With this charger all 2.3 / 6.9 / 13.8 volt DC sealed lead batteries with a capacity of 2.2 Ah to 10 Ah can be charged automatically. When the connected battery is fully charged, the charging current is reduced to prevent overcharging. The automatic voltage and current control ensures that the connected battery remains fully charged and that overcharging and gas formation are prevented. The charger is equipped with protection against short circuit and against accidental polarity reversal. If the battery is connected to the charger with the wrong polarity, the red LED will light up and the charging current will be switched off.