1. Built-in IC detects cell voltage current. And remember the number of uses! 2. Detection and protection battery:Overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overcharge protection. 3. all the series of Makita achieve low voltage shutdown. Cooperate with many power tool factories! 4. PCB design may change due to changes in the supply chain and processing technology. 5. Suit for Lomvum Zhipu Hongsong Jingmi (no Original Makita) 18V Lithium Battery; note: This product is component without battery core. It is used to repair and assemble batteries pack, only for people who are familiar with battery performance and have practical experience in battery assembly. Preparation before assembly: 1. If a core is used, please note: (a). 18650 power lithium battery core must be selected; (b). A group of six cores must be equipped with resistance and capacitance to make their voltage the same. 2. If the old battery is repaired, please test the voltage at both ends of each cell. If the voltage is different, please charge each cell to the same voltage value. Very important: Ensure that the voltage of each cell is the same before welding PCB. Specifications: 10-Hole colour: black Material: plastic Package Contents: 4 set x Battery Case Due to Different production batches, Some accessories have different colors and appearances, but have the same function