SODIAL(R) Dual USB 5V 1A 2.1A Mobile Power Bank 18650 Battery Charger PCB Power Module LED LCD Solar Charging Board for

Output voltage and current stable, will not harm user devices.
This is the mobile power module Accessories, 18650 Circuit board shell.
Meet the individual needs of your DIY, but you must understand basic electronic assembly.
Intelligent output device after charging full, automatically stop charging, to prevent mobile phones overcharge.
Motherboard comes with protection function: Charging overcharge protection, over-discharge protection, overcurrent protection.