Detail: 1. Built-in dual ICs detect the voltage of each battery. And remember the number of use. 2. Each battery can be detected and protected. Overheating protection, overvoltage protection, undervoltage protection, overcurrent protection, overload protection. 3. FOR The new Makita series realizes low-voltage shutdown. Cooperate with many power tool factories 4. Stable quality and shock resistance. It is the best partner for Makita torque wrenches, impact drills and angle grinders. 5. Suitable for BL1850B/BL1840B lithium battery pack. Specifications: High discharge rate: 15A Maximum discharge current: continuous 60A, pulse a Discharge termination voltage: 13.75V Overcharge protection voltage: single cell 4.25v±0.025v Overcharge protection recovery voltage: 4.1V±0.025v Over-discharge protection voltage: single cell 2.7V±0.08v Over-discharge protection recovery voltage: single cell 3.0V±0.08v High temperature charging protection: Greater than60℃±2℃ Discharge overcurrent protection 1: ≥100A/1s delay protection Discharge overcurrent protection 2: ≥180A/100ms delay protection Short circuit protection: ≥200A Preparation before assembly: 1. If using a new kernel, 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. Please note: the physical slightly color difference or difference, number or different, but does not affect the use, please do not mind, thank you Material: plastic colour: Green Package Contents: 1 x PCB circuit board(Only PCB board, other accessories not included)