Note 3:When the load of the brush motor is used,try to connect a non- capacitor(withstand voltage above 25V,capacity 10uF-100uF)to the motor's positive and negative terminals to prevent the reverse spike from the motor.Break the MOS tube. Note 4:4 groups of batteries in series,please that the voltage of each group of batteries,if not the same,please fill each battery separately and then use in series.The The Discharge test,the voltage drop faster battery that group is poor battery. Model Number:Lithium Battery 18650 Charger PCB Protection Board Condition:New is customized:Yes Type:Voltage Regulator Application:For Drill Motor Balance Current :100mA 4S 16.8V 40A lithium battery protection board Scope:Nominal voltage of 3.6V,3.7V lithium battery(including 18650,26650,polymer lithium battery) Charging voltage:16.8V-18.1V Continuous discharge current(upper limit):40A(if the cooling environment is not good,please reduce the load current use) Continuous charge current(upper limit):20A Color:green Material:plastic+metal Package Contents: 1* 4S 40A Li-ion Lithium Battery Protection Board Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Battery Protection Board for Drill Motor Charger PCB Protection Board