60Hz Rated output: 6V 2A / 12V 2A Minimum start voltage: 7.0VBattery range: 4Ah - 40Ah Thermal protect: 65'C+/-5'C Efficiency: App. 85%. Compliant standards: CE, IEC60335, EN61000, EN55014 Dimension (L×W×H): 130×75×50mm