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. This is the Plastic Case,it can fill 10 pieces of 18650 power li-ion batteries But this is only a shell, there is no battery inside Preparation before assembly: 1. If a new core is used, please note: (1). Please use 18650 power lithium battery and small internal resistance, same model and same parameters, Do not use ordinary lithium battery for energy storage, the discharge rate equal 10c (2). please test the voltage of a single 18650 battery,and charge the single battery so that the voltage of each 18650 battery is 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: that the voltage of each 18650 cell is the same before welding PCB. colour:Black Material:Plastic, metal Package Contents: 1 set x Battery Plastic Case(with 6Ah-Sticker) Only the above package content, other products are not included. Note: Light 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.