The DC charger adopts a well-functioning power supply IC, and the digital logic circuit implements sampling control to automatically detect the status of the charged battery. The charger adopts the charging mode of "constant current-constant voltage current limiting-constant voltage floating charge", which has reached a fully automatic working state, especially suitable for unattended working occasions. The selection of high-quality components ensures the reliability and stability of the product itself, and can significantly extend the service life of the battery.