3pcs 5V 2.1A 3 USB Mobile Power Circuit Board Boost Module For DIY Power Bank Lithium Battery

Features: - 3 USB charging interface for charging up to three mobile phones simultaneously - Dual IC control, synchronous rectification, high conversion rate of 90% - Advanced mass inductance, double tube rectifier performance - Over discharge, over charge, overload protection circuit - Automatically recognizes the output current of 5V1A or 2A according to the device - Board size: 65x19x9mm - Suitable for 3.7-4.2V rechargeable lithium batteries, such as mobile phone batteries, flat batteries, 18650 batteries, etc. Note: 1. The first use requires Micro USB port to activate once. 2.Please note that when the lithium battery is connected incorrectly, the board will be damaged. Please check carefully. Package Included: 3 x 3 USB Mobile Power Bank Module