KOOBOOK 2Pcs 3.7V Turn 5V 2A Boost Step Up Module Dual USB Charging Circuit Board PCB Board 4-Level LED Light Display for 18650 Lithium Battery Mobile Power Bank DIY

Description

Specifications:
Input port: MicroUSB (Android port)
Input requirements: 5V constant voltage power supply, the most suitable charger is 5V1A or more
Output port: USB
Output parameter: 5V1A/5V2A

Rechargeable battery requirements:
Available batteries: 18650 battery, mobile phone battery, flat battery, MP3 battery and other 3.7V-4.2V polymer lithium battery, can be powered by single section (chip), or multi-section (chip) parallel power supply (does not support series, because parallel increase Capacity, series is to increase the voltage, can only be used in parallel!)
Unavailable battery: dry battery, battery, 1.2V rechargeable battery, nickel hydrogen battery, 3.2V iron lithium polymer lithium battery.

Note:
The batteries should be connected in parallel, the voltage should be between 3.2-4.2V, the 18650 flat head and the polymer battery can be used;
The battery is connected to the motherboard B+, negatively connected to B-, the positive and negative poles are reversed, and the motherboard must be burned;
New and used batteries and models with inconsistent batteries cannot be mixed.

We highly appreciate all customers opinions to improve the selling, also if anything you unsatisfied, please contact us for probable best solution.

Package Includes: 2Pcs