1. Built-in dual ICs detect the voltage of each battery. and remember the number of uses. 2. Each battery can be detected and protected. Overheating protection, overvoltage protection, undervoltage protection, overcurrent protection, overload protection. 3. The new for series realizes low-voltage shutdown. Cooperate with many power tool factories 4. Stable quality and shock resistance. It is the best partner for torque wrenches, impact drills and angle grinders. 5. Suitable for BL1850B/BL1840B lithium battery pack. High discharge rate: 15A Maximum discharge current: continuous 60A, pulse a Discharge termination voltage: 13.75V Overcharge protection voltage: single cell 4.25v0.025v Overcharge protection recovery voltage: 4.1V0.025v Over-discharge protection voltage: single cell 2.7V0.08v Over-discharge protection recovery voltage: single cell 3.0V0.08v High temperature charging protection: 602 Discharge overcurrent protection 1: equal 100A/1s delay protection Discharge overcurrent protection 2: equal 180A/100ms delay protection Short circuit protection: equal 200A Preparation before assembly: 1. If using a new , please note: A. Must choose power lithium battery, B. A set of six iron cores must be equipped with resistors and capacitors to make their voltages equal. 2. If the old battery is repaired, please test the voltage of each battery. If the voltage is different, charge each battery to the same voltage value. Very important: Before soldering the PCB, make sure each battery has the same voltage. Due to different product batches, the appearance , which does not affect the use. Colour:Green Material:PC Package Contents: 2 x PCB circuit board(OnlyPCB board, other accessories not included) Only the above package content, other products are not included. Note: Light reflection 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.