This is used for making mobile power banks,this is having 18650 Circuit board shell.
Used for making your own power bank and it is having several handy features to make your build easy.

Features:
-The board have circuit protection function:
-overcharge protection, over-discharge and over current protection.
-Full charge indication.
-It automatically stops charging once it is fully charged.
-Output voltage and current is stable, will not harm the used device.

The circuit board is to be connected to the battery negative B-, B is the positive, do not connecting reversed, connecting reversed will burn the board, the battery is connected in
parallel welding, assembling battery. Note that the insulation between the battery and the circuit board, battery lead not to touch the circuit board, so as not to cause a short circuit.