, No Battery Cell! 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. Lithium battery shell sleeve is suitable for 10.8V12V BAT411 BAT420 BAT412A BAT413A lithium battery, it can fill 3 pieces of 18650 li-ion batteries. This is only a shell, there is no battery inside. 1. What should be paid attention to when assembling pack? 18650 power cell, model, voltage, internal resistance should be consistent, consistency is better, 10.8V 3 strings, 14.4V 4 strings, 18V 5 strings. The voltage detection line must be connected to the detection line. Try to use better batteries instead of dismantling the electric core. Need spot welder. 2. When the protective plate is used to replace the Before changing the protection board, be sure to measure the voltage of each group of 18650 cells to that the cell voltages are consistent. The protection board only plays a protective role and cannot balance the voltage. The battery cannot be or discharged due to the inconsistent voltage of the battery pack. It is useless to replace the protection board. It is recommended to use 18650 batteries. Please be kindly noted: If you have any objection to the following two items, please do not order! (1). PCB color may be any color according to our stock, (2). PCB design may change with the same function and performance guaranteed. (3). The number and position of components on the PCB may change and be adjusted. Colour:Black Material:plastic The color of the protection board is random, don't accept the specified, and the battery is not included Package Contents: 1 x BAT411 Li-ion Battery Case 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.