Melt bonding prevention method and battery system applied with the same

A battery system comprising:

• a battery including a plurality of battery cells;
• a first main relay connected between one electrode and a first output terminal of the battery;
• a pre-charge relay connected to the first main relay in parallel;
• a second main relay connected between another electrode and a second output terminal of the battery;
• and
• a battery management system controlling charging and discharging of the battery, and controlling the first main relay, the pre-charge relay, and the second main relay,
• wherein the first main relay, the pre-charge relay, the second main relay, and the battery management system receive a supply voltage from an external lead-acid battery, and
• wherein the battery management system opens the first main relay, the pre-charge relay, and the second main relay when the supply voltage is a predetermined reference voltage or less, closes the pre-charge relay and the second main relay to execute a pre-charge when the supply voltage is higher than the predetermined reference voltage, and closes the first main relay after the pre-charge is completed.