Features: Start charging voltage and stop charging voltage can be freely set, automatically cut off power to save power and extend service life of battery. The board has a bright 3-digit display with 0.1 accuracy shows the setting value. Start or stop according to the set value, and monitor real-time voltage, to effectively protect storage battery from overcharge. Big power screw terminals with large capacity can meet many wiring requirements, maximum withstand voltage 300V, current 20A. Suitable for 220V charger and control charging storage batteries of 12V, 24V, 36V, 48V, 60V, 72V, 84V, 96V, etc. Specifications: Input Voltage: AC 220V Display Accuracy: 0.1V Control Accuracy: 0.1V Output Type: Switch Voltage Error: ±0.1V Size: 86*58*24mm Instruction: How to Restore Factory Settings: Press start and stop buttons together, and display shows 888 to restore factory settings. Common Battery Charging Voltage (for reference only): Voltage Charging Voltage Voltage Charging Voltage 6V 6V~7.2V 36V 36V~46.8V 12V 12V~14.4V 48V 48V~57.6V 24V 24V~28.8V 72V 72V~86.4V Charging voltage generally is not higher than 1.2 times that of battery voltage. For example, if battery voltage is 6 V, charging voltage is between 6V and 7.2 V.Charging current is better to be no more than 1/10 of the battery capacity. preferred.Max. Charging Voltage= Battery Voltage x 1.2;Max. Charging Current = Battery Current x 0.1 Note: 1, The default start voltage is 12V, and default stop voltage is 14V. When setting voltage, if one voltage value is not able to set, you can set the other voltage value first, then set this voltage value. 2, Set start charging voltage according to tested battery voltage when it need being charged(tested by yourself with a voltmeter), and set stop charging voltage according to tested battery voltage when it is fully charged(tested by yourself with a voltmeter). Package Includes: 1 x Protection Board .