No Original, , No Battery Cell !!!!!! It can fill 10 pieces of 18650 power Li-ion batteries. But this is plastic shell, there is no battery inside. 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. Notes:After combining the battery pack and this protective board, if there is no voltage output during the initial power on, please activate it with a dedicated charger. Precautions for use and assembly: 1) When welding battery leads/sampling points, be careful not to connect them incorrectly or in reverse. If a wrong connection is found, the circuit board may have been and needs to be retested before it can be used again. 2) During assembly, the BMS should not directly contact the surface of the battery cell to avoid damaging it. The assembly should be firm and reliable. 3) Electronic devices used for welding must be reliably grounded, and attention should be paid to electrostatic protection to prevent damage to the protective board caused by electric leakage and static electricity Preparation before assembly: If a core is used, please note: a. 18650 power lithium battery core must be selected, b. A group of 5/10 cores must be equipped with resistance and capacitance to make their voltage the same. Very important:Ensure that the voltage of each cell is the same before welding PCB. The color of the protection board is random, no specified color is accepted Color: Black Material: plastic Package Contents: 1 x Li-ion Battery Case 1 x PCB Circuit Board 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.