This is diy Dual USB 5V 3A Power Bank Module which can be used with 18650 3.7v Cell or any li-ion battery.You can easily make your own power bank using this Power Bank Module. It has battery level indication with in.

Features:

1.  Over Charging Protection
2.  over-discharge protection,
3.  Intelligent output device after charging full
4.  Automatically stop charging, to prevent mobile phones overcharge.
5. The stable Output voltage, will not harm user devices.

Specifications:

1. Micro USB input: 5V 1A/2A
2. USB Output: 5V 3A (Dual USB interface)
3. Charging display: intelligent led level
4. Batteries Type: liquid lithium-ion batteries (18650) 3.7 lithium-ion battery
5. Product Size: 57mm x 28mm (approximately)
6. Screen size: 27mm x 17mm (approximately)

Installation instructions:

The circuit board is connected to the battery negative B-, B + is positive, do not connect reversed, connecting reversed will burn the board, the battery is connected in parallel, assembling the 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.

Package included:

1. 1 x Mobile Power Bank 18650 Battery Charger PCB