Ensure your battery is compatible with the battery charger maintainer and operating area is well ventilated and dry. Connect the alligator clips/ring terminals to the DC cable, and then connect the AC cable to the charger. Connect the red clamp (+) to the positive pole and the black clamp (-) to the negative pole of the battery (if the battery is connected incorrectly, error code E - will be displayed on the screen). Connect the charger with AC power source and the charger will begin charging the battery. Once the battery is fully charged, the Battery Power Indicator will show FUL maintain charging for at least 1-2 hours afterwards. Unplug the charger or leave on Float Mode. SPETLEK Automatic Car Battery Charger 12V 6A Smart Fast Charger