Detail: 1.The two built-in ICs detect the voltage of each battery.And remember the number of uses. 2.Each battery can be detected and protected.Overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overload protection. 3.Makita new series realizes low voltage shutdown.Cooperate with many power tool factories! 4.Stable quality and impact resistance.It is the best partner for Makita torque wrenches, impact drills and angle grinders. 5.Color: Green 6.Suitable for BL1850B/BL1840B lithium battery. Specifications: High discharge rate: 15A Maximum discharge current: 60A continuous, pulse a Discharge termination voltage: 13.75V Overcharge protection voltage: single cell 4.25V±0.025V Overcharge protection recovery voltage: 4.1V±0.025V Overdischarge protection voltage: single cell 2.7V±0.08V Overdischarge protection recovery voltage: single cell 3.0V±0.08V High temperature charging protection: >60℃±2℃ Overdischarge protection 1: delay protection ≥100A/1s Overdischarge protection 2: delay protection ≥180A/100ms Short circuit protection: ≥200A Preparation before assembly: 1.If you use a new core, please note: A.Must choose a lithium battery, B.A set of six iron cores must be equipped with resistors and capacitors to equalize their voltages. 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 that each battery has the same voltage. Package Included: 1 x Circuit Board (Only PCB Board, other accessories not included)