Description: 12 V automatic charging power control protection board will automatically charge when the battery voltage drop to about 10.5 V (low voltage adjustable) , and shut off when the power is about 14.4 V (adjustable). Red light on when charging, off when fully charged. Relay disconnect and 220 V input end charging, thereby save energy. Features: 1, Assembled with special voltage control IC and special automobile relay. 2, Small volume and large current. 3, Voltage shutoff accurate and stable. 4, Complete functions and reliable performance. 5, A utomatically charge and shut off. Specifications: Size of PCB: 50 x 32 x 18 mm Default Value: Low Voltage: 10.5 V Shutoff Voltage: 14.8 V (adjustable, might be different) Wiring Method: Please wire according to instruction. Do not change wiring. Instruction: C onnect any wire of 220 V with the COM port of relay, and connect charger with OFF port. The charger must be full bridge rectified output. The DC output voltage can be between 13.8 and 14.8 V. Charging test for the first time: battery voltage should be about 10 V. Function 1: Current cannot be larger than 10 A. Function 2: The board has reverse connect protection function. There is no output if no battery is connected. No output if the polarity of battery is wrong. Output short circuit automatically shut down: It is a practical protection. As long as the output short circuit, the charger will automatically shut down output, so protect the charger from burning. Adjustment: VR1 relay disconnected to shutoff when battery charging voltage to 14.4 V. (shutoff voltage setting: clockwise lower, counterclockwise higher) VR2 relay connected and began to charge when battery voltage is 10.5 V(low voltage setting: clockwise lower, counterclockwise higher) Package includes: 1 x Charging Control Board Note: 1, Users need electric knowledge to use this item , please make sure you know how to use it before you buy. Thanks for your understanding. 2, Please allow 1-3 mm error due to manual measurement. Thanks for your understanding. 3, Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.