How to use: Before charging: Check your battery parameters is compatible to the charger. When charging: 1.Connect the red clamp to the positive pole (+), black clamp to the negative pole (-). 2.Connect the charger with AC power source, the charger will start to operate. 3.Once the battery is fully charged, the battery bar on screen will in “FUL” status. Charging completed: Keep the charged status in 1-2 hours is highly recommended, Then, remove the charger. Product Features: Multiple protection Built in circuit protection guards against reverse polarity, sparks, overcharging, over-current, open circuits, short-circuits and overheating. Wide range of applications 3-stage chargers are suitable for most battery types including Calcium, Gel and AGM, Wet batteries. They may also help re.