Monitor real-time voltage to effectively protect storage battery from over charge. It can prolong the life of the battery and avoid the battery loss and overshoot. Suitable for use in household chargers, solar energy, etc.Can be set free start charging voltage and stop charging voltage. On-board momentary push button to set the charging initiation voltage and charging stop voltage.3 digit red LED display the parameter easy to operation.Module disconnect the power supply to avoid battery overcharging.Suitable for lead acid battery and lithium ion battery also compatible with solar panel. Notes:1.Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the pictures.2.Due to the manual measurement and different measurement methods, please allow 1-3cm deviation.