1. Plastic case (without battery cell) and circuit board are suitable for 20V 60V flexible voltage lithium battery DCB612. 2. If you use new core use 18650 power lithium battery with small internal resistance, same model and same parameters, do not use ordinary lithium battery for energy storage, test the voltage of each and charge each battery so that the voltage of each is the same. 3. If the old battery has been repaired, test the voltage at both ends of each battery. If the voltage is different, charge each battery to the same voltage value. 4. This product is a part without a battery cell. It is used for repairing and assembling battery packs. It is those who are familiar with battery performance and have practical experience in battery assembly. 5. It can hold 10 18650 lithium- batteries with LED battery status indicator, it is only a housing with no batteries inside. The circuit board comes with overheat protection, overvoltage protection, undervoltage protection, overcurrent protection, overcharge protection, all the features and quality are designed to replace the original battery, satisfaction guaranteed. Material: Metal + Plastic colour: As shown Package Contents: 1 set x Battery Packs 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.