3.7V Li-ion Battery Mini USB to USB A Power Supply Module

Features:
This PCB also support charging the battery, simply supply a 5V micro USB source to the charging input and it will charge the connected battery to 4.2V.
Great for mobile power source using Lithium ion batteries (unprotected is also ok).
Connect multiple batteries to the battery input to increase the capacity power capacity.
With iphone recognition circuit, can charge iPhone.

Protection Circuit:
Overcharge protection: 4.3V
Overcharge protection release: 4.1V
Overdischarge protection: 2.9V
Overdischarge protection release: 3V

Specification:
Charging voltage input: 5V 1A
Step up voltage output: 5V 1A max
Transient current: 180uA
Red LED: Charging
Green LED: Charging completed
Blue LED: There is a load in the USB