Features Easy Carrying: Comes with small size and lightweight, you can easily take this board with you to help with your work. Accurate Detection: This board features high voltage circuit detection, possesses fine workmanship, durable. MOS Transistor: MOS transistor of this board can control the charge and discharge of the battery. You can take it with confidence! Low Power Consumption: This board is small in size and low in power consumption, with an low standby current consumption. PCB Board: Made of PCB board, this battery balance board is wear resistance, and corrosion resistance, it has a long life span. Specification: Item Type: Lithium Battery Balance Board Material: PCB Charging Voltage: 16.8V-18.1V Continuous Discharge Current (upper limit): 40A (if the cooling environment is bad, please reduce the load current for use) Continuous Charging Current (upper limit): 20A Standard Version: Applicable to electric drills with starting current below 60A and power below 100W. Enhanced Version: Applicable to electric drills with starting current below 80A and power below 135W. Equalizing Version: Applicable to electric drills with starting current below 80A and power below 135W Package List:4 x Lithium Battery Balance Board Note:1: Four 15C to 20C power batteries or eight 10C to 15C power batteries are required to successfully start the electric drill (ordinary 18650 cannot start the electric drill!!!).2: Wiring 0V, 4.2V, 8.4V, 12.6V, 16.8V in strict accordance with the diagram, and do not intentionally short circuit.3: When the load with brush motor is used, try to connect a non polar capacitor (withstand voltage of more than 25V, capacity of 10uF to 100uF) in parallel at the positive and negative terminals of the motor to prevent the reverse peak voltage generated by the motor from interfering with the protection board or breaking through MOS tubes.4: When four groups of batteries are connected in series, please ensure that the voltage of each group of batteries is the same. If not, please fully charge each group of batteries separately and then use them in series. Package List 4 x Lithium Battery Balance Board